HIGHWAY RESEARCH BOARD

RESEARCH REPORTS

No. 2 F

USE OF CALCIUM CHLORIDE

IN

GRANULAR STABILIZATION OF ROADS

BY

F. L. CUTHBERT

1945

HIGHWAY RESEARCH BOARD

RESEARCH REPORTS NO. 2F .

USE OF CALCIUM CHLORIDE IN

GRANUUR STABILIZATION OF ROADS

A REVIEW OF

AVAILABLE LITERATUBE

HI F. L. CUTHBERT

RESEARCH MGENEER, HIQflVAY RESEARCH BOARD

HIGHIVAY RESEARCH BOARD DIVISION OF ENCaiNEERING AND INDUSTRIAL RESEARCH

NATIONAL RESEARCH COUNCIL

WASHINGTON 25, D. C. NOVEMBER 1945.

NATIONAL RESEARCH COUNCIL

The National Resetirch Council i s a cooperative organization of the

s c i e n t i f i c men of America. I t s members include, however, not only scien­

t i f i c and technical men but also business men interested i n engineering and

industry. I t was established i n 1916 by the National Academy of Sciences.

The charter of the National AcadenQr of Sciences passed by Congress

and approved by President Lincoln i n 1863 provides that "the Academy s h a l l ,

whenever called upon by any Department of the Government, Investigate ex­

amine, eiqperlment and report upon any subject of science or a r t . "

DIVISION OF ENGEINEERING AND INDUSTRIAL RESEARCH

OFFICERS

Chairman Frederick M. Feiker Vice Chairman Hugh L. Dryden

11

HIGHWAY RESEARCH BOARD

The Highway Research Board I s organized under the auspices of the Division of fhgineering end I n d u s t r i a l Research of the National Research Council. I t s purpose i s t o provide a national clearing house f o r highway research a c t i v i t i e s and information. The membership consists of 36 educa­t i o n a l , technical and I n d u s t r i a l associations of national scope. Associates of the Board are firms, corporations and individuals who are interested i n highway research and who desire t o farther i t s work.

I n ' i t s p r a c t i c a l workings the Board provides a forum f o r the d i s ­

cussion and publication of the results obtained by in d i v i d u a l research

workers; organizes committees of experts to plan and suggest research work

and to study and correlate r e s u l t s ; publishes and otherwise disseminates

information; provides a research information seirvlce; and carries on f a c t

finding investigations. With the cooperation of the highway departments

of the States and t e r r i t o r i e s and the Public Roads Administration, the

Highway Research Board conducts a Highway Research Correlation Service.

I t i s the function of t h i s Service t o aid the many highway research agen­

cies to correlate t h e i r work through personal v i s i t s , conferences, com­

mittee work and d i s t r i b u t i o n of pertinent information.

HIGHWAY RESEARCH BOARD

1945

Officers

Chairman Stanton Walker Vice Chairman R. L. Ubrrison Director Roy W. Cnun Associate Director Fred Burggraf

Executive Committee

Ex-Officio, T. H. MacDonald, Commissioner, Public Roads Administration Ex-Officio, Frederick U. Feiker, Chairman, Division of Ekigineering

and I n d u s t r i a l Research, National Research Council £x-Cfficlo, Hal H. Hale, Executive Secretary, American Association of

State Highway O f f i c i a l s Pyke Johnson, President, Automotive Safety Foundation R. A. Moyer, Research Associate Professor of Highway Engineering, Iowa

State College F. V. Reagel, fhglneer of Materials, MissouirL State Highway Department Stanton Walker, Director of Engineering, National Sand and Gravel

Association R. L. Morrison, Professor of Highway Engineering and Highway Transport,

University of Michigan J. S. Williamson, Chief Highway Commissioner, State Highway Department

of South Carolina Burton W. Marsh, Director, Safety and T r a f f i c Engineering Department,

American Automobile Association Charles M. Upham, £nginee]>-Director, AmezrLcan Road Builders Association

DEPARTMEMT OF SOILS INVBSTIGAUONS

C. A. Hogentogler, Chairman

Committee on Granular Stabilized Roads

Special Subcommittee

H. F. Clemmer, Chairman, Engineer of Materials, D i s t r i c t of Columbia Highway Department

Shreve Clark, Engineer of Tests, Virginia Depairtment of Highways L. D. Hicks, Assistant E^iglneer, Materials and Tests, North Carolina

Highway and Public V/orks Commission C. A. Hogentogler, Public Roads Administration H. R* Smith, Solvay Sedes Corporation J. F. Tribble, Assistant Construction Engineer, Alabama State Highway

Department E. A. W i l l i s , Senior Engineer, Engineer Board, Corps of Eiigineers Fred Burggraf, Highway fiesearch Board

I v

TABLE OF" CONTEIITS

Page

Foreword v i

Introduction 1

History of Stabili z a t i o n 1

Calcium Chloride

Uanufacture and Occurrence 2

Deliquescence and Hygroscopicity 3

Vapor Pressure and Surface Tension 5

Freezing Point of Solutions 6

Principles of St a b i l i z a t i o n .' 7

S o i l Tests

Mechanical Analysis 9

P l a s t i c i t y Teats 10

Function of Calcium Chloride 11

Construction 19

Maintenance 23

Cost 25

Frost Heaving 27

Summary 29

Future Research. 30

Appendix

Classified Subject Index 34

Author Index 35

Bibliography 37

FOREWORD

This i s the report of a special investigation to evaluate the use

of calcium chloride i n granular road s t a b i l i z a t i o n .

The project was sponsored and directed by a special subcommittee

of the Committee on Granular S t a b i l i z a t i o n with the cooperation and support

of the Calcium Chloride Association.

The investigation and report were made by Dr. F. L. Cuthbert, on

leave firom Princeton University and consisted of a c r i t i c a l analysis of

available l i t e r a t u r e . Or. Cuthbert has u t i l i z e d his background i n s o i l

science and his experience i n a n a l y t i c a l work to study the factors of the

problem i n an i n q j a r t i a l and objective manner.

An important feature of t h i s work i s the annotated bibliography.

I n addition t o arrangement of the major divisions of the problem i n t o a

c l a s s i f i e d subject index, a l l of the references are l i s t e d chronologically

with a b r i e f statement of the content following each reference. There i s

also an author index.

VI

USE OF CALCIUM CHLORIDE IK GRANUUR STABILIZATION OF ROADS

By F. L. Cuthbert, Ph. D.

The following worit i s a c r i t i c a l review and analysis of available

li t e r a t u r i s on the use of calcium chloride i n granular s t a b i l i z a t i o n of roads.

The project was undertaken f o r the purpose of gathering together the sum

t o t a l of the knowledge on the subject so that i t would be more readily a v a i l ­

able f o r use ajod could serve as a springboard f o r further research.

Granular s t a b i l i z a t i o n , while a r e l a t i v e l y new term, can be traced

back to C. M. Strahan's work i n Georgia, published i n 1929 ( 1 ) . ^ I n t h i s r e -

port Dr. Strahan pointed out the importance of proper gradation of the con­

stitu e n t fractions of clay, s i l t , sand, and gravel i n the performance of

the road. He also elaborated upon the function of each of the materials i n

contributing t o the s t a b i l i t y of the road. This* work naturally focussed the

attention of highway engineers and s o i l s men upon the p o s s i b i l i t i e s of pre­

paring stable, low cost roads by the manipulation of the clay, s i l t , sand

and gravel content.

The use of calcium chloride as an admixture did not enter the pic­

ture u n t i l a few years l a t e r , Eilthough i t had been used f o r some time as a

dust p a l l i a t i v e on d i r t and gravel roads. I n 1932, an investigation by the

Highway Research Board on "The Use of Calcium Chloride as a Dust P a l l i a t i v e "

(6) brought out the f a c t that calcium chloride not only acted as a dust pal ­

l i a t i v e but also tended t o maintain a moisture content i n the road which had

a be n e f i c i a l effect on- the s t a b i l i t y of the road I t s e l f . Colllngs and

71 - Figures i n parentheses refer t o the bibliography.

r

2. Stewart (21) presciited i n 1934 the f i r s t r e s i i l t s of track tests I n which d i f ­ferent sections of road were constructed with d i f f e r e n t materials and sub­jected t o t r a f f i c and weathering t e s t s . They showed that compaction was f a ­c i l i t a t e d by the use of calcium chloride. Their report also included data on d i f f e r e n t types o f road sections.

From that time on the use of calcium chloride as an admixture i n

granular stabilized roads rapidly Increased u n t i l such road projects were

being constructed i n many states. A resume of the status was published i n

1933 (7). Numerous research investigations by various groups and i n d i v i d u ­

als quickly established information concerning construction procedures and

theories were advanced i n regard t o the part plajred by calcium chloride i n

aff e c t i n g s t a b i l i t y .

The main purpose of t h i s report i s t o review and analyze these

papers.

While the references studied were r e s t r i c t e d to those on the use of

calcium chloride i n s t a b i l i z a t i o n i t i s desirable to mention b r i e f l y various

other uses i n highway construction. These are:

1. Use as a dust p a l l i a t i v e . 2. Use as an aid i n the pi^vention of freezing of subgrades. 3. As an aid i n decreasing the damage to gravel roads due

to f r o s t action. /«.« I n the treatment of sand and similar materials used as

skidding preventatives on i c y pavements. 5. Use i n the acceleration of early hardening of cement and

as a curing agent.

Manufacture and Properties of Calcium Chloride

Calcium chloride, chemical formula CaCl2i i s a white, highly d e l i ­

quescent s a l t . The following information regarding i t s occurrence, manu­

facture, physical and chemical properties has been taken mainly from two

very detailed reports; "Calcium Chloride" (22), and "The Story of Calcium

Chloride as a Road Binder" (100).

3.

Manufacture and Occurrence - Calcium chloride does not occur nat u r a l l y ex­cept i n solution i n s a l t brines and mineral springs, and as a constituent i n a few minerals of no commercial importance i n t h i s country. The most I n ^ r t e i n t sources are natural brines and by-products produced i n the mzmu-facture of ammonia or ammonium carbonate, carbon dioxide from marble, potassium chlorate, and sodium carbonate by the Solvay Process. I t i s i n ­teresting to note that the chemicad was considered a waste product and d i f ­f i c u l t t o dispose of u n t i l research and developments led t o i t s use i n several varied f i e l d s .

Properties - Deliquescence and Hygroscopicity - Deliquescence i s the a b i l ­

i t y o f a material t o absorb moisture from the a i r and thus to be dissolved

and become l i q u i d . Hygroscopicity i s the a b i l i t y to absorb and ret a i n mois­

ture without necessarily becoming l i q u i d . Calcium chloride possesses these

two characteristics t o a marked degree as shown i n Table I .

TABLE 1* The extent t o iriiich the chemical I J K I . l g U K S C E N ' C K exhibits these properties under

( l . t iwvst Relat ive I lun i id i ty and Te inpcr . t -t „ rc at « h , c h j : a l c j u m Chlor ide natural condlUons i s governed by

U d a t i v f Humid i ty T e m p . deg. K. . , j . ^ j ^ ^ ^ 100 tesqperature and humidity I n such a

M) 74 ^ manner that the higher the r e l a t i v e "̂ humidity of the a i r the more w i l l

H Y t . K O M O I M C I T Y

(I ' . .ni id!, of W a t e r T a k e n ui> by O n e be absorbed a t a constant tenpera-Poi ind tif 1-l.ike C'alciiiin Chlor ide

at D i i i e ren t Humidi t ies. ) ture; and the higher the humidity, Kel. it ive T e i n p . I.b-.. W a t e r T a k e n i lui indit> deK. I". up by 1 lb. C a C l the lower the teji?)erature at lAlch

3t, 77 1.0 (lU 77 1.6 the chemical w i l l dissolve. 70 77 2.0 80 77 2 8 85 77 3.5 W 77 5.0 «<5 77 8 4

VAPOR PRESSURES OF CALCIUM CHLORIDE SOLUTIONS EXPLANATIONS OF CURVES

t WPOR PHtSSUnC OrmrCR l$ih*n by thtuiftntcffonofttm-ptralvn ciintt i»MJtOXtaMmeMondfcrJlnair Tha iMiporprtttvrt of walvrafeSTia 30.4mm.

ZVAPOR PRCSSURCS or CALCIUMCHLOmOC SOLUTIONS of Mrwu) ttrtnglhs tt di/fertnt ttmparaturea an ahotin by M« hfyy lints.

Thus atSSTa solution aniainhg eox calcium chloride (TStCoC/,) has avapor prtssi^o of 26.8mia a/tdono corrtalningSOX has a vapor pros»ur» of IZenm. As notsd abovo, water at this temperature has a vapor praaaura of 30.4m m.

3iACi.Ar/I^C HUUIOITY CURVCS show vapor pressures of water attach temperature and humidity represented by their Inftrstctloni with temperature curves

Thus at 35'rtmdSOX relative humidity the vapor pressure of water In the air ii ISZmm,iM SOX of 3Q 4 mm Under these con­ditions of temperature and vapor pressure, calcium chloride or any of its solutions having a vapor pressure lower than ISJmm will absorb water sufficient to make a solution eantemmg 46%ealcli/m chlorhie(f8XCaC{\which is the strength havingavapor pressure of/S2mm A weaker solution tt)on46%at this tem­perature and humidity will have a higher vapor pressure thanISZ mm,hineemlllhsewalertothealruntHthls sfrtngth is reachtd.

< SATURATED SOLUTION CURVE Is dettrmlntd by the fact that whenthe humidity and temperature conditions fall to the rightaflttvaporpreaaurea are so low thateolelum chloride solution wll be eeneentrvted to cryatallint or eolid fbrm.Svch erystalllrte material will reabsorb moisture as soon as the humidify and temperature conditions change to those shown

\ \ \ \ \ \ ^ ^ ^ ' ' ^ aaturated solution curve.

Yo "ealekjmOilorldt'fiBX Ce^ln soliihen

Figure 1 ,

\laforpmture atiinulUHriUifmvnm

Cantorf niathn InmUity

SalmM Solution Cum

5. Vapor Pressure and Surface Tension - Vapor pressure i s a dire c t measxire of

the speed of evaporation and i s d i r e c t l y affected by temperature and the

strength or concentration of the materitd. While calcium chloride i t s e l f

does not evaporate, the water i n a solution containing calcium chloride

w i l l , although at a slower rate than pure water. This means tha t s o i l s

containing calcium chloride i n solution w i l l remain moist longer than i f

the chloride was not present. Figure 1 shows the vapor pressure of va­

rious strengths of calcium chloride solutions.

Surface tension i s also related t o the rate of evaporation i n such

a manner that a solution possessing high surface tension w i l l tend to va­

porize less rapidly than one having low surface tension, with other factors

constant.

Figure 2 shows the increase i n

siirfaee tension effected by add-

ing calcium chloride to water.

This indicates, f o r example,

that a 25 per cent solution of

calcium chloride has a surface

tension about 14.6 per cent

higher than that of pure water. PiM amr tmiciuM emtomtpt tetmoM

Figure 2 . Snrface Tension of Calcium Chloride Solutions at 77°F.

6.

•1

^1

—X \

\ V

/

\ / / \ /

etecH TiMt

Figure 3. ngurionsmp or IV»POMTIOM a^rtsor MoisTum rMM TkiiTio 4 uKTiuno ious t THi uncT or TMt HtL0TIVt HUMIDITY OH TMt HVGMiCOPIC PROPtRTY 0/THt CttCIOM CMLORIDt TRIHTIO SV/l

• otn tun notiiuMct vmwrntr utumtm tt*»o • f»mr m. mi

Figure 3 shows the effect

of these properties on re­

ducing evaporation of

moisture from calcium chlo­

ride treated s o i l s i n com­

parison t o untreated s o i l s .

I f dry s o i l i s mixed with

water to any fixed percent­

age of moisture, that water

w i l l proceed t o evaporate

u n t i l the s o i l i s again as

dry as i t was before; but i f mixed with an equal quantity of calcium chloride

solution which i s i n equilibrium as* t o temperature and r e l a t i v e humidity, i t

w i l l stay continuously as moist as the calcium chloride solution w i l l render

that s o i l .

Freezing Point - The freezing points or freezing temperatures of calcium

chloride solutions vary according t o the strength or concentration of the so­

l u t i o n . Comparatively small percentages are effective i n i*educing the freez­

ing point below that of water as shown i n Table 2. This property, although TABLE 2.

Effect of Calcium Chloride on Freezing of Water Chemical, % of Weight

of Water 5

10 15 20 25 30 35 UD 45 50

Freezing Point Defi»

28 23 21 10 -2

-18 -30 -46 -55 -60

i t has no d i r e c t bearing

on the use of calcium

chloride i n s t a b i l i z a t i o n

i s important i n i t s use as

an aid i n the prevention

of detrimental iroat heav­

in g .

7 .

Principles of S t a b i l i z a t i o n

S o i l s t a b i l i z a t i o n , as defined by Hogentogler (140) i s "the process

of giving natural s o i l s enough abrasive resistance and shear strength t o ac­

commodate t r a f f i c or loads under prevalent weather conditions, without d e t i l -

mental deformation." He goes on to say, "The methods en^loyed Include the

use of admixtures, compaction, and densiflcation by specific technical theory

and laboratory control. Optimum water content i s fundamental w i t h gradation.

Admixtures may be s o i l materisds, deliquescent chemicals, solutions of elec­

t r o l y t e s , soluble cementitlous chemicals, primes and neutralizers, and i n ­

soluble binders." A broader d e f i n i t i o n that i s ftequently used states, "A

stabilized road i s one that w i l l not flow l a t e r a l l y under a load " (139).

Three factors are fundamental t o s t a b i l i z a t i o n ; gradation, water

content, and compaction or densiflcation. A l l three of these are also i n ­

terdependent upon each other I n such a manner that they must be considered

together.

Del French (30) states that f o r s t a b i l i t y two types of resistance

are needed; the "sand-paper e f f e c t " produced by the i n t e r n a l f r i c t i o n of

the p a r t i c l e s of aggregate and the "fly-paper e f f e c t " produced by the

"stlckitlvaness" of the f i n e r materials l i k e clay. This i s effected by

gradation. Each of the components of a well-graded s o i l adds i t s own pe­

c u l i a r characteristics t o the s t a b i l i t y of the irtiole. Clay, due to i t s

cohesive properties when wet provides cohesion and acts somei^at as a ce­

ment between the larger particles of s i l t and sand which have no cohesive

properties. Also, clay« due t o . i t s mineral composition and crystallne

structure may be considered as the active ingredient, i n the sense that

i t s properties can be changed somewhat by chemical action (149) ( 7 0 ) .

S i l t provides pore f i l l e r and embedment f o r the sand grains and contrib-

8.

utes t o the i n t e r n a l f r i c t i o n of the vrtiole, another essential f o r s t a b i l i t y . Sand and gravel, usually of less than 1-in. maximum p a r t i c l e diameter, sup­ply the greatest amount of i n t e r n a l f r i c t i o n and affords a hard wearing course f o r the road (118).

As desciTlbed by Proctor (15) i t was discovered that compacted mix­

tures of such materials possess an optimum moisture content £uid a maximum

density f o r each degree of compactive e f f o r t used i n molding specimens,

" I f a given s o i l i n an ai r - d r y condition i s placed i n a container and sub­

mitted to a d e f i n i t e conqpactive e f f o r t , a certain density (usually measured

i n pounds per cubic foot) w i l l be obtained. I f a small percentage of water

i s added and the s o i l i s again coiqiacted with the same amount of e f f o r t , a

greater density i s obtained. By repeating t h i s procedure, using the same

con9)active e f f o r t , but Increasing the moisture each time, a moisture content

w i l l be found f o r which the density of the s o i l i s a maximum. The moisture

i n the s o i l at maximum density i s called the optimum moisture content f o r

t h i s compactive e f f o r t . I f the test i s repeated, using a greater compactive

e f f o r t , a higher maximum density w i l l be obttdned at a lower optimum mois­

ture content. On the other hand, i f a smaller compactive e f f o r t i s used, a

lower maximum density w i l l be obtained at a higher optimum moisture content.

For a given s o i l , therefore, there are as many 'maximiim densities' and 'op­

timum moistures' as there are con^ctlve e f f o r t s used " (194). Hogentogler

and Kelley (101) state "that a l l s o i l Mxtures suitable f o r road use are

stable at some water content", and "water i n stable roads i s more adhesive

than free water and s t a b i l i t y depends upon the thickness of the absorbed

moisture f i l m s , and the p r i n c i p a l aims of s t a b i l i z a t i o n are to make the

s o i l as dense as possible and t o prevent the thickness of the moisture films

from changing". Thus the relationships of water content and density are

9.

clearly shown. Burmister (122), Shaw (184), and Uaddlson (188) have con­

ducted experiments showing the effect of gradation on density. Uaddison's

results showed that there was a s l i g h t reduction i n the dry density of the

s o i l mortar with crushed stone contents up t o 25 per cent and with larger

amounts the dry density of the s o i l mortar (pa r t i c l e s less than 2 mm. i n

diameter) was considerably reduced and that the optimum moisture content

Increased with increasing stone content.

Use i s made of these principles of s t a b i l i z a t i o n i n working toward

two objectives; the most stable combination of the available materials, and

as great a degree of permanence of that s t a b i l i t y as i s possible by means

of mechanical consolidation and the use of admixtures (58).

S o i l Tests

The Division of Physical Research of the Public Roads Administra­

t i o n has done a great deal i n investigating, slnplif^dng and standardizing

a few s o i l tests which aid i n determining the s u i t a b i l i t y of earth materials

f o r s t a b i l i z a t i o n and i n the construction of s t a b i l i z e d roads. Limits have

been defined w i t h i n which the s o i l tests or s o i l constants most f a l l f o r op­

timum s t a b i l i t y (118). These tests and the functions of each have been des­

cribed i n numerous papers and i t i s not purposed to describe them i n d e t a i l

i n t h i s work but merely t o mention them and the part played by each (21)

(186). "Wartime Road Problems", No. 5 on "GSranular Stabilized Roads" (186)

published by the Highway Research Board I n 1943 piresents an excellent des­

c r i p t i o n of the s o i l tests most commonly used and the following i s taken

mainly from that source.

Mechanical Analysis - The gradation of the p a r t i c l e s of a s o i l i s determined

by sieve analysis. Recommended l i m i t s , based on the Specifications of

10.

A.A.S.H.O. and A.S.T.U., n l t h i n which the gradation should f a l l f o r various

types of construction, cure given i n Wartime Problems No. 5', on Granular Sta­

b i l i z e d Roads (186). Figure 4 shows gradation l i m i t s f o r a base course mix­

ture (118).

P l a s t i c i t y Tests - These tests are indicative of the a c t i v i t y of the clay

portion of a s o i l , and are made only on that material passing a No. AO sieve,

irtiich i s the f r a c t i o n that supplies the greatest amount of cohesion t o a

s o i l . The p l a s t i c l i m i t i s the moisture content at ithLch the s o i l passes

from the semi-solid state to the p l a s t i c state; and the l i q u i d l i m i t i s the

moisture content at which a s o i l passes from the pla s t i c state t o a l i q u i d

state and begins to flow. The p l a s t i c i t y index (P. 1.) i s the difference

between the l i q u i d and p l a s t i c l i m i t s and i s an index of the cohesive power

of the material and also of i t s f l o w a b i l l t y under pressure. A low p l a s t i c i t y

index i n d l -

r>/7e ̂9gre9o(e

cates low

coheslveness

and a high

Index a tend­

ency t o I n ­

s t a b i l i t y

when wet.

Figure 4. Stablllzatton Chart for l-ln. Mazimum Size Aggregate for Base Course

1 11.

Function of Calcium Chloride

From the foregoing Principles of s t a b i l i z a t i o n i t i s noted that water

plays a prominent rol e i n s t a b i l i z a t i o n . F i r s t , i t i s necessary to make the

clay cohesive and second, i t provides the medium by which maximum density can

be obtained by compaction. An excellent review of the influence of i n t e r n a l

f t l e t i o n and cohesion upon the s t a b i l i t y of soils i s given i n the General

Theory of S o i l S t a b i l i z a t i o n , Part I , of the Progress Report of the Highway

Research Board Project Committee on Stabilized S o i l Road Surfaces (58). Data

are given which show that a decrease i n cohesion of a s o i l may r e s u l t i n a

decrease i n the supporting value of that s o i l from about 12,000 l b . per sq.

f t . t o less than AOO l b . per sq. f t . This indicates the importance of main-Nil

t a i n i n g the proper moisture content i n s t a b i l i z e d s o i l s .

P r a c t i c a l l y a l l of the water added to a clay, s i l t , sand, and gravel

mixture w i l l be p r e f e r e n t i a l l y adsorbed by the clay f r a c t i o n (82), which i s ^ _ ^ ' ^ ' * ^

irtiy t h i s f r a c t i o n i s sometimes termed the "active f r a c t i o n " (86). I t i s also

known that clays are made up f o r the most part of very small p l a t e - l i k e min­

erals called clay-minerals (1A9) and that these minerals have peculiar water

adsorbent properties. Due t o the electro-chonical a c t i v i t y of the day-

mineral, water i s adsorbed i n such a fashion that i t actually exists i n d i f ­

ferent forms, from the surface of the clay-mineral p a r t i c l e outward t h r o u ^

the thickness of the water f i l m (81). nie molecular layer of water closest

to the surface of the p a r t i c l e i s adsorbed so strongly that i t i s more l i k e

a s o l i d than l i q u i d water. As the water layer or f i l m thickens t h i s s o l i d

character i s l o s t due t o the decreased strength of adsorption as the distance

from the clay-mineral p a r t i c l e increases. Consequently, the outer layers

are more l i k e the water that we commonly think of. The Public Roads Adadjiis-

t r a t i o n ' s investigations have shown that the l i n e of demarcation between

12.

" s o l i d " water and "free" water i s r e l a t i v e l y sharp (70). Figure 5 i s a

sketch of these d i f f e r e n t phases of water sutrounding a clayHnineral p a r t i ­

cle. Rapp and Mizroch show that the property or a b i l i t y of clay t o adsorb

water may vazy considerably with

GMV1TATI0NM. OA CAPILLARr

W T t R

COHESIVE WATER

SOLtOIFlEO WATER

COLLOlO

FREE WATER

ADSORBED OR HYORATEO

WATER

PHYSICAL ELETRO-CHEMKAL

CHARACTER o r SOIL UOISTURE

Figure 5. Clay particles in suspension

the clay due t o the f a c t that i t

may be coiqx>sed of d i f f e r e n t

types of day-minerals (149)*

Thus i t can be seen that i t i s

possible f o r these moisture films

to exert tremendous binding forces

between the clay pa r t i c l e s and

that any treatment designed t o ef­

f e c t changes i n the nature of

these films i s bound t o have great

influence i n either strengthening

or weaking t h i s bond.

These moisture films must play a part i n co]q>action and may be c r i t ­

i c a l from the standpoint o'f obtaining and maintaining s t a b i l i t y . The tests

described by Proctor (15) are i n a fashion, a measure of the a b i l i t y of the

clay t o adsorb molstiu'e. Uoisture-density curves, as determined by the

Proctor method show that maylimim density i s obtained over a r e l a t i v e l y nar­

row range of moisture content with s o i l s containing small percentages of

clay and that with either greater or lesser amounts of water the density de­

creases, when the conpactive e f f o r t i s kept the seune. Figure 6 shows a

t y p i c a l moisture-density curve. This aarrow moisture range i s further i n ­

dication of the importance of moisture control i n s t a b i l i z a t i o n and of the

p o s s i b i l i t y of obtaining improvements i n s t a b i l i z a t i o n through the manlpu-

13.

l a t i o n of the clay-water relationships either by chemical or physical meth­

ods or combinations of both.

102

| . 0 .

3 ' 0 0

8 „ i

i 7 \ !

y / 1 —

I s

i f

30 20 22 24 26 2 » MOISTURE CONTCHT - PERCENT

FiooBE 6 . — E F F E C T OF V A R I A T I O N S I N M O I S T U B B C O N T E N T U P O N T H E D E N B I T T A N D S T A B I L I T Y OF A S O I L .

Calcium chloride,

nhen used i n granu­

l a r s t a b i l i z a t i o n ,

due t o i t s hygro­

scopic and d e l i ­

quescent properties

w i l l a t t r a c t mois­

ture and dissolve

so t h a t a calcium

chloride solution

i s formed. There­

fo r e , when t h i s

chemical i s used we

no longer have a

clay-water r e l a t i o n ­

ship t o consider but a clay-calcium chloride solution relationship and the

c r i t i c a l problem i s t o determine how these two relationships d i f f e r .

I n order f o r a calcium chloride solution t o have any ef f e c t on s t a b i l ­

i s a t i o n i t i s necessary f o r i t t o move throughout the material being treated

and s t a b i l i s e d . The ef f i c i e n c y of the movement of the calcium chloride solu­

t i o n , whether applied s u p e r f i c i a l l y or mixed i n t e g r a l l y depends upon a nuisber

of factors. Slesser (185) reported an extensive laboratory and f i e l d study

i^)on the movement of calcium chloride i n s o i l irtiich points out that the most

isQwrtant variables a f f e c t i n g movement are; evaporation, s o i l texture, peiv

colating water, s o i l cover, and temperature. He found that the calcium chlo­

ride solution migrated downward by leaching from the surface and that under

conditions of evaporation i t was not found on the surface but that i t did

have a tendency t o be concentrated i n the upper layers, so that any benefic-'

i a l e f f e c t which might occur from i t s presence would be repeti t i o u s . Since

the chemical did not c r y s t a l l i z e on the surface during evaporation very

l i t t l e was l o s t by nm-off. The pennanence of the calcium chloride solution

was found to be d i r e c t l y affected by the type of s o i l ; a sandy-clay s o i l ap­

parently holding the chemical better than others. One of the f i n a l conclu--^

sions of t h i s excellent piece of work was that the chemical should be mixed

i n t e g r a l l y with the s o i l f o r best re s u l t s .

This work showed that movement of calcium chloidde does take place-

when used as an admixture i n st a b i l i z e d soils and when i t i s applied i n the

s o l i d form. Of course, i f applied i n a brine or pre-mixed solution the same

w i l l hold true. I n view of t h i s phenomenon we can see that we are not so

p a r t i c u l a r l y concerned with clay-water relationships i n cedcium chloride sta­

b i l i z e d roads as we are with clay-calcium chloride relationships.

The absolute differences between the clay-water and clay-calcium ,

chloride relationships are not d e f i n i t e l y known. There i s some evidence to •

indicate that the increased surface tension of the csilcium chloride solution

may make the films around the clay particles stronger and thus increase the ,

cohesiveness or strength of the bonds between the sand grains (81). I t i s

also very l i k e l y that the phenomenon of base-exchange plays some part (70)

(1A9)« Base-exchange i s defined as the substitution of a base f o r another

base or hydrogen i n the s o i l . An exaiq)le of t h i s reaction i s given by ,,

Rapp and Mizroch (149); "A sample of s o i l that showed an acid reaction was

placed i n a funnel and neutral potassium chloride was leached through the

15.

s o i l . The leachate was tested and found t o be acid; on analysis the s o i l was found to contain more potassium than the o r i g i n a l s o i l . " The reaction i s w r i t t e n as follows: "Hydrogen clay -•• potassium chloride potassium clay + hydrochloric acid." This-process i s reversible and follows w e l l defined chemical laws. Hogentogler and V / i l l i s (70) show that the physicsuL properties of calcium clay are d i f f e r e n t than those of hydrogen clay and potassium clay. However, the exact determination of t h i s difference i n a sta b i l i z e d road and how i t affects the s t a b i l i t y of the road remains f o r further investigation.

As stated previously the p r i n c i p a l aims of s t a b i l i z a t i o n are to

make the s o i l as dense as possible and t o prevent the thickness of the

moisture f i l m s from changing. Elleman (139) says, "Stabilization hinges

on the bonding action of these f i l m s . " Evans (95) states, "Calcium chlo­

rid e operates t o conserve water i n s o i l by reducing the rate of evaporation

i n dry spells and by absorbing water from the atmosphere under conditions of

high humidity." Hogentogler, J r . (9) suggests that moisture f i l m cohesion

furnished by csdcium chloride i s greater and lasts longer than that furnish­

ed by water alone. This f a c t i s of great impoirtance i n promoting s t a b i l i t y

since i t has been shown that one of the main requisites of s t a b i l i z a t i o n i s

not only t o supply the correct amount of water during construction so that

maximum density can be attained by compaction but also t o maintain the

proper moisture f i l m thickness to insure s t a b i l i t y .

The o v e r a l l resrilts of incorporating calcium chloride i n granular

s t a b i l i z a t i o n have been determined by several laboratory and f i e l d i n v e s t i ­

gations by various groups. Hogentogler and W i l l i s (70) state, "Treatment

with either calcium chloride or soditim chloride (common s a l t ) effects a de­

crease i n the volume change and an increase i n the density and s t a b i l i t y of

16.

graded road mixtures; the eajicium chloride does t h i s through e l e c t r o l y t i c

and deliquescent properties, and the sodium chloride through e l e c t r o l y t i c

and c r y s t a l l i n e properties. Generally the surfaces^treated with sodium

chloride are harder with a dryer appearance and s l i g h t l y more dust, than

the surfaces treated with calcium chloride." They also say, "Because so­

lutions of ccddum chloride and sodium chloride have lower vapor pressures

than water, the evaporation of moisture from s o i l mixtures wetted with these

s a l t solutions i s d e f i n i t e l y slower than from similar mixtures moistened

with water. These salts i n a st a b i l i z e d road mixture therefore tend to con­

serve i t s moisture." The tendency of calcium chloride treated soils to

maintain t h e i r moisture content to a greater degree than untreated s o i l s was

w e l l i l l u s t r a t e d by Burggraf ( 6 ) . Figure 7, from that work, shows that the •

tendency toward loss by evapora-

4tt

y

Trti tti

" 1 I i — i 7 I

\ \ e/ay»

Figure 7. Relation of Evaporation Losses from Treated and Untreated Soli Aggregate Road Mixtures. (Composite Data on Labora­tory Tests from Three States, Highway Re­search Board Proceedings, Vol. 12, Part I I , 1932.)

t l o n i s greatly reduced when

so i l s are treated with calcium

chloride.

The effect of calcium chlo­

ride on density of s o i l was i l ­

lustrated by an investigation

made by Hogentogler, J r . (81).

He showed that by using the

same compactive e f f o r t , 135 l b .

per sq. i n . , an untreated s o i l

.had an optimum moisture' content

of 41.2 per cent comptired to

33.0 per cent f o r the same s o i l treated with calcium chloride; also that t o

have the same optimum moisture content of 33 per cent, the untreated s o i l

17.

required a pressure of 1,100 l b . per sq. i n . whereas the treated s o i l requir­

ed only 135 l b . per sq. i n . These data also indicated t h a t , at the same

pressure of 300 l b . per sq. i n . , the untreated s o i l attained a density of

104.4 l b . per cu. f t . as compared with 114.5 l b . per cu. f t . f o r the treated

s o i l . Other tests indicated that under the same conqjactive e f f o r t the

weight of untreated and treated calcium chloride s o i l s was 97 and 108 l b . per

cu. f t . respectively, an increase of 11 per cent i n favor of the treated s o i l .

An investigation by W i l l i s and Carpenter (136) involving the use of

an outdoor c i r c u l a r track to determine the effects of calcium chloride and

other chemicals on nonplastic granular mixtures under controlled t r a f f i c and

moisture conditions showed that : 1. The use of calcium chloride eaqiedited

coii?)action and reduced r a v e l l i n g while the base courses were carrying t r a f f i c

p r i o r to the construction of the bitiuninous wearing courses, and 2. mixtures

irtiich contained calcium chloride during the i n i t i a l compaction period reach­

ed a condition considered suitable for s t a r t i n g the test at somewhat less

than one-third the wheel t r i p s required t o produce a similar condition i n

tracks vMch did not contain calcium chloride. I n other words, the use of

calcium chloride f a c i l i t a t e d coiqpaction so that the desired condition was

obtained with much less compactive e f f o r t .

Belcher (161) reported the results of a very ca r e f u l l y controlled

investigation i n which a t e s t road was constructed coursed of sections con­

structed i n various manners. One of these sections was made up of 88.5 per

cent p i t - r u n gravel and 11.5 per cent s o i l plus 0.5 per cent calcium chlo­

ride incorporated i n the top 2 i n . and 0.51 l b . per sq. yd, added t o the

surface. Inasmuch as the road was not part of a regular highway system con­

t r o l l e d t r a f f i c was introduced t o simulate road conditions. The conclusions

state that the incorporation of calcium chloride w i l l materially decrease

18.

dusting and w i l l also increase the resistance of the mixture to r a v e l l i n g ;

ani that the chemical should be incorporated i n the mix when feasible since

surface applications are subject t o being washed o f f before they have an op-

poirtunity t o migrate i n t o the mix.

Blomquist (178) used an indoor c i r c u l a r track to study the effects

of using calcium chloride i n stabilized mixtures. The conclusions reached

i n his study as they pertained to the use of calcium chloride were:

1. The general behavior of sections with calcium chloride admixtures were

superior t o those with no calcium chloride added, "niese. sections were

surface bound and t h i s reduced r a v e l l i n g .

2. Calcium chloride expedited compaction i n a l l sections i n which i t was

incorporated.

3. Binding of aggregate securely i n place w i t h stable s o i l mixtures and

calcium chloride eliminates most of the destruction and loss of road

material due to the action of t r a f f i c .

Burggraf designed an apparatus to te s t the resistance of the struc­

t u r a l conqjonents of a road t o latered displacement which gives the s t a b i l i t y

resistance of the section tested i n l b . per sq. i n . (130) (137) (151). He

concluded from use of t h i s apparatus that; stabilized mixtures containing

calcium chloride a t t a i n the same degree of compaction with less than h a l f as

much r o l l i n g as untreated mixtures, that the inherent s t a b i l i t y i n a calcium

chloride stabilized road increases during the seasoning or "drying out" per­

i o d , and that i t i s highly ijqwrtant to maintain stabilized roads as open

surfaces u n t i l f u l l s t a b i l i t y i s obtained, since 90 per cent of the ultimate

s t a b i l i t y develops during the seasoning period, r o l l e r compaction accounting

f o r only 10 per cent.

19. Swinton (126) planned and carried out an investigation to determine

the loss of gravel from stabilized road sections. The results of t h i s i n ­vestigation showed that the loss i n gravel was decreased from 100 per cent fo r an ordinary untreated gravel road to 37 per cent f o r a calcium chloride stabilized road.

A detailed study of calclvim chloride and a l l phases of I t s use i n

the s t a b i l i z a t i o n of roads was made by Collings and Stewart i n 1934 (21).

This study i s perhaps more con?)lete than any other made. Among the vairLous

items ^ u d l e d was the ef f e c t of using calcium chloride i n s t a b i l i z a t i o n as

determined by the use of a ca r e f u l l y constructed and controlled indoor road.

The construction of the road Involved a humidity controller and a " r a i n ­

maker." An 8700-lb. gross weight truck was run back and f o r t h i n the same

path over the test sections, both during and af t e r a "ra i n " t o determine the

re l a t i v e s t a b i l i t y . By alternately wetting and drying test sections, and

san^ling they showed that considerable movement downward and upward of c a l ­

cium chloride resulted when subjected respectively t o wetting and drying

t e s t s . S t a b i l i t y tests on treated and untreated sections showed that the

use of calcium chloride resulted i n a f i r m l y , bound, dustless surface. This

report also contains an excellent description of the preparation or con­

struction of calcium chloride stabilized roads, and data on t h e i r costs and

maintenance.

Construction

Methods of construction f o r building calcium chloride stabilized roads

are perhaps best introduced by Blessing and Smith's (24) statements on the use

of t h i s type of construction. They state, "The usual applications of s t a b i l ­

i z a t i o n are:

20.

1. "For binding loose stone or gravel.

2. "For adjusting properties and proportions of s o i l fines i n ex­

i s t i n g wearing courses by adding needed binder or aggregate

and then scarifying to a depth of 3 i n . or more and mixing

thoroughly.

3. "For improving wearing properties and hastening consolida­

t i o n of resurfacing material and of new construction on

gravel, stone, or slag roads.

4. "For increasing the supporting value of grades before con-

stiniction of st a b i l i z e d wearing courses, done by addition

o f clay t o sand grades or of sand or low cost stone screen­

ings t o clay roads."

Calcium ehloilde has been used mainly i n three types of constiruction;

(128, 139, 155) surface consolidation, s t a b i l i z a t i o n and dust laying. A l l

three of these are r e a l l y a phase of s t a b i l i z a t i o n . U i l l e r (128) says that ;

" S t a b i l i z a t i o n involves the adjustment of s o i l con^xjsition by standard meth­

ods so that i t w i l l consist of a dense wearing course or base composed of a

designed mixture of graded aggregate, binder s o i l , and calcium chloride. Sur­

face consolidation involves the use of gravel or stone already i n place by

adding binder s o i l t o f i l l the voids and to furnish the cohesive constituent

and calcium chloride t o maintain the proper moisture content. Dust laying

involves the addition of calcium chloride t o stone or clay surfaces t o sup­

p l y moisture,"

Surface consolidation i s also considered by some t o be a form of

in^rovement i n maintenance of gravel roads (116, 182). Knight (91) con­

siders surface consolidation t o be a form of stage construction. He states:

21.

"In the past, the stages of construction were; d i r t surfaces, gravel, black top, and f i n a l l y a hard surface. Now the gravel surface i t s e l f can be b u i l t i n stages by a method called surface consolidation." I n another report ( 5 3 ) he says, " A l l maintenance s h a l l be considered as progressive steps towards the gpal of a st a b i l i z e d road." The same term i s applied when calcium chlo­ride i s used to consolidate limestone or similar surfaces. Stegner (182) re­ports that t h i s usage results i n more durable roads, reduces maintenance blading and upkeep costs, and increases the safety factor through dust re­duction.

S t a b i l i z a t i o n , as the term i s used by U i l l e r (128) implies the con­

struction of a road designed £roBL the beginning to be stabilized throughout,

from the subgrade to the wearing course. However, the same principles and

methods of construction are used i n a l l layers f o r i n low-cost surfaces such

as stabilized roads i t i s d i f f i c u l t to demarcate the roadway structxure and

i t s foundation, as the only d i s t i n c t i o n appears to be i n the types and sources

of materials used ( 6 3 ) .

The construction methods used are largely governed by l o c a l condi­

ti o n s ; including type of equipment and available labor, source of binder

s o i l and aggregate (frequently material i s obtained from the shoulders that

can be u t i l i z e d e f f i c i e n t l y ) and other conditions which necessarily vary

from one l o c a l i t y t o another.

Numerous references are l i s t e d i n the bibliography that describe i n

d e t a i l the methods of construction used i n various stabilized road projects,

and these can be consulted f o r reference. However, a study of these reports

brings f o r t h a few items worthy of special mention.

Careful observation and study of a number of calcivim chloride s t a b i ­

l i z e d roads by Burggraf ( 5 7 ) revealed that the amount and type of crown i s

22.

p a r t i c u l a r l y iiq>ortant. The recommended crown i s a modified "A" type, of at least ^ i n . per l i n e a l foot and never less than 3/8 i n .

B. C. Tiney (106) reports that the trend of design of stabilized

mixtures has been to reduce the proportion of binder s o i l and thereby lower

the p l a s t i c i t y index of the mixtiure. VAien constructing stabilized bases f o r

bituminous surfaces the P. I . ( P l a s t i c i t y Index) should be lower than when

constructing f o r t r a f f i c wear. The general specification requirements are

f o r a P. I . of not more than 3 or 6, depending on the gradation, f o r base

courses, and a p l a s t i c i t y of not less than U or more than 9 f o r surface

courses. (118). There i s an increase i n the plant production of mixes, i n

the use of multiple irtieel pneumatic t i r e d r o l l e r s , and a greater enqjhasis

on obtaining the optimum moisture content f o r maximum density.

I n order to u t i l i z e available l o c a l materials, i n d i v i d u a l state re­

quirements are generally el a s t i c (107, 112).

A tremendous growth has taken place i n the number of State highway

department s o i l laboratories equipped f o r conducting tests necessary f o r

the construction of stabilized roads. I n 1932 a survey indicated that 13

States and the D i s t r i c t of Columbia had s o i l laboratories. Seven years

l a t e r 41 highway departments were equipped.

Many reports recommend that the calcium chloride be mixed integrcdiy

with the other materials rather than merely applied on the surface (39, 95),

This practice has undoubtedly lead to the increase i n the use of plant nixed

or prepared materials. Excellent renews covering the equipment needed, de­

sign of plant, and types of mixes have been prepared by Stewart (104) and

Olmstead (152, 153) among others. The advantages claimed f o r t h i s type of

preparation of stabilized mixes are:

23.

1. Better control of proportions of ingredients and consequently more u n i ­form mixes.

2. T r a f f i c i s not t i e d up f o r long periods of time.

3. Weather i s not a decided factor.

4. I t makes stabilized construction available to those who may not have a l l

the necessary equipment f o r road mixing.

5. Producers of aggregate may u t i l i z e overburden which o r d i n a r i l y would have

to be stripped thus adding t o the t o t a l expense.

Several instances i n which u t i l i z a t i o n of plant mixed materials has

found p a r t i c u l a r application i s i n the construction of streets and the s t a b i ­

l i z a t i o n of shoulders, although both plant mix and road mixed materials may

be used. The entire shoulder i s excavated to a depth of 4 t o 6 i n . , 2^ t o

3 f t . wide, and the pre-mixed stabilised mixture then compacted i n t o t h i s

excavation (71). E3q>eriences i n iriiich c i t y streets have been b u i l t of

stabilized materials indicate that the general construction procedures used

are similar to those i n road construction (69, 73, 88, 99, 129, 131). I n

the majority of cases the stabilized street a f t e r being coiq>acted by t r a f f i c

has been covered with a l i g h t bituminous mat (73, 109, 131). These re­

ports of the use of calcium chloride s t a b i l i z a t i o n i n the construction of

c i t y streets a l l express satisfactory r e s u l t s . A central mixing plant i s

suggested t o prepare a calcium chloride stabilized mix containing gravel,

crushed stone or slag with enough sand or fines to f i l l the voids and enough

binder s o i l and water to supply cohesion, and calcium chloride at the rat e

of about 18 l b . per cu. yd.

Uaintenance

The type and amount of maintenance required to keep calcium chloride

st a b i l i z e d roads i n good condition throughout the year varies from one l o -

24.

c a l i t y to another dependent upon the amount of t r a f f i c , weather conditions, and l o c a l practice. There are unique characteristics of t h i s type of road that warrant specific mention i n regard t o maintenance.

There are three objectives t o f u l f i l l i n the maintenance of calcium

chloride stabilized surfaces; (1) t o provide smooth r i d i n g surfaces, (2) to

keep wearing courses connoted with elimination of dust, and (3) t o preserve

the o r i g i n a l ciTown and thickness (58). Dow (52) states that maintenance

i s as important as construction and the most inqportant factor i n maintenance

i s timing. The r i g h t operation must be-done at the r i g h t time. Maintenance

practices may be outlined i n three general phases; blading, retention of

moisture bond with calcium chloride, and patching (55).

Blading should be done immediately a f t e r a r a i n or even commenced

near the end of a r a i n . This i s due to the f a c t that during a dry s p e l l the

calcium chloride tends to concentrate near the surface of the road and blad-

ing at t h i s time i s l i k e l y t o cause loss of the chemical. Also the blade

can cut deeper without tearing when the road i s wet (8, 52). Under average

conditions calcium chloride st a b i l i z e d roads require considerably less blad­

ing than untreated roads (181). Stegner (182) reports that about 75 per

cent less blading i s required. Downey (159) recommends f a i r l y l i g h t blading

from the center of Uie road towards the sides t o eliminate chatter bumps,

pot holes and other minor i r r e g u l a r i t i e s during l i g h t rains. Then a f t e r the

r a i n , while the road surface and accumulated material are s t i l l moist, the

loose material i s bladed back i n t o the road and shaped. Final blading and

f i n i s h i n g i s continued with multiple blade maintainors i r t i i l e the surface i s

compacting under t r a f f i c .

Ifoisture i s maintained i n the stabilized road by l i g h t applications

of calcium chloride, 3/4 l b . per sq. yd. i n spring, and 1 l b . per sq. yd.

25.

i n the summer or whenever the surface begins t o show signs of drying or dusting (61, 1 5 0 ) . I t i s much better t o make frequent l i g h t applications of calcium chloride than heavier treatments less often (118).

Patching i s only necessary during long dry spells, as blading a f t e r

rains i s usually s u f f i c i e n t to preserve smooth r i d i n g q u a l i t i e s . Any scat­

tered p i t s which may develop during dry spells can be eliminated by patching

with a mixture of graded aggregate under ̂ i n . i n size, mixed with an equal

weight of stable sand-clay, water t o the extent of 6 t o 10 per cent, and

calcium chloride at a rate of 100 t o 150 l b . per cu. yd (118). Wagner ( 7 6 )

recommends a patching procedure consisting of sweeping the depressions clean

of loose material with a s t i f f brush, covering the depression with calcium

chloride cmd f i l l i n g with gravel. The surface of the patch i s then covered

with calcium chloride. This method has been found t o be p a r t i c u l a r l y adapt­

able i n the maintenance of calcium chloride stabilized roads i n public parks.

Cost

The costs of surface consolidation and s t a b i l i z a t i o n vary consider­

ably depending on the following factors: (118).

1. Condition of pre-existing road i n surface consolidation.

2. Costs of delivered f i n e and coarse aggz^gate.

3. Cost of the s o i l binder.

4 . Applying water, i f necessary.

5. Ulxlng.

6. Spreading.

7 . CcHnpaction. 8. Calcium Chloride.

The cost of the aggregate i s by f a r the greatest item and i s the primary

26.

cause of the great var i a t i o n i n t o t a l cost. Excellent symposiums have been

prepared on t o t a l costs of various projects i n d i f f e r e n t sections of the

country.

A review (118) of construction costs i n Indiana, I l l i n o i s , Michigan

and Minnesota showed remarkable uniformity when the costs of the aggregate

was considered separately from the other costs of construction and materials.

Charts were prepared of these costs and are presented i n Figures 8 and 9.

CesfptfAli/*, ao/fer3 r n Figure 8. Cost of SUbUlzatloa Proceu per

Mile. (Does not ladade eoit of new agcre-gates.) Items Indnded are (I) Prepared Bloder-SoU. (2) Water AppUed, (3) MlHag. (4) Spreading, (5) Compaction and (6) Caldnm Chloride (M lb. per iqaare yard). Based on cost of Hi per ton for compacted (14S lb. per cn. ft.) stabilised mixture In place plus cost of calcium chloride (at S23 per ton) applied at the rate of 1 i lb. per sq. yd. Twenty-fire cents per ton equivalent to ¥H per cu. yd. (3900 lbs.) 1.4̂ per sq. yd. per In. of depth.

Cosfofnttv

Coafptr /r>ihp*r tneh efefap/h. eto/Zora

Figure 9. Cost of New Aggregates as Af­fecting and in Additton to the Cost of SUbllisa-tion. Baaed on the practlcsl assumption that 80 per cent of the compacted stabilised mixture is aggregate (retained on 100 mesh sieve) and the final oonvacted weight of mixture equals 145 lb. per cu. ft.

Farnsworth (138) reported i n 1939 the construction cost of 3-in.

stabilized surfaces 20 f t . wide as $2321.00 per mile.

Glasgow (138) gave a cost of $2500.00 per mile f o r stabilized suiv

faces 18 f t . wide and 3 i n . deep.

Moreland (138) cite d a cost of $0.47 per sq. yd. f o r 6-in. depth of

stabilised gravel base.

27.

The following reports are i n d i v i d u a l eases not considered i n the

sjnnposiums.

Tiney (20) reported i n 1934 the costs of sxxrface consolidation i n ­

cluding construction and f i r s t application of calcium chloride varied from

$100 t o $400 per mile depending upon the location of clay and other fac­

t o r s .

M i l l e r (38) i n 1935 presented the breakdown of costs f o r a l | - i n .

compacted stabilized mat using calcium chloride on 1400 sq. yd. of surface

as: 60 cu. yd. gravel - $f54.00 Screening and delivering gravel - $12.00 (^-mile haul) Clay, 20 cu. yd. - $1.00 Delivery of clay - $9.00 Mixing, spreading, and compacting - $18.00 Calcium chloride, 2520 l b . - $36.00

Total - $130.00

The t o t a l cost of a new base, 3 i n . deep, 20 f t . wide constructed

i n 1935 i n Michigan was $1650 per mile (39).

Bateman (108) reported i n 1938 the costs of surface consolidation

using additional binder s o i l and calcium chloride and gravel mixed at the

p i t as being $80 to $100 per mile.

The Effect of Calcium Chloride on Frost Heaving

The use of calcium chloride i n granular s t a b i l i z a t i o n cannot be en­

t i r e l y divorced from i t s uses as a dust paTH ative and i n some cureas, from

i t s effect on f r o s t heaving and f r o s t b o i l s since these are d i r e c t l y involv­

ed i n the use of the chemical as a s t a b i l i z e r . Thus, i t i s iiq>ossible to

construct a calcium chloride stabilized road having a f i r m w e l l - k n i t wearing

course without that surface being less dusty than i t would be vmder ordinary

conditions. This fact i s brought out f o r c i b l y when we remember that the

f i r s t effects of calcium chloride on s t a b i l i z a t i o n or i n securing a more

28.

dense road course were observed during a study of the chemical as a dust p a l ­l i a t i v e ( 6 ) .

The same i s true of f r o s t heaving. The most detailed,work on the mi­

gration of calcium chloride solutions through s o i l was not undertaken with

the purpose of i t s e f f e c t on s t a b i l i z a t i o n but rather on f r o s t heaving (185)•

The lower freezing point of calcium chloride solutions i s well known and has

many uses i n other f i e l d s . Davis (171) has prepared a series of calcium chlo­

ri d e nomographs which give the properties of calcium chloride solutions such

as specific gravity, concentration, and freezing points. Lang (83) suggests

the lowering of the freezing point of the s o i l moisture by the use of c a l ­

cium chloride as being benefic i a l i n the reduction of f r o s t heaving. Winn

(117) states that Calcium chloride d e f i n i t e l y reduces f r o s t action because

of the lowering of the freezing point and that 2 or 3 per cent of calcium

chloride w i l l reduce f r o s t action t o a minimum by preventing freezing at

minus 10 t o minus 15 deg. F. On a construction Job i n Maryland the problem

of cold weather concreting and the protection of the subgrade from freezing

between the time the grade was prepared and the placing of the concrete was

c r i t i c a l (166). I n t h i s s i t u a t i o n the frozen earth was excavated, stock­

p i l e d , and thawed by applying 2 l b . of calcium chloride over each 2 f t .

layer i n the stoclqjlle. The stockpiled material was thus kept i n excellent

condition except f o r a s l i g h t crust even though sub-freezing tenqseratures

prevailed. An application of i j l b . of calcium chloride per sq. yd. was

made on the grade and worked i n t o a depth of 2 i n . and then covered with

9 i n . of marsh grass hay. This protected the grade from freezing before

paving.

A special Committee of the Highway Research Board i s now studying

the problem of subgrade treatment f o r f r o s t prevention and an outline f o r

29. the investigational work has been prepared and arrangements made with several State highway departments f o r experimental i n s t a l l a t i o n *

These are j u s t a few of the references to the use and effect of c a l ­

cium chloride i n reducing detrimental f r o s t action. The bibliography i n ­

cludes others f o r completeness of the subject.

Summary

A c r i t i c a l review and analysis of the available l i t e r a t u r e dealing

n i t h the use of calcium chloride i n granular s t a b i l i z a t i o n has been made and

a con^irehensive bibliography has been prepared with comments on the subject

of each reference. Classified and author indexes to t h i s bibliography have

also been made t o f a c i l i t a t e i t s use.

This study has brought out a number of facts concerning the use of

calcium chloride that are substantiated by laboratory or f i e l d investiga­

t i o n s . These are:

1. Calciim chloride migrates through s o i l i n the form of a solution. Dur­

in g dry spells i t tends t o concentrate near the surface and during wet

spells i t i s carried downward by leaching.

2. The rate of evaporation of moisture from s o i l i s reduced by calcium

chloride, thus maintaining the moisture that i s necessary f o r the de­

velopment of cohesion i n s o i l s , an essential of s t a b i l i t y . •

3. Conqpaction i s f a c i l i t a t e d so that the desired density i s obtained with

less coiqjactive e f f o r t .

k» Aggregate loss i s reduced. A reduction from 100 per cent f o r an un-

traated road t o 37 per cent f o r a treated road i s given f o r a controlled

project.

5. Treated s t a b i l i s e d roads are less inclined t o dusting than untreated

roads.

30.

6, Laboratory studies show that the detrimental effects of freezing are ma­t e r i a l l y reduced by the use of calcium chloride.

7. Uaintenance blading and upkeep costs are less on calcium chloride treated

stabilized roads.

On the basis of the foregoing facts i t i s concluded that the use of

calciiam chloride i s J u s t i f i e d from the viewpoint of obtaining a more stable

wearing or base course which w i l l give better t r a f f i c service with less main­

tenance. This includes the following road types:

1. S t a b i l i z a t i o n , vrtiich involves the adjustment of soil-aggregate composi­

t i o n so that i t w i l l consist of a dense wearing course or base composed

of a designed mixture of graded aggregate, binder s o i l , and calcium

chloride.

2. Surface consolidation, nhich involves adding binder s o i l to f i l l the

voids and to furnish the cohesive constituent suid calcium chloride t o

maintain the proper moisture content t o gravel or stone already i n place.

3. Bust laying, which involves the application of calcium chloride t o ag­

gregate or clay surfaces t o supply moisture.

Further Research

The data reviewed show that there i s a d e f i n i t e relationship between

the use of calcium chloride and compaction since the densities of calcium

chloride treated soils and soil-aggregate mixtures are greater than those of

the untreated materials. The exact reason f o r t h i s relationship i s not

clearly established. There i s some indication t h a t , because of the increased

surface tension of calcium chloride solutions over that of water and the pos­

s i b i l i t y that calcium chloride solutions provide thinner moisture f i l m s ,

greater density i s obtained. However, t h i s point i s not d e f i n i t e l y proven.

A study designed to determine the exact nature of the effect of calciiun chlo-

31.

ride on density should be of value f o r i t might w e l l lead to better u t i l i z a ­

t i o n of the material through changes i n practice.

There has been a decided tendency toward the reduction of the plas­

t i c i t y index of the s o i l binder used i n s t a b i l i z a t i o n . There have been num­

erous instances i n which the nature of the s o i l binder has changed r a d i c a l l y

from one l o c a l i t y t o another and even from one road section to another. This

difference i s undoubtedly due to a change i n the clay f r a c t i o n of the binder.

Hogentogler and W i l l i s (70) and Rapp and Mizroch (149) have indicated the im­

portance of t h i s f r a c t i o n i n determining the behavior of s o i l s p a r t i c u l a r l y

through base-exchange. Since, i n granular s t a b i l i z a t i o n , we are dealing with

clays irtilch are p a r t i a l l y saturated with calcium chloride we can e^qject such

reactions t o take place, and because of the fact that clay w i l l d i f f e r from

one location t o another i t i s reasonable t o expect that the results w i l l d i f ­

f e r with d i f f e r e n t clays or clay-minerals. A study of these differences

might cast further l i g h t upon the exact nature of the behavior and effe c t of

calcium chloride i n granular s t a b i l i z a t i o n and particularly- upon i t s benefic­

i a l effect on density.

As one reviews the l i t e r a t u r e that has been wri t t e n on the use of

calcium chloride i n s t a b i l i z a t i o n he cannot help but be impressed by the

large number of reports describing i t s use i n various l o c a l i t i e s . Most of

these reports have been w r i t t e n either during the construction of the road,

or immediately a f t e r , and consequently include only b r i e f mention of the

behavior of the road usually covering only one year or one season. While

these reports are of great value i n establishing references which can be

cited when precedents are required they would be of much greater value i f

they covered a longer period of time. A suirvey of the behavior of these

32.

roads over a period of years covering such items as performance, maintenance, and cost would add much to the general knowledge of t h i s type of construc­t i o n .

The w r i t e r i s Indebted t o the Library Staff of the Public Roads Ad­

min i s t r a t i o n , Washington, D. C. f o r assistance i n assembling most of the

reference material from which t i l l s study was made.

APPENDIX

ANNOTATED BIBIIOGSAPHZ

ON USE OF

CALCIUU CHLCHilDE IN

GRANULAR STABILIZATION

OF ROADS

mOIHAI RESEARCH BOARD 1945

33,

34. CLASoiFIED SUBJECT INDEX

The numbers l i s t e d are those of the references i n the bibliography.

Principals of S t a b i l i z a t i o n ; Fundamental a r t i c l e s on granular s t a b i l i z a ­t i o n and the use of calcium chloride. I , 6, 8, 9, 13, 15, 18, 21, 24. 35, 36, 37,'40, 58, 70, 79, 81, 85, 86, 101, 118, 139, 140, l U . 194.

Frost Prevention; Ar t i c l e s dealing with theory of f r o s t prevention and the use of calcium chloride. — ^ — n

'Construction Procedure; 14, 40, 43, 53, 54, 57, 63, 71, 92, 105, 107, 116, 142, 146, 150, 157, 159, 162, 165, 174, 179, 180, 190, 191, 192, 194.

Cost; 20, 38, 44, 89, 91, 94, 108, 118, 138, 182, 191. P i t or Plant Mixing; 26, 50, 60, 66, 68, 75, 80, 104, 112, 113, 127, 152,

153, 168. General; A r t i c l e s containing information of general int e r e s t t o those con­

cerned with problems of granular s t a b i l i z a t i o n . 7, 21, 30, U, 45, 56, 58, 70, 79, 85, 87, 95, 97, 101, 103, 106, 118, 121, 123, 125, 128, 132, 139, 145, 155, 156, 186, 187.

Properties of Calcium Chloride; Physical and chemical properties of c a l ­cium chloride important i n s t a b i l i z a t i o n . 15, 22, 33, 35,-37, 70, 81, 86, 100, 111, 122, 133, 171, 193.

Stage constmiction; Description of road projects i n which stage construc­t i o n was the goal. 10, 51, 61, 67, 87, 90, 105, 106, 112, 131, 144, 168, 183, 191.

Road Pro.lect Reports; Reports giving information of actual construction Jobs i n which calcium chloride has been used. Mostly of a general nature. I I , 12, 16, 17, 19, 23, 27, 29, 32, 34, 39, 42, 47, 48, 49, 54, 59, 61, 62, 64, 74, 77, 78, 89, 92, 93, 96, 98, 102, 105, 115, 120, 135, 142, 154. 158, 162, 167, 174.

Maintenance; 13, 24, 44, 52, 55, 72, 76, 114, 116, 150, 159. Surface consolidation; 28, 39, 42, 49, 65, 91, 108, 110, 116, 124, 131,

134, 135, 159, 160, 164, 180. Streets; A r t i c l e s describing the use of calcium chloride i n the construc­

t i o n of streets. 46, 69, 73, 88, 99, 109, 129.

Technical; Reports describing laboratory and f i e l d e:qperlments designed , to t e s t and Improve the use of calcium chloride i n granular s t a b i l i z a ­t i o n . 81, 82, 122, 126, 130, 136, 137, 147, 149, 151, l 6 l , 178, 184, 185, 188.

35. AUTHOR INDEX

The numbers' l i s t e d are those of the references i n the bibliography.

Aaron, H., 31 Abercrombie, W. F., 138 Allen, L. L., 102 Ames, J. H., 109 Amstutz, U. E., 168-—— — Atkln, B., 65

Baise, W. V., 92 Barr, J. H., 28, 34, 39, 45 Bateman, L. L., 108 Belcher, D. J., I 6 l Belknap, L., 28 Benkelman, A. C., 3t 4 Beskow, G., 119 Best, 7. E., 99 Black, J. C, 113 Blessing, 0* D., 24 Blongren, £. E., 12 Blcmqulst, G. C., 178 Bri c k l e r , A. R., 90 Briggs, C. F., 118 Brown, A. L., 138 Brown, F. L., 138 Broim, V. J., 140 Burggraf, F., 6, 40, 57, 103, 118,

130, 137, 151 Buznlster, D. U., 122 Burrldge, A. L., 115 Burton, 7. R., 3

Carpenter, C. A., 136 Casagrande, A., 5 Casagrande, L., 163 Caslin, P., 167 Chambers, U., if6 Clemmer, H. F., 79, 97, 138 Collings. W. R., 13, 21 Cornier, G. J., 120

Davis, D. S., 171 Dick, U., 51 Dow, W. 0., 16, 44, 52 Downey, B. R., 114, 118, 159, 179

Elleman, J. H., 118, 139. 150 Eno, F. H«, 19 Evans, W. £., 95

Farnsworth, G., 138 Flanders, J. 0., 42 French, R. D., 30

Geslin, H., 177 Glasgow, P. 134, 138, 142 GLover, 7. L., 36 Goetz, K., 167 G r i f f i n , I . ' B., 162

Halbfass, F. P. G., 135 Hathaway, C. U., 35, 156 Hemmerick, G., 155 Herzog, J. E«i 174 Hess, Otto, 115 Hicks, W. B., U Hogentogler, C. A., 33, 37, 70, 85,

86, 101, 118, 121, 145 Hogentogler, C. A. J r . , 9, 10, 81 Housel, W. S., 63 Huber, J., 51 Hurst, E. G., 67

Kelley, J. A., 101 Kellogg, F. H., 191 Knight, J. A.. 53, 91, 118 Kushing, J. W., 12

Lang, F. C, 59, 83, 87 Lieberman, E., 123 L i n z e l l , S. 0., 47, 78

Maddison, L., 188 Ucdain, C. W., 17, 84 M i l l e r , H. H., 25, 128. 165, 167,

180 M i l l e r . R. W., 38. 82 M i l l s , E. L., 131 Mizroch, J., 149 Uoreland, J. E«, 138 Munis, I . B., 2

Nunn. E. H., 157, 166

Olnstead, F. R., 4, 152. 153, 187 Osterberg, J. 0.. 143

36.

Patterson, T. R., 49 Pehrson, H. V., 164 Petty, B, H., 190 Proctor, R. R., 15

Ranney, A. P., 98 Rapp, P., 149 Ravn, H. H., 148 Reppel, J. W., 54 Root, W. H., 146

Schaible, L., 176 Schaub, J. G., 144 Schmid, A., 175 Schmitt, J. S., 158, 181 Sellars, A., 93 Shaw, J., 184 Slate, F. O . , 172 Slater, F. A., 68 Slesser, C, 185 Smith, A. J r . , 154 Smith, D. N., 24, 25 Smith, P. C, 147 Sours, H. G., 41, 43, 45 Stegner, A* F., 182

Stewart, L. C, 13, 21, 50, 104 Strahan, C. U., 1 Swinton, R. S., 126

Thomas, B. P«, 173 Tiney, B. C, 20 , 71, 106, l l 6 Travers, R. B., 14, 61, 125 Tremayne, J. £•• 124 Tribble, J. F., 193 Tyler, P. M., 22

Van Auken, W. T., 160

Wagner, H. S., 76 Warren, S. S., 8, IB Webster, F. W., 191 White, S. J., 50 Whitton, R. M., 138 Vttlford, H. D., 62, 89, 118 tail i a m s , A. U., 115 v a i l i s , E. A., 70, 136, 147 Winn, H. F., 117 Wood, J. £., 192 Wooley, W. R., 141

37. BIBUOGSAPHI

1. "A Study of Gravel, Tops o i l and Sand-Clay Roads i n Georgia.** C. M. Strahan. Public Roads, Vol. 10, No. 7, 1929.

Can be considered fundamental work on s t a b i l i z a t i o n establishing f o r f i r s t time' the relationship between gradation and q u a l i t y of

^ sand-clay roads,

2. / '*Illu8trations of Frost and Ice Phenomena.** I . B. U u l l i s . Public ^ Roads, Vol. 11, No. 4, 1930. >K

Physical characteristics of lee formation i n s o i l s and how i t i s ^ manifested i n highways and s o i l s .

3. "The Relation of Certedn Frost Phenomena t o the Subgrade.** V. R. Burton and A. C. Benkelman. Proc. Highway Research Board, Vol. 10, ^ 1930.

Data on subject of t i t l e supported by laboratory evidence. /

4. "A New Theory of Frost Heaving." A. C. Benkelman and F. B. Olnstead. Proc. Hl^way Research Board, Vol. 11, 1931.

Results indicate excessive heaving may occur i n s o i l s of any grading or texture providing s u f f i c i e n t water i s present.

57 •'Discussion on Frost Heaving.** A. Casagrande. Proc. Highway Research Board, Vol. 12, 1932. Y

Differences i n various theories of f r o s t heaving are presented and conclusions of e:q>erlments.

6. **The Use of Calcium Chloride as a Dust Palliative.** Fred Burggraf. Proc. Highway Research Board, Vol. 12, 1932.

Recognition that use of calcium chloride as a dust pcQllatlve has d e f i n i t e e f f e c t on s t a b i l i t y of road.

7. "Soil S t a b i l i z a t i o n i n Highway Construction through Calcium Chloride." - Public Works, Vol. 64, No. 6, 1933.

General report of a l l types of s t a b i l i z a t i o n being done i n va^ rious sections of the country.

8. "Stabilization of T r a f f i c Bound Roads through the Calcium Chloride Method." S. S. Warren. Better Highways, Vol. 16, No. 6, 1933.

Points out advantage of getting same bearing or incorporation of s u f f i c i e n t metal i n road bed i n one year or one spread as could take three t o f i v e years under ordinary gravel road main­tenance procedure.

9. "Stabilization of Low-Cost Roads by Calcium Chloride." C. A. Hogen­tog l e r , J r . , Roads and Streets, Vol. 76, No. 10, 1933.

Considers physical aspects of what makes a stable s o i l mixture and irtiy.

10. *'Moistur»-Fllffl, Cured Macadams." C. A. Hogentogler, J r . , Public Works, Vol. 64, No. 11, 1933.

Stabilized bases with calcium dslorlde, properly seasoned, af­ford good bases f o r macadam covering.

38.

11, "Stabilizing Earth Roads." Engineering Hews Record, Vol, 111, No. 19, 1933.

Short note of general type of work being carried on i n Ulchigan and i n Onondaga county. New York.

12, "Stabilizing Ulchigan Gravel Roads with Clay and Calcium Chloride." E. E. Blomgren and J * W. Kushing. Public Works, Vol. 64, No. 12, 1933.

liethod of construction described. 13, "Preparation and Uaintenance of Stabilized Gravel Roads." W. R.

Collings and L. C, Stewart. Am. Road Builders' Assoc., B u l l . No. 36, 1933.

General review o f a l l phases of calcium chloride granular s t a b i l ­i z a t i o n .

14, "Qravel Type Stabilized Surfaces f o r Secondary Roads." R. B. Traver and W. B. Hicks. Proc. Highway Research Board, Vol. 13, 1933.

Uethods and materials of construction described i n some d e t a i l .

15, "Fundamental Principles of S o i l Compaction." R. R. Proctor. Sigineer^ ing News Record, Vol. I l l , Nos. 9, 10, 11, 12, 13, 1933.

Theory and practice of s o i l coiqpaetlon. 16, "St a b i l i z a t i o n of Gravel Roads by Use of Calcium Chloride." W. 0, Dow.

Tirentieth Ann. Road School, Purdue University, 1934. General use i s described and b r i e f accounts of various road INmJects presented.

17, "Stabilization of Gravel Roads by Use of Calcium Chloride." C. W. UcClaln. Twentieth Ann. Road School, Purdue University, 1934.

Bri e f account of project I n Indiana.

18, "Principles of Road S t a b i l i z a t i o n . " S. S. Warren. Highway Topics, Vol, n . No, 8, 1934.

General review of practice of s o i l s t a b i l i z a t i o n . 19, "New Application of Old Principle." F. H. Qm. Ohio SUte University

Sn^^eerlng ^cpeAwant Station News, Vol. 6, No, 1 , Part I , 1934. Refers to Strahan*s work i n Georgia. Note that calcium chloidde .stabilized road i s being tested i n Ohio.

20, "Soil S t a b i l i z a t i o n Insures Good low-Cost Roads. B. C. Tiney. Highway Uagazine, Vol. 25, 1934.

U t i l i z a t i o n of f i n e material i n gravel, construction, «md mainte­nance of gravel roads cost $100 to |400 per mile.

21, "Stabilized Soil-Bound Surfaces." W. R. Collings and L. C. Stewart. Engineering News Record, Uay 24, June 7, 14, and 21, 1934.

Cosplete series of a r t i c l e s on a l l phases o f use of cal&ium chloride i n granular s t a b i l i z a t i o n .

39.

22. "Calcium Chloride." P. M. Tyler. U. S. Bureau of Mines, Infonnation Circular 678I , 1934.

Nature, manufacture, occurrence, and properties of calciiun chloride.

23. "Ohio Engineers 7iew Stabilized Roads-in Oakland County." Michigan Roads and Airports, 7ol. 3 1 , No. 21 , 1934.

Announcement of v i s i t s of engineers t o project.

24. "Stabilization and i t s Relation to Maintenance of Traffic-Bound Roads." Olin D. Blessing and Don N. Smith. Better Roads, 7ol. 4 , No. 6, 1934.

Explains purpose of s t a b i l i z a t i o n and i t s usual applications.

"Methods f o r Prevention of Road Failure Due to Frost." H. H. M i l l e r and Don N. Smith. Roads and Streets, 7ol. 77, No. 6, 1934. X

Two treatments irtiich have successfully eliminated f r o s t ftdlures i n roads.

26* "Producer Makes Special Mixture f o r Cedcium Chloride treated Road Sur­faces." Rock Products, 7ol. 37, No. 6, 1934.

T i t l e ejqplanatory.

27. "State Tests New Type Road Surface." Minnesota Highway NeWs, July 25. 1934.

Note th a t calcium chloride st a b i l i z e d roads are being construct­ed and tested i n Minnesota.

28. "Stabilization of Resurfacing Cbravel." Leon Belknap and John Barr. Public Works, 7ol. 65, No. 8, 1934.

Methods of construction described f o r t h i s type of work i n Oak­land county, Michigan.

29. "Indiana Stabilizes Many Miles of Gravel-Surfaced State Highways." Outdoor Indiana, 7ol, 1 , No. 7, 1934.

More than 250 miles of gravel surfaced roads being treated.

30* "Soil Concretes, Performances and P o s s i b i l i t i e s . " Prof. R. Del French. Canadian Qigineer, 7 o l . 67, No. 12, 1934.

General ireview of principles of s t a b i l i z a t i o n .

3 1 . "Frost Heave i n Highways and i t s Prevention." Henry Aaron. Public K Roads, 7ol. 15. No. 1 , 1934.

T i t l e explanatory.

32. "Stabilized Roads i n West Vir g i n i a . " Wast 7 i r g i n i a Highways, January, 1935.

Report of use of stabilized gravel roads.

33. "Soil S t a b i l i z a t i o n . " C. A. Hogentogler. Proc. of the Eleventh Ann. Convention, Assoc. of Highway O f f i c i a l s of the North A t l a n t i c States, 1935.

General discussion on subject u t i l i z i n g physical-chemical re­lationships of s o i l s .

40.

34. "Stabilized Surfaces i n Oakland County." John H. Barr. Twenty-first Ann. Highway Conference, University of Michigan, 1935*

Description of eQq>erlences I n Oakland county, Michigan using both plant and ro&i mix methods of preparing calcium chloride stabilized materials.

35. "Stabilized C&ravel Roads, Theory and Practice." C. M. Hathaway. Twenty-second Ann. Conference on Highway Engineering, University of I l l i n o i s , 1935.

T i t l e explanatory. 36. "Practiced S o i l S t a b i l i z a t i o n . " 7. L. Glover. Twenty-second Ann. Con­

ference on Highway Engineering, University of I l l i n o i s , 1935. Genex>al review of f i e l d of s t a b i l i z a t i o n .

37. ' "Practical S o i l S t a b i l i z a t i o n . " C. A. Hogentogler. Twenty-second Ann. Conference on Highway Engineering, University of I l l i n o i s , 1935.

Discussion of the physical properties of soils cmcerned with s t a b i l i z a t i o n .

38. "Cost of Building Stabilized Roads." R. W. M i l l e r . American City, 7ol. 50, No. 2, 1935.

Detailed costs of two projects i n Minnesota presented. Costs vary with thickness of mat, cost of materials, etc.

39* "Stabilized Surfaces i n Oakland County." John H. Barr. Michigan Roads and Construction, Vol. 32, No. 11, 1935.

Con9>lete descriptions of methods of construction, costs, and findings on one project.

40. "Progress i n Road S t a b i l i z a t i o n by Use of Calcium Chloride." F.' Burggraf. Roads and Streets, 7ol . 78, No. 4, 1935.

Developments i n road s t a b i l i z a t i o n such as; specifications, de­sign, eonstiructlon, and maintenance.

41* "Progress i n Stabilized Traffic-Bound Roads." H. G. So\irs. Better Roads, Vol. 5, No. 4, 1935.

General review of s t a b i l i z a t i o n . Two methods of application of calcium chloride described; surface application and I n t e g r a l n i x .

42. "Resurfacing Gravel or Stone Roads i n Townships." J. D. Flanders. Canadian Engineer, Vol. 68, No. 19* 1935.

Methods of s t a b i l i z a t i o n used i n DeMbam township.

43* "Stabilized Roads a Real Job." H. G. Sours. Contractors and ItigX-neers Monthly, Vol. 30, No. 5t 1935.

Results and conclusions of experiences with s t a b i l i z a t i o n i n Ohio. Methods of construction described.

44. "Notes on the Maintenance of Stabilized (k«vel Roads." W. 0. Dow. Better Roads. Vol. 5. No. 5, 1935.

Tims of repair i s c r i t i c a l . Methods described. Breakdown of costs.

41.

45. "Low-Cost Road Building, A Syniposlum.'* Contributors, J . H. Barr and H. G. Sours. Engineering News Record, Vol. 114, No. 26, 1935.

Accounts of experience and practice condensed from recent papers presented at meetings of road builders covering federal stand­ards, farm service, o i l mix, stabilized s o i l , and tar^retread.

46. "Ijqproving City Streets Through Low^Cost Stabilization." Mark Chambera American City, Vol. 50, No. 7, 1935.

Soil tests of existing surfaces revealed lack of binder material and some gravel i n earth surfaces. Treatments described.

47. '*Stablllzed Roads, Practical, Simple and Economical." S. 0. Lin z e l l . Highway Magazine, Vol. 26, p. 209. 1935.

General description of work i n l&>rrow county, Ohio.

48. "Stabilization of Ontario Roads with Calcium Chloride." Canadian B»-glneer. Vol, 69, No. 11, 1935.

Impetus in Interest caused by manufacture of calcium chloirlde at Amherstburg, Ontario. General description of construction work being carried out.

49* "Huron County's (Michigan) Experience i n Stabilizing Gravel Roads." T. R. Patterson, Canadian Engineer, Vol. 69, No. 13» 1935.

Title ejqilanatory.

50* "Premixed Stabilized Soil for Road Surfaces," L. C. Stewart and S. J . White. Engineering News Record, Vol. 115. Bo. 12, 1935.

Details, including design of demonstration plant built for pro­ducing stabilized gravel.

51* "Stabilized Gravel as Base Course for Bituminous Surfacing," J . Huber and M. Dick. Public Works, Vol. 66, No. 9, 1935.

Description of work in Washtenaw county, Michigan i n which staF-billzed gravel road was constructed, malntidned for one year, and then a thin bituminous coating applied. Very satisfactory results.

52. "Maintenance of Stabilized Gravel Roads," W. 0. Dow. Michigan Roads and Construction, Vol. 32, No. Z»2, 1935.

Maintenance i s as important as construction. Most important factor i s time. Practice described.

53. "Stage Stabilization of Gravel Roads." J . A. Knight. Canadian Engi­neer, Vol. 69, No. 27, 1935.

Maintenance of gravel roads should be considered as progressive step toward the goal of a stabilized gravel road. Stages nec­essary for this development are described,

54. "Experimental Stabilization i n Ohio," J , W. Reppel, Roads and Streets, Vol. 78, No. 12, 193$.

Title explanatory.

42.

55* '*UalnteRance of Caldiim Chloride Stabilized Roads." Calcium Chloride Assoc. Bull. No. 18, 1935.

Title eaq>lanator7.

5 6 . "Outline for low-Cost Road Inqarovement Through Stabilization with Binder Soil and Calcium Chloride." Calcium Chloride Assoc. Bull. No. 22, 1935.

Title explanatory. 5 7 . "Iiqwrtance of Cronn on Calcium Chloride Stabilized Roads." F. Burggraf.

Calcium Chloride Assoc. Bull. No. 231 1935. Recammendations for type of crown based on observations and meas­urements of many roads i n service.

58. "Calcium Chloride Stabilization." Report of Special Committee, Highway Research Board, 1935*

Conqplete report on calcium chloride stabilization. 5 9 . "Stabilization of Soil and Gravel Roads." F. C. Lang. Convention Proc.

Am. Road Builders Assoc., 1935-1936. Review of methods used in construction of stabilized roads i n Ulnnesota. Progress of stabilization i s retarded by lack of proper eqjiipment and insufficient knowledge as to proper construc­tion and maintenance methods.

6 0 . "Pioneer (k'aval Squipment"- lUchigan Roads and Construction, 7ol. 33* No. 2, 1 9 3 6 .

Description of a portable gravel clay stabilizer plant designed to work i n conjunction with a crushed gravel plant and to pre­pare and mix materials for stabilization.

61* "LoiF-Cost Stabilized Road Construction." R. B. Traver. Canadian Ekigi-neer, 7ol. 7 0 , No. 8, 1936.

Itethods of procedure and construction of stabilization i n Onondaga county, New York described i n detail.

62. "Stabilizing Gravel Roads i n l^ctorla County." H. D. Wilford. Canadian Engineer, Vol. 70, No. 8, 1936.

Report of construction.

63. "Subgrade Stabilization." W. S. Housel. TWenty-second Ann. Highway Conference, University of Ulchlgan, 1936.

In low cost surfaces such as stabilized roads i t i s difficult to demarcate between roadway structure and i t s foundation. Discus­sion on principles and methods.

6k. "Stabilized Soil Road Withstands Erosion." Roads and Streets, Vol. 79t No. 2, 1 9 3 6 .

Illustration showing calcium chloride stabilized road after tor^ rential rain, near Vlncennes, Indiana.

43. 65, "Gravel and Broken Stone Surfaces." Bernard Atkin. T»fent7-third Ann.

Conference on Highway Engineering, University of I l l i n o i s , 1936. 7alue of calcium chloidde use i n s t a b i l i z a t i o n recognized on a l l road sections b u i l t during past tvio years.

66, "Detroit Plant Uses Crushed Slag to Make Stabilized Road Mixture." P i t and Quarry, Vol. 28, No. 8, 1936.

T i t l e explanatory.

67, "Smoothing Stabilized Gravel f o r Asphalt Surfacing." E. G. Hurst. Engineering News Record, Vol. 116, No. 15, 1936.

Unique problem of one pa r t i c u l a r road and i t s preparation f o r asphalt surface.

68, "Plant Production of Stabilized Mix.". F. A, Slater. Canadian Ekigi-neer. Vol. 70, No. 15, 1936.

Production of stabilized gravel containing specified propor­tions calcium chloride, clay, sand, and pea gravel described.

69, "Stabilization f o r Street Improvement," Public Works, Vol, 67, No. 4. 1936.

B r i e f descriptions of street s t a b i l i z a t i o n Jobs i n Lansing, Michigan; Ames, Iowa; and De t r o i t , Michigan, Both road and plant mix methods used.

70, "Stabilized S o i l Roads." C, A, Hogentogler and E, A, W i l l i s . Public Roads, Vol. 17, No. 3, 1936,

Discussion of the physical and chemical properties of s o i l i n ­volved i n s t a b i l i z a t i o n ; e f f e c t of deliquescent chemicals des­cribed.

71, "Shoulder S t a b i l i z a t i o n . " B, C. Tiney. Roads and Streets, Vol. 79t No. 7, 1936.

Methods of construction of calcium chloride stabilized road shoulders. Central mixing plant suggested.

72, "Solving Gravel-Road Maintenance Problems." Better Roads, Vol, 6, No, 8, 1936.

Reports of very satisfactory results by using csdcium chloride and clay i n maintenance.

73, "Detroit Builds S o i l Pavements," Calcium Chloride Assoc, News, August, 1936, p. 5.

B r i e f note of what i s being done, 74, "State Highway Department Builds Test Stabilized Road." Pennsylvania

Road Builder, Vol, 9, No, 9, 1936. Limestone screenings, clay, and calcium chloride added t o gravel road according t o tests showing deficiencies.

75, "Michigan Gravel Firm Takes Advantage of Demand for Stabilized Road Material," P i t and Quarry, Vol, 29, No, 4, 1936.

Description of production of stabilized s o i l aggregate mixture.

76.

77.

7 8 .

79.

81.

82.

"Patching Calcivun Chloride Roads." H, S. Wagner. Parks and Recrea­t i o n . Vol. 2 0 , No. 2 , 1 9 3 6 .

Suggest expensive blading, planing, and reshaping can be elim­inated or confined to once or twice a year by proper patching. Uethod described.

"Stabilized Road Construction i n Minnesota." Earth Mover, 7ol. 23, No. 10, 1 9 3 6 .

Use of three methods; road nixed by blading, machine mixed on road, and plant mixed f o r preparing stabilized material. Cal­cium chloride used i n a l l .

"Stabilized Road Surfacing i n Ohio." S. 0. L i n z e l l . Roads and Streets, Vol. 79, No. 11, 1936.

Calcium chloride used .in surface application only.

"Stabilization of Soils." H. F. Clemmer. Roads and Streets, Vol. 7 9 , No. 1 2 , 1 9 3 6 .

General review of principles of s o i l s t a b i l i z a t i o n .

"Plant Mixing Stabilized Aggregates f o r Low-Cost Roads." Calcium Chloride Assoc. B u l l . No. 24, 1936.

Design of plant and details of mix f o r preparing plant mixed stabilized aggregate.

Essentials of S o i l Coiqjactlon." C. A. Hogentogler, J r . Proc. High­way Research Board, Vol, I 6 , 1936.

Repoirt largely concerned with principles of compaction, con­ditions of moisture, f i l m thickness, and the eff e c t of electro­lytes I n stabilized s o i l s .

"Effect of Quality of Clay on S o i l Mortars." R. W. l & l l e r . Proc. Highway Research Board, Vol. 16, 1936.

Compaction and swell tests indicate that P l a s t i c i t y Index l i m ­i t s of 4 to 12 f o r s o i l fines or minus 40 mesh material cover range usually eneo\interad i n various l o c a l i t i e s .

"Combating Frost arid Drainage Problems." F. C. Lang. Twenty-third Ann. Road School, Purdue University, 1937.

Report on mechanics of f r o s t heaving and methods of combating problem.

"Combating Frost and Drainage Problems." C. W. McClain. t h i r d Ann. Road School, Purdue University, 1937.

Genertd discussion of problem.

Twenty-

"Soll S t a b i l i z a t i o n . " C. A. Hogentogler. Proc. of the Thirteenth Ann. Convention, Assoc. of Highway O f f i c i a l s of the North A t l a n t i c States, 1 9 3 7 .

Review of principles of s o i l s t a b i l i z a t i o n .

4 5 .

86. "The Physical Chemistry of Highway Subsoils." C. A. Hogentogler. Twenty-third Ann. Highway Conference, University of Michigan, 1937.

General study of physical-chemical properties of s o i l and t h e i r influence i n s o i l s t a b i l i z a t i o n .

87. "Methods of S o i l St a b i l i z a t i o n and Low-Cost Roads." F. C. Lang. Twenty-third Ann. Highway Conference, University of Michigan, 1937.

Stresses importance of good subgrade f o r a l l types of road. Methods described.

88. "Stabilized Streets f o r a Housing Project." American City, Vol. 52, No. 2, 1937.

Short ai±icle b r i e f l y describing use of calcium chloride s t a b i l ­ized mixture i n street construction of low cost housing project.

89* "Low^Cost County Road Construction." H. 0 . Wilford. Canadian Engi­neer, Vol. 72, No. 9, 1937.

Review of construction completed and b r i e f statement of future planned work i n Victoria county, Ontario.

90. "Developments i n Road St a b i l i z a t i o n . " A. R. Bidckler. Extension Se­r i e s No. 38t Engineering Extension Department, Purdue University, 1937.

Concerned with s t a b i l i z e d bases. Details on use of several methods of s t a b i l i z a t i o n employing various mixes.

91. "Surface Consolidation Method Produces the 'Costless* Road." J. A. Knight. Highway Topics, Vol. U, No. 11, 1937.

I n past, stages of construction were; d i r t surfaces, gravel, black top, f i n a l l y hard siarfacej now, gravel surface i t s e l f can be b u i l t i n stages by method called "Surface consolidation." , Constiruction details given.

92. "North Carolina Stabilized Job Stands Winter Well." V. Vance Baise. Contractors and Qigineers Monthly, Vol. 3U, No. 5> 1937.

Methods given that were used to construct 5.6 miles of calcium chloride stabilized road. Reported to be i n good condition a f t e r winter.

93. "Stabilizing. Roads with Calcium Chloride." Ainslie Sellars. Canad­ian Engineer, Vol. 73, No. 3, 1937.

B r i e f account of experience i n construction of 1 .25 miles of construction i n North Maiden, Ontario.

94. "Estimating Construction Costs f o r Road St a b i l i z a t i o n . " Public Works, .Vol. 68, No. 7, 1937.

Charts presented showing costs of s t a b i l i z a t i o n and new aggre­gate.

95. "Soil Stabilized Road Construction." W. E. Evans. Roads and Road Con­st r u c t i o n , Vol. 15, No. 176, 1937. (England).

General review of practice i n United States.

4 6 ,

9 6 . "Outstanding Stabilized Road B u i l t Under Contract." Highway Builder, Vol. 16, No. 5, 1937.

Previously most s t a b i l i z a t i o n had been done by highway d e p a i ^ ment. Contract work successful.

97. "Developments i n Municipal Road Surfaces." H, F, Clemmer. Canadian Engineer, Vol. 73, No, 14, 1937.

Maximum density u t i l i z i n g existing sources of supply of ma­t e r i a l s i s prime requisite of stabilized s o i l mix design. Re­view of practice i n United States.

98, "Stabilized Secondary Roads i n Summit County, Ohio," Arthur F. Ranney. Better Roads, Vol. 7, No. 11, 1937,

Method of construction described.

99, "Low-Cost Inqjrovement of Streets." V, E. Best. Pennsylvania Road Builder, Vol, 10, No, 11, 1937.

Street sections withstood winter without any repairs. 100. "The Story of Calcium Chloride as a Road Binder." Part I - Introduc­

t i o n , Part I I - History, Occurrence, Manufacture, and U t i l i t y , Part I I I - Deliquescence and Hygroscopic Properties, Part IV -Surface Tension and Vapor Pressure. Calcium Chloride Assoc. Kews, May-June, July-August, September-October, November-December, 1937.

T i t l e expljuiatory,

101. "Role of S o i l Binders and Aggregates i n S o i l S t a b i l i z a t i o n , " C. A. Hogentogler and J. A. Kelley. Proc. Am. Road Builders Assoc., 1937.

Whole theory of s o i l s t a b i l i z a t i o n based on two facts: (1) a l l ' s o i l mixtures common f o r road usage are stable a t some moisture

content, (2) moisture i n stable roads i s more adhesive than _ free water and s t a b i l i t y depends upon thickness of adsorbed moisture f i l m s .

102. "Road S t a b i l i z a t i o n . " L. L. Allen. Proc. Am. Road Builders Assoc., 1937.

I n 1932 survey showed 13 states and D i s t r i c t of Columbia had laboratories capable of performing s o i l c l a s s i f i c a t i o n t e s t s . Two years l a t e r 27 state highway depairtments were equipped. Reviews Minnesota experience.

103. "Stabilization with Aggregates, BindeivSoil and Calcium Chloride." F. Burggraf, Proc, Am* Road Builders Assoc., 1937.

General review a r t i c l e on a l l phases of subject,

104. "Plant Mixed Materials and Pulverization of Clay." L. C. Stewart. Proc, Am, Road Builders Assoc., 1937.

Reviews entire f i e l d of plant mixed s t a b i l i z e r s ; types of plants, construction of plants, mixers, etc,

105. "Building a Stabilized Gravel Road." Improvement B u l l e t i n , Vol. 85, No. 8, 1938.

Stabilized gravel road b u i l t under contract. Methods given.

47. 106. " I i ^ r t a n t Details i n S t a b i l i z a t i o n with Calcium Chloride." B. C.

Tiney. Public Works, Vol. 69, No. 1, 1938. Trend of design of stabilized mixtures has been to reduce pro­portion of binder s o i l and thereby lower Plastic Index of mix­tur e . Cheuiges i n practice developing.

107. "Pennsylvania U t i l i z e s Local Materials i n State-Wide Road St a b i l i z a ­t i o n . Construction Methods and Equipment, Vol. 20, No. 3, 1938.

Testing laboratory has set up and w r i t t e n specifications f o r f i v e general designs of mixtures. General construction meth­ods.

108. "Surface Consolidation €Lnd Dustless Maintenance of Gravel Roads." L. L. Bateman. Better Roads, Vol. 8, No. 4, 1938.

General practice of surface consolidation. Most f a i l u r e s be­cause of i n s u f f i c i e n t mixing on surface of road.

109. "Residential Street Improvement." John H. Ames. American City, Vol. 53, No. 4, 1938.

Low cost methods required commensurate with t r a f f i c . Details of experience given.

110. "Consolidating Gravel County-Road Surfaces." Better Roads, Vol. 8, No. 5, 1938.

Michigan experiments on gravel road maintenance. General practice.

111. "Consolidation of Roads with Calcium Chloride." Canadian Engineer, Vol. 74, No. 23, 1938.

Br i e f description of practice.

112. "Stabilized Base f o r Black Top Road on U. S. 10." Michigan Roads and Construction." Vol. 35, No. 23, 1938.

Base course I s calcium chloride clay s t a b i l i z e d gravel mixed i n plant as required by Michigan specifications.

113. "Production and Use of Stabilized Maintenance Material." J. C. Black. Roads and Streets, Vol. 81, No. 6, 1938.

Clay and admixture mixed with gravel at plant and used i n re­pair of shoulder ruts a t edge of concrete.

114. "Sprinkling of Stabilized Roads Proves Success." B. R. Downey. Michigan Roads and Construction, Vol. 35, No. 31, 1938.

Sprinkling helps keep gravel trunk l i n e s i n good condition during summer.

115. "Many Coimty Roads Stabilized with Calcium Chloride." Contributors, A. M. WilHams, Otto Hess, and A. L. Burridge. Michigan Roads and Construction, Vol. 35, No. 42, 1938.

Comments of three county engineers a l l favorable t o calcium chloride s t a b i l i z a t i o n .

r 48.

116. "Betterment i n Maintenance by P a r t i a l S t a b i l i z a t i o n . " B. C. Tiney. Public Works, Vol. 69, No. 10, 1938.

Methods of surface consolidation described. 117. "Frost Action i n Stabilized S o i l Ifixtures." H. F. VJinn. Proc. High­

way Research Board, Vol. 18, Part I , 1938. Presentation of experimental data on the r e l a t i o n of f r o s t ac­t i o n i n stabilized s o i l mixtures t o gradation of s o i l mixtixre, type and percentage of admixture, and moisture content at begin­ning of freezing period.

-IL8. "Use of Calcium Chloride i n Road St a b i l i z a t i o n . " "Symposium". Con­t r i b u t o r s : C. F. Briggs, F. Burggraf, B. R. Downey, J. Elleman, C. A. Hogentogler, J r . , J. A. Knight, and H. D. Wilford. Proc. Highway Research Board, Vol. 18, Part I I , 1938.

Complete series of short a r t i c l e s on a l l phases of use of c a l ­cium chloride i n s t a b i l i z a t i o n .

X 119. "Prevention of Detrimental Frost Heave i n Sweden." G. Beskow, Proc.

Highway Research Board, Vol. 18, Part I I , 1938. T i t l e explanatory.

120. "Stabilized Roads." Geo. J. Cormier. Proc. Am. Road Builders Assoc., 1938.

S t a b i l i z a t i o n experiences i n Brown county, Wisconsin. 121. "Developments i n S o i l S t a b i l i z a t i o n . " C. A. Hogentogler. Proc. Am.

Road Builders Assoc., 1938. Qiq}hasis on s t a b i l i z a t i o n of subgrade, which i s one of the most iiq>ortant problems i n road building.

122. "The Gradlng-Density Relations of Granular Materials." Prof. D. M. Burmister, Columbia University. Proc. Am. Soc. f o r Testing Ma­t e r i a l s , Vol. 38, Part I I , 1938.

T i t l e explanatory.

123. "Current Developments i n Stabilized Gravel and Crushed Stone Roads." Ernst Lieberman. F i f t h Ann. Mineral Industries Conference, State Geological Survey, Urbana, I l l i n o i s , Circ. No. 23i 1938.

Three applications of calcium chloride recommended; of 3/4 per sq. yd i n May, July, and September.

124. "Calcium Chloride Road Construction." J. E. Tremayne. Canadian En­gineer, Vol. 76, No. 2, 1939.

An outline of a practicsJ. and economical method of providing adequate surfaces f o r gravel road t r a f f i c .

125. "Stabilization by Use of Chemicals." R. B. Traver. Twenty-fifth Ann. Road School, Purdue University, 1939.

General review of f i e l d of s t a b i l i z a t i o n .

49.

126. "Gravel-Road Surface Wear lieasured i n Michigan Investigations." R. S. Swinton. Better Roads, Vol. 9, No. 1, 1 9 3 9 .

Under closely controlled conditions calcium chloride stabilized road showed 36 per cent wear compared to 100 per cent f o r an untreated gravel road.

127. "Production of Stabilized Gravel." Construction Methods and Equip­ment, Vol. 21, No. 2, 1939.

Note that s t a b i l i z e d mixture i s being produced at rate of 90 eu. yd. per hour i n plant.

128. " S t a b i l i z a t i o n , Surface Consolidati<jn and Dust Laying." Herman M i l l e r . Dowflakes. Vol. 1, No. 1, 1939.

Definitions of d i f f e r e n t types of s t a b i l i z a t i o n and use of c a l ­cium chloride i n both.

129. "Calcium Chloride f o r Streets i n Belgian Congo." American City, Vol. 54, No. 5, 1939.

Brief report on use of calcium chloride.for s t a b i l i z i n g streets..

1 3 0 . "Field Tests Reveal Calcium Chloride Increases Density and Structural S t a b i l i t y . " F. Burggraf. Calcium Chloride Assoc, News, May-June, 1 9 3 9 .

Stabilized mixtures containing calcium chloride a t t a i n same de-.gree of compaction with less than half as much r o l l i n g as un­treated mixtures.

1 3 1 . "Slag and Calcium Chloride GtLve Good Base f o r Black Top Surface." E. L. M i l l s . Public Works, Vol. 70^ No. 6, 1939.

Main street of Deersville, Ohio prepared f o r black top surface by calcium chloride s t a b i l i z a t i o n .

1 3 2 . "Consolidation of Gravel Roads." Surveyor (England), V. 9 6 , No. 2477, 1939.

Standard procedures of calcium chloride s t a b i l i z a t i o n i n Quebec, Canada.

1 3 3 . "Calcium Chloride i n Construction." Engineering Journal, Vol. 22, No. 8, 1 9 3 9 .

Physical and chemical properties of calcium chloride and general methods of use i n construction.

1 3 4 . "Good Surfaces from Cheap Local Gravel." Paul E. SLasgow. Better Roads, Vol. 9, No. 11, 1939.

U t i l i z a t i o n of cheap l o c a l gravel i n calcium chloride s t a b i l i z a t i o n .

1 3 5 . "Stabilized Gravel Roads i n Muscatine County, Iowa." F. P. G. Halbfass. Public Works, Vol. 70, No. 11, 1939.

Description of construction.

50,

136. "Studies of Water-Retentive Chemicals as Admixtures with Nonplastic Road Building Materials." £. A. W i l l i s and C. A. Carpenter. Public Roads, Vol, 20, No. 9, 1939.

A r t i c l e oi\ use of outdoor c i r c u l a r track t o determine the ef­fect of chemicals including calcium chloride on non-plastic granular mixtures both with and without a t h i n bituminous sur­face treatment.

137. "Field Tests on Shearing Resistance?" F. Burggraf. Proc. Highway Research Board, Vol, 19, 1939.

Tests with f i e l d shearing apparatus correlated with tests on ctilcium chloride stabilized road.

138. "Economics of S t a b i l i z a t i o n w ith Cidcium Chloride." "Symposium". Contributors: W. F. Abercrombie, A. L. Brown, F. L. Brown, H. F. Clemmer, G. Farnsworth, P. Glasgow, J. E. Moreland, and R. M. Whitton. Proc. Highway Research Board, Vol, 19, 1939-

Symposium on subject of t i t l e .

139. "Use of Calcium Chloride i n Road St a b i l i z a t i o n . " John H. Elleman. Proc. Am. Road Builders Assoc., 1939.

General a r t i c l e of review nature on use of calcium chloride i n s t a b i l i z a t i o n .

140. "Soil S t a b i l i z a t i o n . " Victor J. Brown and others. Ca.llette Pub­l i s h i n g Co., 1939.

Reprinted from s i x 1938 issues of Roads and Streets. Gen­er a l principles of s t a b i l i z a t i o n .

141. "Fundamentals of Road and Subgrade S t a b i l i z a t i o n . " W. R. WooUey. Twenty-sixth Ann. Road School, Purdue University, 1940.

T i t l e explanatory. 142. "Stabilized Base f o r County Roads," Paul E. Glasgow. Contractors

and Engineers Monthly, Vol. 37, No. 1, 1940, Procedure described i n conveirting t r a f f i c bound surfaces or more heavily traveled roads i n t o low cost, more stable sur­faces i n V/ayne county, Ohio.

\J 143. "A Survey of the Frost-Heaving Problem." J. 0. Osterberg. C i v i l

Engineering, Vol. 10, No. 2, 1940. Review on mechanics of flrost heaving.

144. "Gravel Bases f o r Bituminous Surface." J. G. Schaub. -Twenty-sixth Ann, Highway Conference, University of Michigan, 1940,

Michigan adopted practice of placing bituminous surface t r e a t ­ment on newly l a i d gravel bases or reconstructed old gravel roads. Procedures presented i n construction of calcium chlo­ride stabilized bases.

145. " S o i l S t a b i l i z a t i o n . " C, A. Hogentogler. Twenty-sixth Ann. High­way Conference, University of Michigan, 1940.

General discussion on volvmie changes i n s o i l s with moisture.

51. 146, "Evolution of Low-Cost Roads." W. H. Root. Better Roads, Vol. 10,

No. 6, 1940. Procedure i n s t a b i l i z i n g loose gravel surfaces.

147, "Chemical Treatment of Chert-Gravels f o r Use i n Base-Course Construc­t i o n . " E. A, v a i l i s and P. G. Smith. Public Roads, Vol. 21, No. 4, 1940.-

The use of admixtures to chert gravels for base course construc­t i o n tested by means of a laboratory c i r c u l a r track.

148, "Frost Damage on Roads." H. H. Ravn. (Denmark), Highway Research Ab­stra c t s , No, 71, 1940. Highway Research Board. ^

Types of f r o s t damage described and methods of prevention pre­sented.

1/̂ 9. "Effect of the Chemical Properties of S o i l Fines on the Performam of Soil-Aggregate Mixtures." Paul Rapp and Jacob Mizroch. Pul̂ . Roads, Vol, 21, No. 10, 1940.

Data presented showing the relationship of chemical properties to physical properties and the behavior of roads.

150. "Calcium Chloride Surface Consolidated Roads," J. H, Elleman. Proc, Highway Research Board, Vol. 20, 1940.

Description of construction and maintenance of calcium chloride stabilized roads,

151. "Field Tests and Their Application t o the Design of Stabilized S o i l Roads," F. Burggraf, Proc, Am, Road Builders Assoc, 1940,

Describes apparatus designed t o t e s t resistance t o shear of components making up a road structure. Results of tests given,

152. "Plant Control of Stabilized Mixtures," F, R. Olmstead. Proc. Am. Road Builders Assoc., 1940,

Con^lete a r t i c l e on use of plant mix materials i n Michigan.

153. "Plant Mix Stabilized Aggregate f o r the Michigan Secondary Road System," F. R. Olmstead, Better Roads, Vol. 10, No, 1 , Jan, 1940,

Reviews the methods used t o assure the uniform production of stabilized materials,

154. "Road Base Construction of Graded Aggregate i n Wisconsin." A. Smith, J r . Dowflakes. Vol, 2, No, 6, 1941,

General account of work i n Vfisconsin.

155. "Calcium Qiloride f o r Base S t a b i l i z a t i o n . " George Uemmerick. ' Canadian Engineer, Vol. 79, No. 3, 1941.

Bri e f review of general practice.

156. "Developanents i n the Construction Field." C. M. Hathaway. Twenty-eighth Ann. Conference on Highway Engineering, University of I l U n o i s , 1941.

T i t l e explanatory.

52.

157.

158,

159.

160.

161.

162,

165.

"A Rational Approach to the Secondary Road Problem." • E. H. N\inn. Crushed Stone Journal, Vol. 16, No. 3, 1941.

Procedure based on s o i l t e s t s , conditions of temperature', hmnidlty, and t r a f f i c .

"Steams County Experiments with Calcium Chloride Stabilization.," John S. Schmitt. Public Vforks, Vol. 72, No. 6, 1941.

General account of practice.

"Soil Control i n Consolidated Maintenance." B. R. Doimey. Proc. Highway Research Board, Vol. ZL, 1941.

Detailed procedures presented of actual construction and main­tenance of t h i s type of road. Stress l a i d on systematic or­ganization.

"Surface S t a b i l i z a t i o n i n DeKalb County, Indiana." W. T. Van Auken. Proc. Twenty-seventh Ann. Road School, Purdue University, 1941.

General account of treatment.

"A Field Investigation of Low-Cost Stabilized Roads." D. J. Belcher. £kiglneerlng B u l l e t i n of Purdue University, Research Series, No. 81, Vol. 25r No. 2 a , 1 9 a .

Field tests supported by laboratory eaqieriments involving use of several types of admixtures. Methods of construction pre­sented.

"Gravel Road St a b i l i z a t i o n with Calcium Chloride." L. B. G r i f f i n . Proc. Twenty-eighth Ann, Road School, Purdue University, 1942.

Method of construction i n Johnson county, Indiana.

"What Has the Frost Damage of Last Year Tauftht Us?." L. Casagrande (Germany). Highway Research Abstracts, No. 86, 1942. Highway Research Board.

T i t l e explanatory, "Modernisation i n Minnesota: Consolidation of Gravel Surfaces i n

Steams County." H, V. Pehrson. Better Roads, Vol. 12, No. 4, 1942.

High maintenance costs of gravel roads lead to surface consol­idation with calcium chloride.

"The Technique of Road St a b i l i z a t i o n . " H. M i l l e r . Dowflakes, Vol. 4, No. 4, 1942.

Presents chart t o determine quantity of clay required t o give a certain Plastic Index when combined with a given aggregate-.

"Subgrade Protection and Winter Paving on Access Roads." E. H. Nunn. Calcium Chloride Assoc. News, Vol. 8, No. 4, 1942.

Calcium chloride prevents freezing of subgrade, thaws frozen earth and protects concrete i n Maryland. This f a c i l i t a t e d con­struction irtien faced with problem of cold weather concreting and protection of subgrade from freezing between time grade was prepared and placing of concrete.

5 3 .

1 6 7 . "Stabilization Today i s Basis f o r Future Roads." H, M i l l e r , P. Caslin, and K. Goetz. Dowflakes, Vol. 4 . No. 5t 1 9 4 2 .

General report on method of construction i n St. d a i r county, Michigan.

1 6 8 . "Stabilized Bases Mixed at P i t . " M. E. Amstutz. Better Roads, Vol. 1 2 , No. 9 , 1 9 4 2 .

Binder s o i l added to gravel at p i t before going to crusher. Method of construction given.

6 ^ . "Preventing Detrimental Frost Heaving." Penrisylvania Road Buildeg. Vol. 1 5 , No. 9 , 1942 .

Calcium chloride affords protection under tests at teo^eratures down to 10 degrees below zero.

"Inexpensive Treatment f o r Frost Boils Helps Prevent Costly Pavementjl fjj^ Repairs." Engineering and Contractors Record, Vol. 55» No. 4 2 , C^l^^\ 1 9 4 2 . ]

Method of using calcium chloride i n treatment of asphalt heaves / and b o i l s . y

171 r '~"Calcium Chloride Nomographs." D. S. Davis, i n d u s t r i a l and Engineer­ing Chemistry, I n d u s t r i a l Edition, Vol. 3 4 , No. 1 , 1 9 4 2 .

Nomographs presented f o r calculation of properties of calcium chloride solutions by hydrometric methods of analysis.

72) "Use of Calcium Chloride i n Subgrade Soils for Frost Prevention." F. 0 . Slate. Proc. Highway Research Board, Vol. 2 2 , 1 9 4 2 .

Studies of migration of calcium chloride solution through sub-grade of t e s t road. Effect of additions of calcium chloride on freezing of laboratory specimens.

7 3 ) "Thawing Frozen Subgrades." B. P. Thomas. Calcium Chloride Assoc. News, Vol. 9 , No. 1 , 1 9 4 3 . \

Application of calcium chloride, from two t o six l b . per s ^ yd. w i l l d e f i n i t e l y thaw subgrades and base course matertals so work can proceed.

1 7 4 . "Stabilized Crushed Rock Surfaces." J. E. Heirzog. Better Roads, Vol. 1 3 , No. 2 , 1 9 4 3 .

Method of construction and costs presented f o r using crushed limestone aggregate treated with calcium chloride; Steele county, Minnesota.

(£75^) "Frost Heaving i n Soils and Modem Road Construction." A. Schmid. Highway Research Abstracts, No. 9 9 , 1 9 4 3 . Highway Research Board.

Since expansion of s o i l caused by f r o s t heaving i s considerably^ greater than can be accounted f o r by freezing of water alone i t must also be due t o the a i r freed by the drop i n temperatwe. Remedy suggested.

54.

"Frost Damage." L, Schaible (Germany). Highway Research Abstracts, No, 99» 1 9 4 3 . Highway Research Board.

T i t l e ejqplanatory,

hniX'^'^ Rate of Freezing i n S o i l and I t s Dependence on the Thickness of " ^ ^ ^ the Snow Layer." H, Geslin (France). Highway Research Abstracts, X No. 99, 1 9 4 3 . Highway Research Board,

Observations showed that a snow layer or blanket of 6.24 inches was necessary to completely prevent freezing of underljring s o i l .

1 7 8 . "Stabilized Soil-Bound Surfaces with Calcium Chloride as an Admixture." G. C. Blomquist. Michigan State College Engineering Experiment Sta^ t i o n . Project No. 71, B u l l e t i n No. 97, 1943.

Circular track tests used to investigate materials both treated and untreated with calcium chloride.

1 7 9 . "Michigan's Practice i n Gravel S t a b i l i z a t i o n . " B. R. Downey. Roads and Streets, Vol. 86, No. 6, 1943.

T i t l e explanatory. 180. "A S t i t c h i n Time." H. M i l l e r . Dowflakes, Vol. 5, No, 4, 1943.

General i n f o m a t i o n on construction and surface consolidation.

181. "Maintenance i s Negligible on Surface-Consolidated Roads." J. S. Schmitt. Calcium Chloride Assoc. News, Vol, 9, No, 4, 1943,

Stearns county, Minnesota reports on maintenance.

182. "Minnesota County Reduces Maintenance Costs." A. F. Stegner. Cal­cium Chloride Assoc, News, Vol, 9 , No, 4 , 1943,

Fillmore county consolidates limestone surfaces with calcium chloride and gets more durable roads, also reducing maintenance blading by 75 per cent,

183. "Stabilized Base Gives Surprising D u r a b i l i t y to Low-Cost Surface." Calcium Chloride Assoc. News, Vol. 9 , No. 4 , 1943.

Success of a t a r and asphalt emulsion coating on a calciiun chloride stabilized base attributed to the s t a b i l i t y of the base.

184. "Determining the Proportion of a Well-Graded Road Gravel," J, Shaw. Road and Road Construction (England), Vol. 21, No,^49, 1943.

T i t l e e3q)lanatory.

185. "Movement of Calcium Chloride and Sodium Chloride i n S o i l . " Charles Slesser. Proc. Highway Research Board, Vol, 2 3 , 1943.

Experimental data presented on the migration of chemicals i n s o i l emd the reduction of flrost heave by the use of chemicals.

186. "Granular Stabilized Roads." Wartime Road Problems No. 5> Highway Research Board, 1943,

A "short course" on granular stabilized roads.

55.

187. "Factors Related to the Design of Stabilized Mixtures." F. R. Olmstead. Journal of Asphalt Technology, Vol, 2, No, 4, Aug. 1943.

Contains numerous shortcuts i n the p r a c t i c a l design of sta­b i l i z e d mixtures and stresses importance of material inven­t o r y , s o i l survey maps and a e r i a l photography.

188. "Laboratory Tests on the Effect of Stone Content on the Conqjaction of S o i l Mortar." L. Maddison. Roads and Road Construction, Vol. 22, No, 254, 1944, (England),

Tests Indicate that course material Impedes compaction of s o i l mortar.

"Caldiun Chloride Treated Roads Guard Against Spring Break-Up," Calcium Chloride Assoc. News, Vol. 10, No, 3, 1944.

Calcium chloride treated roads less than one tenth as susi ceptible to spring breakup as untreated roads.

190. "Stabilization and Maintenance of Roads f o r Heavy Armored T r a f f i c , " Major Ben H, Petty. Proc, Highway Research Board, Vol, 24, 1944,

Describes the successful use of calcium chloride with large sized crushed stone to provide surfaces t o withstand tank t r a f f i c .

191. "Granular Stabilized Base Construction of Access and Relocation Roads by Tennessee Valley Authority." F, W, Webster and F, H. Kellogg. Proc. Highway Research Board, Vol. 24, 1944.

Method of quick construction allowing heavy t r a f f i c i n short period of time,

192. "An Exanple of Gravel Base Construction I n Maryland Under Heavy T r a f f i c Conditions." J. E. Wood, Proc, Highway Research Board, Vol. 24, 1944,

Reviews construction procedure on a bank-run gravel stabilized access road.

193. "Mechanics of Calcium Chloride Treatments," J, F. Trlbble, Proc, Highway Research Board, Vol. 24, 1944.

Describes the function of calcium chloride i n the solution of the troublesome problem caused by the heavy r o l l i n g of the bottom layers of base courses containing too l i t t l e moistxire f o r adequate compaction,

194. "Con9>actlon of Subgrades and Snbankments." Wartime Road Problems No. 11, Highway Research Board, 1945,

A "short course" on s o i l compaction.

Table 6 SOIL TEST COBSIiUiTS. SOIL COHDITIOB, TBATFIC ISD fDllPIBG

(SOUB Mta rrca Ssaplea f r a OeUU Study SeeUons)

Sou Condition 24 Hour Traffic Truck Azla Lo^da In Froa Recconalaaanea

PuBPlna Jolnta and Craeke (Per Cent) Text- Sou Hater ^

P.H.A. Grarel oral Content (Jt) Range of Total Total Kipa (CunulatlvaJ Snrvey for Project Project Sou SoU and CeU- SoU At Depths Shorn Density Ho. No. Over Over Over Over filass <;lasa Class Class Class Claaa Ho. Bo. L.L. P.L. P.I. F.M.B. C.M.E. S.L. Group Sand SUt Clay olds Type 0-1" 2"-4" 5"-8" (p.e.f.) Vehicle* Trucks 12 U 16 18 1 2 3 Total 1 2 3 Total

Froa Teat Sections Only s C l

239BS 2391(2) 239C 220iS 36DS

564(2) (3) 5*

(0-5") U*

(5"-10")

1* 37 16 21 21 35 U JU6 U 56 30 12 SIC 21 21 21 104-106 1625 377 217 154 63 12 5.6 1.5 3 64 22 42 35 31' 15 A-6-7 35 26 39 24 C - - - - 1017 236 137 97 40 8 5.6 1.5

4 46 19 27 30 27 14 30 36 34 19 C ' 34 24 31 100-104 6 U S U19 818 580 238 47 16.6 6.9 13 52 22 30 29 27 21 A-7-6 29 24 47 33 C - - - - 2620 524 256 136 90 27 10» 46 23 23 35 30 20 i-7 9 6a 31 6 .SiC 26 25 26 96 3740 748 367 196 130 40 21.0 7.6

0.2 7.3 28 Severe Puaping (Ho Count Made) - 23.5 4

Severe Puaping (Bo Count Hade) 1.6 30.2

28

46 17 63

25 17

33 20

41 34

34

31

15 A-7 15 A-6

27

52

26 30

47 18

29 9

SIC SL

27 27 22 18

147CS -OS 156 42 60AS 23 83 Average a l l Soils 53

2391(2) 2 56 121BS 12» 30 220AS 7» 46 5US li Ext. . 8» 38 36DS 9» 45 51CS U» 39 56A(2)

(3) 6 35 (&-6')

n 15 47 (6°-U") *

n 15 64 486A (0-4")

(2) 17 17 (4"-U")

B 17 29

240A 20 34 269B 22(07) 35

• 22(47) 39 22(87) 32

78BS 24 52 7SAS 25 33 371C 34 20 28or 35

a 36 31 0 37 •37

2l(I)eopj3S* -39 36 244A 1-6 28

I I 1-C 33 n 2-6 25 n 3-6 23 R 4-6 20 N 8-6 35

5-6 28 11 7-C 33

B-8-A (4)1D-C 36

31CS 12-6 32 394S 13-C 40 U7CS -DS u-c 35

Av. (All Solls)34

24 38

IS

45 33 55

26

U

20 A-7 22 A-7

10 18

56 11

34 19 71 57

*v. C, SiC, sm. i Cl 37

Av. for Sol's «lth 50$ S

& Cr. 30

25 28 36 32 13 23 32 45 28

20 36* 37 30 15 A-6-7 25 35 40 24 20 10 26 & 20 A-4 15 63 22 10 25 21 39 29 19 A-7 8 50 42 24 13 25 21 18 13 A^ 58 19 23 20 22 23 32 29 19 4-7 U 61 28 12

19 20 28 24 17 A-7-6 22 53 25 10

19 16 28 21 21 A-7-6 72 15 13 7 21 26 34 29 18 A-7-2 62 17 a 13 34 30 50 40 22 A-7 34 17 49 a 12 5 16 U 12 A-1-2 73 16 U 4

18 U 23 24 18 A-4 21 47 32 17 18 16 28 16 18 A-7-2 58 16 26 16 16 19 24 22 U A-6 61 U 25 15 17 22 27 24 U A-6 57 13 30 18

15 17 22 22 13 A-2-6 66 U 20 U

21 31 33 31 17 A-&-7 67 10 23 15

20 13 25 25 15 A-2 80 10 10 6

13 7 18 13 U 4-2 67 13 20 12 HP HP 27 5 - A-3 90 1 9 5 18 13 26 19 17 A-2 88 5 7 4 19 18 26 22 18 A-7 18 52 30 U HP HP 25 5 . A-3 92 2 6 4 16 20 24 23 15 A-6-7 34 38 28 13 16 12 22 20 16 A-2-4 45 28 27 U 19 U 27 19 19 A-2-7 52 19 29 19 15 10 21 18 U A-2 54 19 27 U U 9 19 15 13 A-2 54 21 25 13 13 7 17 15 13 A-2 58 21 21 8 21 U 32 21 15 A-2-4 49 15 36 27 16, 12 22 17 U A-2-7 49 22 29 16 20 13 27 24 19 A-4 30 40 30 U

a 15 28 25 22 A-4 10 23 10 21 U 27 19 22 A-4 25 61 U 7 22 18 32 25 20 A-7 10 a 29 16

18 17 24 22 18 A-7-4 19 61 20 8

18 16 27 21 17 47 29 24 U

19 18 30 25 18 25 46 29 15

15 15 24 18 15 67 U 19 U

C 23 SiCl 18 SiC 24

SCI 17 SlCl 23

.SiCl a

S I a

s a c SI

c SCL Or.SCL Or. ac Or. SCL Or. SCL SI SCL S Gr.S SIC S Cl

Cl SCL SCL SCL SCL C CL Cl SlCl SIL SlCl SiCl

22

26 20 28 18 26

a a

18

u u

16

15 15 18 9

18 9

17 16

39

n U 49 23 26 28 25. U A-7 25 40 35 20 C - - 30 240A 18 29 16 13 22 a U A-4 43 32 25 9 Cl - -n 19 28 17 u a 21 15 A-4 29 40 31 10 C - 19 20 58AS 26» 64 30 34 38 35 19 A-7 13 28 59 39 C a 29 28 339CS 27» 65 27 38 39 35 15 A-7 27 31 42 25 C 38 38 29 231CS 28 76 30 46 45 39 23 A-7 a 13 63 48 C 32 31 34

II 29* 64 a 40 43 34 19 A-7 20 18 62 a C 20 27 30 324AS 30» 58' i7 31 38 34 17 A-7 15 30 55 27 C 30 33 34

R 31» 59 28 31 47 34 17 A-7 18 a 61 45 C a 27 -313AS 32 60 35 25 47 36 a A-7 23 18 59 47 c - - -(Heop.) 33 69 48 a 56 40 23 A-7-5 22 12 66 53 c - - -

24(BS 6e 48 23 25 30 29 20 A-7 8 40 52 32 c - - -B-8-A(3)llc 40 a 19 29 27 20 A-7 11 65 a 10 SiCl - - -

SlC- - -

c a 39 AO

28 28

43

19

15 18 9

19 20 23

a

20

85-86 6575

(107-U5 (

95-98 85-94 91-92 89- 94 90- 93

89

2185

4610 3030 1415

n

970

1825 3310 UOO 4250

2820 m o

1525

507

844 554 259 n 203

334

606 " 230

loa

680 203

878 622 255 50 a.5 2.8 0.1 27.4

292 207 85 17 4.7 1.7 6.3 12.7

437 318 159 287 209 104 134 98 49

30 20 9

3.5 6.4 2.4

3.3 2.2 0.2

0.3 7.1 0.6 9.2

94 47 19 12 Severe Puaping (Bo Count Hade)

173 126 63 12 27.2 16.7 8.3 52.2 3U 229 U5 106 53 22 UO 76 36

92 49 23 104 76 38

22 38.0 0.2 - 38.g M Severe Funping In

Some Areas (Ho Count) 7 Moderate Puaping (2)

(«o Count Hade) 4 SUght Punplng (3)

(Ho Count Hade) 7 9.6 6.2 1.9 17.7

30 94-97 604 285 193 90 19

26 103-108 1017 236 135 97 40 8 Hone 20 106-UO a75 495 242 129 86 2i It

31 90-95 2620 s a 256 136 90 27 m

16 lU-114 1200 240 U7 62 a 12 •

27 93-96 3740 748 367 196 130 40 B

22 101-108 950 190 93 50 33 10 B

23 104-107 6575 1525 878 622 255 50 11

109 97

( (109

1920

a 8 5 2975

2870 2880

U5 256 182 75 15

507 690

525

527

292 207 398 282

272 198

274 200

85 17 U6 23

99 19

100 19

95-97

UOO 220(A) 108 58 38 12 H

550 110 54 29 19 6 fl n a n R n R • • a H R n fl I I

2230 U6 218 116 77 23 D R n R a n R R

U25 298 137 68 28 18 R R I I n H m n R R D n n H a It H • n n R 0 n H n a u H n fl a D R n n n n

UOO 230 n

106 II

53 R

22 n

u . 11

It «

102-105

5740 1383 189 102 48 9 a

1730 a 7 57 31 15 3 1660 400 54 29 U 3 B

2820 e80 92 49 23 4 B

2370 516 a 9 138 68 17

2397

2355

530

502

165 91 54 15

273 184 85 19

28 30 - 58

30 54 - 84 20 39 - 59

B B •

- - 4 4 7 - - 7 94 _ _ 94 15 30 6 51 17 57 9 83 46 - - 46 45 32 13 90 47 3 - 50 Bo Count Made Bo Count Hade

40 20 10 700.)

32 32

(1) lOi of Joints and cracks in i500 f t . sections pumped. (3) Slight pumping at comer break in short cut sections.

'Tested for consoLiJation.

Distribution estimated, (d) Pumping over small area at lo» point In grade there shoulders »ere high. (4) Truck traffic and distribution estimated. (5) Reconnaissance count for combined projects 231 GF and C.

TABLt 2. WARTIME HAULING FROM PERTH AMBOY TO COLTS NECK Tobvlahofi frliowiii^ ni« prtfnt tomdittom of p a v t m « n t ( O c r N 4 4 ) and types of ftoilft and Mbbotoa IN voneuft crma% ev«r which hcovy warhmo haalitia w o t dona, durinq lh« panod 0«c, 1449 ro Auq I 4 4 A Tha vnladan waiqhH of rha rrvcka vaad wara l i s o e * (2 o i i a a 2 4 6 S 0 * ( t a i l a f t ) i 2 1 0 3 0 * M a i l a a ; Tha ovaraaa wti^ht of toadad rruck* wo* approtimmtttf 60009* Tna aaMmatad numbar of foadad Irvcfc* (MMO*) pottinq ovar rni» pavamant par day, dunnq thit parted wa» 212 Hi i» HM* HI addition re o nermal daily fraffie of 300 Frveliv

Rou^« U u i CMCMt. •bint SWUMM

T h I c k M t t L o c a h . n Pay f c m c n t C o n d i t i o n SMI,I« & i e v « M m AM Ivftii-X Snallar

S.& L L n rtit Commonto f u n t o o , o thcrwi ic notad. Mmpta , ara of nat iv . aoil from inmadiataly un4af ttia povomanf ) Rou^« U u i

CMCMt. •bint SWUMM T h I c k M t t M i l « » 6 u « r a l Almoin. r . u l t i n * C r a c k t N l t ^\• r i " 4' * 4 * I0 ' 40 • . 0 200 05 • « • . 001 •» - •

S.& L L n rtit Commonto f u n t o o , o thcrwi ic notad. Mmpta , ara of nat iv . aoil from inmadiataly un4af ttia povomanf )

4hS5 n»6 2 7 ) t n o l l m t Ma No 2S 100 47 44 1 0 8 04 01 270 N P NP 28 4&,SS • • • • 3 i « • - • . 26 160 4 4 16 70 21 22 10 3 0 2 0 LO 268 MP NP 21 L40 34

4 1441 • - i o o • • • 17 toe 46 45 • 1 7 ) 6 ) 41 21 1) 12 6 3 275 20 0 11 176 17 Samola of ftubbota wiatarlal 4- • • 4.M • • 28 too 47 44 41 08 67 44 35 32 II 4 2 71 21 1 22 167 21 4 • • • A.«e • • - • 24 ISO 44 46 47 76 21 16 15 6 2 170 HP N.P 16 17) 14 Sawlola of 0.11 u a d a r l y i n . ttn 4* tayar .tiovvn o b o v . . c t tandino to al Itatt 4' balew tha pavamawl owrfaca

4 A l t a n u t . • N . Sakkau 7 27 R l built i o v t r t S . v « r « texrt 100 44 44 16 86 37 17 2 75 S6 1 23 157 25 • • • 7 * 7 Poor • t 4 100 44 11 17 71 32 26 1 4 210 16 NP 17 176 17 • * • 7 8 4 Forr Pirababli F t w 5 100 41 44 16 76 12 4 2 2 211 MP NP 25

• • • 8^15 - • • 6 IOO I t 66 7 6 3 2 211 N P N P 16 157 26 • • • - • 8 4 0 RBor J«»or . S««ara Monv 7 100 16 86 64 55 13 S 273 26 5 11 171 20

• • • • •111 Rtbui lr 5«v«r« ^ c i w r . & .vcr ( 152)44 100 41 14 67 72 20 S SI 7 31 141 S 3 * • 4 I S - I - 8 i « a 46 4 2 8 3 74 75 64 65 54 46 16 4 277 30 4 17 175 22

• * • • • 4 ) 6 - - - ) K O 46 4 6 42 84 01 77 61 JX 61

47 21 10 275 27 4 15 16) 21 , . . . . • - 4 7 5 - - - - 4 100 48 4 4 41 • 6 • ) 75

JX 61 57 30 16 281 4 0 10 14 166 41

3 4 ) e c 1 M24 • l« 114 • - • - 152 4«0 100 44 4 6 10 73 ) 8 14 41 16 I S 144 22 Vary biutty yuwiotna graa aeil layar at laaU > Ihicii • • • • I I 18 Indtrmill H i n . r F«» 10 46 1 6 4 5 45 4 ) 40 67 80 50 17 16 10 6 274 NP NP 14 165 20

• • • 1166 - OMWIHI - Varr F.W 11 100 44 41 46 14 6 4 15 1 1) 5 3 27) NP NP IS 164 20 • - I t 16 n.builr S«v.r< S«wor. S a v o r . 12 100 44 44 46 47 45 80 55 24 26 II 3 276 27 2 14 111 21 • I t i ) G o o d Minor, ifonr No Vbn Fiw S - l 100 44 48 6 2 II

* • lt«) P a i r Indofintt. frtinar Few 1) IOO 44 1* 'to 4 ) 1' 80 76 30 26 II 4 270 11 NP 14 111 20 1 ) 4 ) No No Naoliaibia 14 100 48 47 46 45 45 44 65 37 II 10 6 2 275 NP NP 16 164 22 • • • • 14.02 Fa i r Indtfinit. Minor Faw 1$ 160 47 1 » 64 64 77 73 66 31 20 12 7 262 26 18 115 22

• • • i«ia fool Ocfinit. i - * Many 16 1 100 44 42 76 ; 2 4 5 10 1 2 71 31 4 14 165 20 • • • i*n doci Oeublfcil Mmef Mir, F .w 17 100 44 18 16 64 38 28 27 12 4 nil 31 7 14 174 26

• • 14 ei F a i r Pfoboblo F«w 18 100 66 4 ) 14' 16 10 5 2 1 * 27 NP 11 175 25 3 4 . S t c 2 • *• • 161) R tbu i l t S o v . r * Savara S a v . r t 34 100 I t 66 1) 12 2 0 211 26 NP 26 151 31 Pdvamani daarrevad a * a raauir of oumpina.

• * • 1624 • - - - 4 « . 100 41 I S 66 16 14 6 1 21) 21 NP 1) I S ) 34 t* m a . . • • • • 17.4) • - • 3 4 100 44 16 4 4 67 21 20 12 3 210 27 N P 16 16) 27

- • - - i ' -1746 1746 - — . — 1

S I )2

loo 47 45 14 100

67 4 }

60 64

22 16

20 4

10 2

3 0

2 74 274

21 31

N P 6

20 28

166 ISO

16 28

' ; appro»n»taraW 6 ' thick

- -.—!-n w I M S No No No

33 41

46 46 !•«

45 44

45 41

4 ) 4 )

40 40

87 67

80 60

34 57

7 20

6 16

3 7

2 2

274 275

NP 24

NP 20 15

154 2 14

2 6 22

At fhit locat ion Hii» mofaf io l ondarWin^ tha lavar of so i l m d n a r a d bv tawpla 31 ,

— 18 66 IA.66

• - • 354114 -iffo 11 46 . I f 45 41 75 28 27 I S ? 260 35 II 17 164 26 Sample ol 1 ' leyar imiwadioUtY tfwdar pavomawt. probafcty fill to ^raplaca _ O¥arco>

• • • 140) 14 06

Poor Ot f in i t . *« i ' -Ha } ' Ma i l "

S«v«ra 3 5 4 I I 3

35 36

100 100

48 44

46 48

44 46

11 100 67 42

70 76 76

31 52 54

I S )e 36

14 27 ) l

6 11 20

2 4 12

261 21) 216

28 26 35

NP 4 1)

23 16 21

1.64 116 166

30 21 SI

Sample of nativk M i l under the material shown i m M e d i a t e h r above

• 1141 21 62 Poor

No Indofi.tlo

No M a . i "

No 3 . . . r a

4 t « 354203 100

100 44

16 48

84 4 )

64 86

) l 40

10 15

9 14

3 12

1 11

244 274

HP )2

Nt NP

14 IS

l« 5 164

16 20 Thift lever 2 * thick . domo when ftampled

• * U ( 2 - 154204 IOO 44 44 62 70 34 28 10 6 27) 14 0 16 177 17

M ISC CLLA N C O l >TE s

New JefMy Route

Veor U<d

Concrcta niicfeiitM

, Joint Tvpe

S w b b a . . Thicl in. t f t

Locotion R a v e m e n t C o r w l i i i o n Sam,la S i . v . A n a l v a i o - % Paft . inq Hytfrn Anal<>l>ZSwllar ^ A L L PI Shrinhaac r u o Avara^a, Total Daity Truck TralTc, % C o m m e n t s

New JefMy Route

Veor U<d

Concrcta niicfeiitM

, Joint Tvpe

S w b b a . . Thicl in. t f t

Locotion G c n t r a l Amipinq Faulting C r a c k t N* »• l l f r \' • 4 •10 •40 •60 »fOO 001 mm

L L PI Witio

Avara^a, Total Daity Truck TralTc, % C o m m e n t s

6 6

142) 141)

.9" 8 '

i-u't t K . l l . n l Fair

No Indofinit.

Na ! l ' "

No Vapf Few

)S4I I0 45 41 • 2 75 64 57 41 » 27 16 15 7 1 211 22 3 I ) 161 17 556 S u b b a w ftompie immediorelv u n d e r povemant

i"? 25

l i l t 14)6

r o-

Ha iM^tt Joint 1164 34)

V m h o r &.vtr. la

Scvora Savara 364 III )S4 >SI

I t 42 01 02 100

76 44

67 66

46 60

36 52

20 42

16 34

4 20

1 8

2.75 210

11 21

HP 2

1) II

160 • 41

17

14

550 \W

25 26

14)6 14)2

V 4"

424

• 1 "

i^or

V . n ( ^ r

Otftnit. No

S*Mr.

F m u a n t

S«v«r«

S64 3S> U4 254 >S4 IS4

100 100

44 14

47

44

45 47

ISO

80

12 13

74 85 10

67 4 ) S i

6 3 38 45

? 1 14 14

21 13 10

216 210 214

46 46 22

20 14 0

24 22 14

140 166 176

24 34 18

to^fr 2016 2341

2 6 14)2 4" N. )<>U.x iil Good toilbtfal 1'*̂ No ) « i 1)5 100 11 t) 61 26 4 3 2 1 2 1 ) NP NP 2 M I Samplf from imwed lataly under poyamawl

k Truck traffic on pavamanra tabularcd it opproffimofely i the ^etal »howa

1959 ) 7. M>"