S.T.A.R., INC.

S.T.A.R., INC.

SEALCOATING ADDITIVES

DEFINITIONS

ADDTIVES:

THING ADDED

SEALCOATING ADDITIVES:

THINGS (CHEMICALS) ADDED TO

ACCOMPLISH SPECIFIC OBJECTIVES

OBJECTIVES

THICKENING:

To accommodate large amounts of water.

FAST DRYING:

Even under not-so-ideal weather conditions.

UNIFORM DRY COLOR:

Under shade or shine.

SAND OR AGGREGATE SUSPENSION:

No streaking.

IMPROVED PROPERTIES:

Flexibility and elongation

Toughness

Water resistance

Resistance to chemicals, de-icing salts, oils, fats, grease etc..

SEALCOATING ADDITIVES

Have been used for the last 20-25 years

Extensively used since mid-70’s when FAA ADOPTED ACRYLONITRILE/BUTADIENE LATICES FOR RUBBERIZING COAL TAR BASED SEALER.

Prior years, rubber was blended directly in asphalt or tar for modification.

TYPES OF ADDITIVESAND

SPECIFIC PURPOSES

1. ADDITIVES THAT DO NOT MODIFY INGREDIENTS.

THICKENERS: Viscosity building additives

A. SALTS, MILD ACIDS e.g. MgC12, Acetic Acid Cost

Effective but introduce WATER-SENSITIVITY.

B. NATURAL GUMS e.g. Xanthum Gum, Expensive, Introduce PERMANENT WATER-SENSITIVITY.

C. BENTONITIC CLAYS Cost effective, some water sensitivity in film, which can be counterbalanced.

D, SPECIALITY POLYMERS Very cost-effective. Do not introduce water sensitivity.

2. ADDITIVES THAT MODIFY INGREDIENTS

A. CLAY PROPERTIES MODIFIERS

Additives are available that modify the surface characteristics of the clays in the sealer

Drastic reduction in water sensitivity of cured films of sealer.

B. ADDITIVES THAT MODIFY THE PROPERTIES OF THE BINDER-ASPHALT AND TAR.

REDUCE TEMPERATURE SUSCEPTIBILITY;Tack and flow in summer and hardening and brittleness in winter months.

INCREASE TOUGHNESS;Greater resistance to abrasion, scour and wear. Better retention of aggregates.

INCREASE FLEXIBILITY AND ADHESION;Better anchoring of aggregates.

REDUCE BLEEDING OF THE BITUMEN;Asphalt and tar to the surface of the coating.

OTHER BENEFITS

THICKENING: due to pH alteration of the coating system.

FAST DRYING: even under not-so-ideal weather conditions.

UNIFORM DRIED COLOR OF THE SEALER.

POLYMERIC ADDITIVES

RUBBER EMULSIONS are dispersion of giant polymeric molecules in water.

These molecules have large chain length and are heavily branched:

Dispersed in sealcoating materials, they spread and form a flexible and tough NETWORK OF POLYMERS.

AS THE SEALCOATING DRIES;

The water is expelled out of the film at a rather uniform rate as the polymer chains spread and tighten throughout the film, this;

Reinforcing the properties of the sealcoating,

Reducing the drying time and

Producing uniform dark color. The bitumens; asphalt and tar coalesce at a uniform rate.

FLEXIBILITY AND TOUGHNESS ARE ENHANCED.

ADDITIONALLY

Polymer segments FUSE WITH THE BITUMENS, ASPHALT AND TAR in the sealer at the points of surface contacts, thereby modifying its properties.

HARDNESS

FLEXIBILITY

TEMPERATURE SUSCEPTIBILITY

CHEMICAL RESISTANCE

ADHESION.

POLYMER NETWORK

TAR PARTICLES

CLAY PARTICLES

OVERALL CONTRIBUTION

FASTER DRYING, UNIFORM COLOR ON DRYING

TOUGHNESS AND FLEXIBILITY

BETTER AGGREGATE SUSPENSION,

IMPORVED RESISTANCE TO CHEMICALS

LET US EXAMINE A FEW COMMONLY USED POLYMERS FOR ADDITIVES

WE WILL REVIEW THE GENERAL PROPERTIES OF THE FOLLOWING RUBBERS OR POLYMERS FOR THEIR RESISTANCE TO COMMONLY ENCOUNTERED CHEMICALS AND WEATHER RELATED ELEMENTS.

PVA - POLYVINYLACETATE/ACRYLIC COPOLYMER

SBR - STYRENE BUTADIENE COPOLYMER

NR - NATURAL RUBBER

BR - BUTADIENE RUBBER

CHLOROPRENE - NEOPRENE

NBR - ACRYLONITRILE/BUTADIENE RUBBER

IF THE POLYMER HAS CERTAIN DEGREE OF WEAKNESS

THE ADDITIVE BASED ON IT WILL ADVERSELY AFFECT THE PROPERTIES OF THE CURED SEALCOATING

FOR EXAMPLE

IF THE POLYMER OR RUBBER IS:

1. POOR RESISTANCE TO WATER - THE CURED FILM OF THE SEALER WILL BECOME SOFT

UNDER WATER AND WILL BE EASILY TORN BY THE TRAFFIC,

2. POOR RESISTANCE TO FUEL, GAS, OIL ETC.: THE SEALCOATING WILL LOSE EVEN ITS ORIGINAL RESISTANCE PROPERTIES.

IT WILL BECOME A WEAK LINK IN THE SEALCOATING

THE MANUFACTURER WILL ASSIST IN THE SELECTION OF THE PROPER ADDITIVE.

CHEMICAL RESISTANCE PROPERTIES

POLYMER TYPE - POLYVINYLACETATE/ACRYLIC CO-POLYMER (PVA)

RESISTANCE TO - MILD HYDROCARBON SOLVENTS AND SOME RESISTANCE TO WEAK ACIDS AND ALKALIS.

RESISTANCE TO SPECIFIC CHEMICALS - That attack asphalt pavement.

Materials Rating

Water POOR

Hydraulic Oils (Petroleum) POOR

Kerosene POOR

Lactic Acid FAIR-GOOD

Fat FAIR-GOOD

Vegetable Oils FAIR-GOOD

Lubricating Oils FAIR-GOOD

Transmission Fluid (Type A) FAIR-GOOD

Turbine Oil FAIR-GOOD

Turpentine EXCELLENT

Isopropanol VERY POOR

ATTACKED BY: WATER, ULTRAVIOLET RADIATION, ALKALIS, ACIDS, ALCOHOLS, AROMATIC HYDROCARBONS, GLYCOLS ETC.

CHEMICAL RESISTANCE

POLYMER TYPE - ACRYLONITRILE BUTADIENE (NBR)

RESISTANT TO - MANY HYDROCARBONS, OILS, FATS, GREASE, HYDRAULIC FLUIDS,CHEMICALS ETC.

ATTACKED BY - OZONE, KETONES, CHLORINATED AND NITRO HYDROCARBON

SOLVENTS.

RESISTANCE TO SPECIFIC CHEMICALS - That attack asphalt pavements.

Materials Rating

Water A

Hydraulic Oils (Petroleum) A

Kerosene A

Lactic Acid A

Fat A

Vegetable Oils A

Lubricating oils A

Transmission Fluid (TYPE A) A

Turbine Oil B

Turpentine A

Isopropanol B

A-Recommended, little or no effect

B-Minor to moderate effect

C-Moderate to severe effect - not recommended

U-Poor-not recommend.


POLYMER TYPE - STYRENE/BUTADIENE (SBR)

NATURAL RUBBER (NR)

BUTYL RUBBER (BR)

PROPERTIES OF ALL ABOVE TYPES ARE SIMILAR.

RESISTANCE TO - MODERATE CHEMICALS, ORGANIC ACIDS, ALCOHOLS, KETONES, ALDEHYDES


Materials Rating

Water EXCELLENT

Hydraulic Oils (Petroleum) VERY POOR

Kerosene VERY POOR

Lactic Acid EXCELLENT

Fat VERY POOR

Vegetable Oils VERY POOR

Lubricating Oils VERY POOR

Transmission Fluid (Type A) VERY POOR

Turbine Oil VERY POOR

Turpentine VERY POOR

Isopropanol VERY POOR

ATTACKED BY: OZONE, STRONG ACIDS, OILS, GREASE, MOST HYDROCARBONS SOLVENTS.


POLYMER TYPE - CHLOROPRENE POLYMER (NEOPRENE)

RESISTANCE TO - MODERATE CHEMICALS, MILD ACIDS, OILS, FATS, GREASE AND SOME SOLVENTS.


Materials Rating

Water EXCELLENT

Hydraulic Oils (Petroleum) FAIR-GOOD

Kerosene POOR


Fat FAIR-GOOD

Vegetable Oils FAIR-GOOD

Lubricating Oils FAIR-GOOD

Transmission Fluid (Type A) FAIR-GOOD


Turpentine VERY POOR

Isopropanol EXCELLENT

ATTACKED BY: ESTERS, KETONES, CHLORINATED AND NIRTO-HYDROCARBON SOLVENTS, STRONG OXIDIZING ACIDS.


POLYMER TYPE - ACRYLONITRILE BUTADIENE (NBR)

RESISTANCE TO - MANY HYDROCARBONS, OILS, FATS, GREASE, HYDRAULIC FLUIDS, CHEMICALS ETC.


Materials Rating

Water EXCELLENT

Hydraulic Oils (Petroleum) EXCELLENT

Kerosene EXCELLENT


Fat EXCELLENT

Vegetable Oils EXCELLENT

Lubricating Oils EXCELLENT

Transmission Fluid (Type A) EXCELLENT


Turpentine EXCELLENT

Isopropanol FAIR-GOOD

ATTACKED BY: OZONE, KETONES, CHLORINATED AND NIRTO-HYDROCARBON SOLVENTS.

CONCLUSIONS

1. ACRYLONITRILE/BUTADIENE BASED POLYMERS HAVE TH BEST OVERALL PROPERTIES. THEY REINFORCE AND BOOST THE PROPERTIES OF ASPHALT AND REFINED COAL TAR BASED SEALERS.

THEY HAVE BETTER RESISTANCE TO OILS AND OTHER PETROCHEMICALS THEN STYRENE/BUTADIENE RUBBERS. REST OF THE PROPERTIES ARE SIMILAR.

APPROVED BY FAA P-625, ENGINEERING BRIEFNO. 46

2. PVA-POLYVINYLACETATE/ACRYLIC COPOLYMERS ARE NOT RECOMMENED. THEY INTRODUCE WEAK SPOTS IN THE CURED FILM THAT IS ATTACKED BY WATER AND ALKALI.

THESE CONCLUSIONS ARE BASED ON POLYMER PROPERTIES. THE MANUFACTURER OF ADDITVE MAY HAVE OVERCOME SHORTCOMINGS BY POLYMER MODIFICATION WHICH HE MUST ESTABLISH.

Majority of the POLYMERIC ADDITIVES:

º Produce Thickening,º Speed up Drying Time,º Produce Uniform Dry Color,º Help to Suspend Aggregates.

But they differ in their abilities to;

º Reinforce the properties like, Flexibility, Toughness, Temperature

Susceptibility etc.

º Improve resistance to Chemicals, oils, fats, grease, de-icing salts, aromatic fuels etc.

LET US EXAMINE A FEW COMMONLY USED POLYMERIC ADDTIVES.

CHEMICAL RESISTANCEPOLYMER TYPE - POLYVINYL ACETATE/ACRYLIC CO-

POLYMER, (PVA)

RESISTANT TO - MILD HYDROCARBONS SOLVENTS AND WEAK ACIDS. SOME RESISTANCE TO WEAK ALKALIS.

ATTACKED BY - WATER, ALKALIS, ULTRAVIOLET RADIATION, ACIDS, ALCOHOLS, AROMATIC HYDROCARBONS, GLYCOLS ETC.


Materials Rating

Water C

Hydraulic Oils (Petroleum) C

Kerosene C

Lactic Acid B

Fat B

Vegetable Oils B

Lubricating oils B

Transmission Fluid (TYPE A) B

Turbine Oil B

Turpentine A

Isopropanol U

Sodium Hydroxide (10%) C





CHEMICAL RESISTANCEPOLYMER TYPE - 1. STYRENE BUTADIENE (SBR)

2. NATURAL RUBBER (NB)

3. BUTYL RUBBER (BR)

Properties of all the types similar.

RESISTANT TO - MODERATE CHEMICALS, WET OR DRY. ORGANIC ACIDS, ALCOHOLS, KETONES, ALDEHYDES.

ATTACKED BY - OZONE, STRONG ACIDS, OILS, GREASE, MOST HYDROCARBONS.


Materials Rating

Water A

Hydraulic Oils (Petroleum) U

Kerosene U

Lactic Acid A

Fat U

Vegetable Oils U

Lubricating oils U

Transmission Fluid (TYPE A) U

Turbine Oil U

Turpentine U

Isopropanol U

Sodium Hydroxide (10%) B





CHEMICAL RESISTANCE

POLYMER TYPE - CHLOROPRENE POLYMER (NEOPRENE)

RESISTANT TO - MODERATE CHEMICALS, MILD ACIDS,OILS, OZONE, FATS, GREASE AND SOME SOLVENTS.

ATTACKED BY - ESTERS, KETONES, CHLORINATED AND NITRO HYDROCARBON SOLVENTS, STRONG OXIDISING ACIDS.


Materials Rating

Water A

Hydraulic Oils (Petroleum) B

Kerosene C

Lactic Acid A

Fat C

Vegetable Oils B

Lubricating oils B

Transmission Fluid (TYPE A) B

Turbine Oil B

Turpentine U

Isopropanol A





CONCLUSIONS

1. Acrylonitrile/Butadiene polymers (NBR TYPE) have the best overall properties. They reinforce and boost the properties of asphalt and coal-tar based sealers.

2. Acrylonitrile/Butadiene polymers have better resistance to oils and other petrochemicals then Styrene/Butadiene polymers. Rest of the properties are similar.

3. Polyvinyl Acetate/acrylic co-polymers (PVAs) are not recommended due to poor water and alkali resistance. Introduce weak spots in the film when attacked by water. Useful only as thickeners and for speeding up drying.

TYPICAL MIX DESIGNS

1. FINISH COAT MIX

Components Gals. Solid Gals.Tar-31.34 (B)

Sealer 100 40.83

Clay- 8.95 (F)

Water 40 -

A/B Latex 3 1.22 (B)

TOTAL 143 42.03

Solids, % By Volume 29.40

Sealer, % By Volume in the total mix 70.00

Binder = 31.34 + 1.22 = 32.56 = 3.64

Filler 8.95 8.95 1

Application rate =00.11 Gal. Total Mix/Sq.. Yd.

=82.00 Sq.. Feet/Gallon

Wet Film Thickness =19.50 Mils.

Dry Film Thickness = 5.80 Mils.

TYPICAL MIX DESIGNS

1. FILLER COAT MIXComponents Gals. Solid Gals.

Tar-31.34 (B)

Sealer 100 40.83

Clay- 8.95 (F)

Water 50 -

A/B Latex 4 1.63 (B)

Sand/Aggregate 22.6 (500#) 22.60 (F)

TOTAL 176.60 65.06

Solids, % By Volume 36.84

Sealer, % By Volume in the total mix 56.50

Binder = 31.34 + 1.63 = 32.97 = 1.05

Filler 8.95 +22.60 31.55 1.00

Application rate =00.21 Gal. Total Mix/Sq.. Yd.

=43.00 Sq.. Feet/Gallon

Wet Film Thickness = 37.30 Mils.

Dry Film Thickness = 13.80 Mils.

TOTAL FILM THICKNESS (1 +2), Wet - 56.8 Mils

Dry - 19.60 Mils

FAA P-625(Engineering Brief No. 46, Issued 1/1/91)

COMPOSITION OF MIXTURE(Quantities per gallon of emulsion)

Type of Water Aggregate Rubber Application

Sealcoat Gal./Gal. Lbs./Gal. Gal./Gal. Rate

Gal. Sq.. Yd.

Rubberized Sand Slurry 0.8 (Max.) 4-20 0.04-0.18 0.2-0.55

Rubberized Emulsion 0.8 (Max.) - 0.03-0.05 0.10-0.20

Sand Slurry 0.15 (Max.) 2-5 - 0.15-0.20

Plain Emulsion 0.10 (Max.) - - 0.08-0.10

FAA P-625 Formulations

Engineering Brief No. 46

RUBBERIZED SAND SLURRY

Low End

Components gals. Solid gals.

SEALER 100 40.83

WATER 50 -

A/B Latex 4 1.63

Sand/Aggregate 18 (400#) 18

TOTAL 172.00 60.46

Solids, % By. Vol.. 35.30 %Sealer by Vol.. In mix 58.10 (BINDER/FILLER) Ratio 1.22/1

Application rate (Gal/Sq.. Yd.) 0.20 Wet Film Thickness, Mils. 35.64 Dry Film Thickness, Mils. 12.58

Dry Film Thickness, 2 Coats 25.16

Dry Film Thickness, 3 Coats, (2 X A + B) 30.39

High End


SEALER 100 40.83

WATER 80 -

A/B Latex 18 8.15

Sand/Aggregate 90 (2000#) 90

TOTAL 288.00 138.98

Solids, % By. Vol.. 48.26 % Sealer by Vol.. In mix 34.72 (BINDER/FILLER) Ratio 0.40/1

Application rate (Gal/Sq.. Yd.) 0.50 Wet Film Thickness, Mils. 89 Dry Film Thickness, Mils. 43.30

Dry Film Thickness, 2 Coats 86.60

Dry Film Thickness, 3 Coats, (2 X A + B) 94.85

FAA P-625 Formulations

Engineering Brief No. 46

RUBBERIZED EMULSION

Low End


SEALER 100 40.83

WATER 40 -

A/B Latex 3 1.22

TOTAL 143.00 42.03


Application rate (Gal/Sq.. Yd.) 0.10

Wet Film Thickness, Mils. 17.82 Dry Film Thickness, Mils. 5.23

High End


SEALER 100 40.83

WATER 80 -

A/B Latex 5 2.03

TOTAL 185.00 42.86


Application rate (Gal/Sq.. Yd.) 0.20 Wet Film Thickness, Mils. 35.64 Dry Film Thickness, Mils. 8.25

FAA P-625ENGINEERING BRIEF NO. 46

(NON-RUBBERIZED SYSTEMS)

SAND SLURRY PLAIN EMULSION

COMPOSITION GALS. SOLID COMPOSITION GALS. SOLID

GALS. GALS.

SEALER 100 40.83 SEALER 100 40.83

WATER 15 - WATER 10 -

SAND 22.6 22.6

(500#)

TOTAL 137.60 63.43 TOTAL 110.00 40.83

SOLIDS, % BY VOL. 46.10 SOLIDS, % BY VOL. 37.10

SEALER, % BY VOL. 72.70 SEALER, % BY VOL. 90.90

BINDER/FILLER RATIO-1/1 BINDER/FILLER RATIO-3.5/1

APPLICATION RATE 0.175 APPLICATION RATE 0.09

(GAL/SQ.YD.) (GAL/DQ.YD.)

WET FILM THICKNESS 31.2 WET FILM THICKNESS 16.0

(IN MILS.) (IN MILS.)

DRY FILM THICKNESS 14.38 DRY FILM THICKNESS 5.95

(IN MILS.) (IN MILS.

DRY FILM THICKNESS OF 3 COATS SYSTEM, 34.71 (2 FILLER + 1 FINISH COAT

PERFORMANCE-WHAT TO EXPECT

The quantities of the components in the mix design must be well balanced to yield the proper:

BINDER/FILLER RATIO

DRIED FILM THICKNESS

WATER - Excessive amounts:

REDUCE SOLIDS BY VOLUME,

YIELD THINNER DRY FILMS

SAND/AGGREGATES

As a general rule, increasing amounts DETRACT PERFORMANCE;

REDUCE FLEXIBILITY. Coating becomes increasingly tougher and FAILS TO FLEX

WITH THE PAVEMENT.

REDUCE ADHESION. Excessive absorption of the binder. Also increased toughness overcomes the adhesive forces.

REDUCE WEATHERING AND CHEMICAL RESISTANCE. Due to increased porosity.

Do not increase the skid resistance. Levels off at 7-8 lbs. Per gallon.

ADDITIVES

Right Additive used in right proportion will;

Reinforce the properties,

Improve the overall performance

BUT CAN NOT

OVERCOME DEFICIENCIES of thinner films, caused by excessive water,

Supply enough binder to satisfy the demand of the excessive amounts of aggregates used in the mix.

PERFORMANCE

A - POSITIVE EFFECTS REACH A MAXIMUM. ADDITIONAL AGGREATES DO NOT IMPROVE PERFORMANCE.

B - POSITIVE PROPERTIES DECREASE WITH INCREASE IN AGGREGATE CONTENT.

B’- POLYMERIC ADDITIVES IMPROVE THE PERFORMANCE, AT A GIVEN AGGREGATE LOADING. THE TREND IS STILL

THE SAME.

ABRASION & SKID RESISTANCE

MAXIMUM ACCEPTANCEPERFORMANCE

B

B’ (POLYMER ADDED)

FUEL RESISTANCE ADHESION &FLEXIBILITY

INCREASING AGGREGATE LOADING -----------

RECOMMENDATIONS

1. WATER, per 100 gallons of the sealer;

FILLER COAT - 50 GALLONS.

FINISH COAT - 40 GALLONS.

2, AGGREGATES, per gallon of the sealer;

FILLER COAT - 4-5 LBS.

IF USED IN BOTH COATS - 2-2.5 LBS.

BINDER/FILLER RATIO, BY VOL. - 1/1

3. ADDITIVE, As specified. Follow Manufacturer’s Recommendations.

MIX DESIGNSSealcoatings are seldom applied as a concentrate. The most common practice is to add the following in recommended quantities, called MIX DESIGN.

1. WATER is added to;

reduce viscosity, impart fluidity for ease in application,

satisfy the water demand of the sand/aggregates.

SHALL BE;

CLEAN, POTABLE

FREE FORM HARMFUL SOLUBLE SALTS,

at min. 50 DEG. F. (10 DEG. C)

at pH TO CONFORM SEALCOATING MANUFACTURES RECOMMENDATION.

2. AGGREGATES are added to;

improve SKID RESISTANCE,improve ABRASION RESISTANCEcover MINOR SURFACE DEFECTSimpart an UNIFORM APPEARANCE.

SHALL BE;

NATURAL OR SYNTHETIC,ANGULAR FOR PROPER INTERLOCKING OF PARTICLES,CLEAN, HARD, DURABLE UNCOATED,FREE FROM LUMPS OF CLAY AND ALL ORGANIC MATTER,AVG. GRAIN FINENESS 60-70 MESH, DISTRIBUTION BETWEEN 20-30 MESH TO 100 MESH.

3. POLYMERIC ADDITIVE - AS SPECIFIED,

FAA P-625 SPECIFIESACRYLONITRILE (30-49 PARTS)/ BUTADIENE (51-70 PARTS), MIN. SOLIDS, % BY WT. - 40.00

4. SEALCOATING MATERIAL

COAL TAR PITCH EMULSION TO MEET RP-355e except WATER SHALL NOT EXCEED 50% BY WT.

FAA P-625, ENGINEERING BRIEF NO. 46 IS A GUIDE SPECIFICATION.

REQUIREMENTS-MUST PASS A SERIES OF TEST.

TEST APPLICATION-250 SQ. YARDS AND WATCH FOR PERFORMANCE.

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