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7/27/2019 effect of sand grading on characteristics of mortar

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Chapter1

INTRODUCTION

1.1General:-Sand constitutes bulk of the mortar volume. Composition of sand and its grading can

influence the characteristics of mortars in fresh as well as in hardened state. Sand plays an

important role for the preparation of mortar.

Sand is a naturally occurring granular material composed of finely divided rock and

mineral particles. The composition of sand is highly variable, depending on the local rock

sources and conditions, but the most common constituent of sand in inland continental settings

and non-tropical coastal settings is silica (silicon dioxide, or SiO2), usually in the form ofquartz.

Sand to be used should be natural sand or crushed sand or river sand. It should be well

graded, dry, hard, durable, clean and free from clay, dirt, organic matter and adherent coating. It

should not contain harmful impurities such as iron, pyrites, alkalies, salts, coal, mica, shale or

other mineral in such a form or in such quantity as to affect the hardening, strength and durability

of the mortar.

Mortar is a mixture of a binding material, sand and water and is different from concrete

which contains large-sized coarse aggregate also.

For the mortar to be workable and strong the ratio of cement to sand should normally be 1:3 to

1:6 by weight. (9)

We are using sand for the preparation of mortar and concrete. Cement mortar consists of

cement as binding material, sand in different proportions and water. The use of much weaker

cement mortar i.e. mortars of low cement content, is not satisfactory since any notable reduction

in cement content leads to reduction in workability and less cohesion. Mortar is used for the

construction of walls and for plastering, etc.
http://en.wikipedia.org/wiki/Granular_materialhttp://en.wikipedia.org/wiki/Rock_(geology)http://en.wikipedia.org/wiki/Mineralhttp://en.wikipedia.org/wiki/Silicahttp://en.wikipedia.org/wiki/Siliconhttp://en.wikipedia.org/wiki/Quartzhttp://en.wikipedia.org/wiki/Quartzhttp://en.wikipedia.org/wiki/Siliconhttp://en.wikipedia.org/wiki/Silicahttp://en.wikipedia.org/wiki/Mineralhttp://en.wikipedia.org/wiki/Rock_(geology)http://en.wikipedia.org/wiki/Granular_material


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Depending upon the type of binder, mortar can be classified as below:-

1. cement mortar2. lime mortar3. lime-cement mortar4. special mortars

Cement mortar is the strongest type of mortar and is therefore preferred for the use in the

construction of structures subjected to heavy load. Cement mortar is prepared by mixing sand

and cement in a dry condition uniformly and then adding the required quantity of water in a

central depression of sand-cement mass and mixing thoroughly with showels and spades.

Mortar is prepared from a cementing materials, sand and water, with the sand accounting

for most of the volume of the mixture.

Mortar using fine sand results in lower tensile bond strength. The mortars with coarser

sand give better bond strength than with finer sand. The mortar with coarser sand gives better

compressive strength. (5)

The most important function of sand in mortar is to assist in producing workability and

uniformity in the mixture. It also helps in cement paste to hold the coarse aggregate particles in

suspension, thus promoting plasticity and preventing the possibility of segregation of mortar.

(10)

Sand is an inert occurring material of size less than 4.75mm. It is used as a material of

construction not only as filling and as a porous foundation blanket (as for roads) but also to a

wide extent as a filtering medium and as constituent of mortars and concrete. In view of this

important applications sand is described as naturally granular material of a certain grain size

irrespective of the shape of the grains, thus, uniformity and their mineral composition.

Depending on the nature of rock from which it was found and on the erosive action to

which it has been subjected many other minerals may be found as constituents- mica, feldspar

shales are also found. The presence of feldspars, an unstable mineral causes development of hair

cracks.


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1.1.1Classification of sand and sand grading:-Sand is classified according to the sources such as river sand, pit sand and sea sand. Sand

is also classified according to its fineness as below: Fine Sand : FM : 2.22.6 Medium Sand : FM : 2.62.9 Coarse Sand : FM : 2.93.2

The most important quality of the sand is its gradation that is to say its particle size

distribution as determined by sieve analysis. The grading of an sand coarse to fine has a marked

effect on the workability, uniformity and finishing qualities of mortar.

A well graded, uniformly distributed sand produces a dense hard and compact mortar and a

poorly graded sand produces a harsh mortar having more voids and less density and of course

less strength. Good grading implies that a sample of sands contains all standard fractions of sand

in required proportions such that the sample contains minimum voids.

A sample of the well graded sand containing minimum voids will require minimum paste

to fill up the voids in the sand. Minimum paste will mean less quantity of cement and less

quantity of water, which will further mean increased economy, higher strength, lower-shrinkage

and greater durability. Grading for maximum density gives the highest strength, and that the

grading curve of the best mixture resembles like a parabola. Mortar made from sand grading

having least surface area will require least water which will consequently be the strongest.

1.1.2Mortar Properties:-

The different properties of mortar are compressive strength, water retentivity, workability,

drying shrinkage, water absorption and freezing-and-thawing resistance. Some properties of

mortar, it has been are influenced greatly by the type of sand used. The particle-size grading of

the sand, or the distribution of grain sizes in it, has been reported to have an important influence

on certain mortar properties including the strength, water retention and workability. These

properties are then measured to determine the influence of sand grading on the properties of

mortar

.


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1.2 Necessity:-

Mortar is very important part of any construction with strength and beauty point of view.Mortar is used in masonry, decorative and protective plasters and in the production of small-

sized element such as bricks, mortar blocks, etc. Cement mortar are extensively used in masonry,

in damp-proof courses and for plastering and pointing.

There are limited studies on the influence of sand grading on the characteristics of mortar.

So in this paper we tested the different properties of mortar like compressive strength, water

absorption which are influenced by sand grading.

1.3 Objective:-

Some properties of mortar are influenced greatly by the type of sand used. So the prime

purpose of this project is to study the effect of sand grading on different properties of mortar

such as compressive strength, water absorption and workability.

1.4 Summary:-

In this chapter we have studied about grading of sand, properties of mortar, necessity and

objective of the project. In the next chapter we shall discuss about the work carried by different

investigators.


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Chapter 2Literature review

2.1 Introduction:-

This chapter deals about the brief description about the authors who did research on the

Influence of sand grading on the characteristics of mortars and presented paper on it. This

chapter contains the brief description about the paper ofB.V. Venkatarama Reddy and Ajay

Guptawho gave detailed information of the Influence of sand grading on the characteristics of

mortar andE. Rivetand T. Ritchiewho presented a paper about the influence of sand grading

on mortar properties. FurtherJiong Hu and Kejin Wangpresented a paper on Effects of

Aggregate on Flow Properties of Mortar and G. De SchutterandA. M. Poppe examined and

presented their research on Quantification of the water demand of sand in mortar.Kolias

carried out research on The influence of size and hardness of sand particles and their

proportions on the friction characteristics of cement mortars. A research carried out by Suresh

Thokchom et.al. on Effect of water absorption, porosity and sorptivity on durability of

geopolymer mortars.Prashant Agrawal et.al.presented their research on Effect of fineness of

sand on the cost and properties of mortar

2.2 Literature Review:-

E. Rivetand T. Ritchiepresented his research on the influence of sand grading on mortar

properties. Accoding to them some properties of mortar like strength, water retention, and

workability, compressive strength, water retentivity, water absorption and freezing-and-thawing

resistance are influenced greatly by the type of sand used. The particle-size grading of the sand,

or the distribution of grain sizes in it, has been reported to have an important influence on certain

mortar properties. In addition, the ability of mortar to bond to bricks has been related to the


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particle-size grading of the sand. They used five sands to determine the influence of sand grading

on mortar. A preliminary study has been made to obtain information on the influence of sand

grading on mortar properties. In this study, masonry mortars were prepared from sands which

differed in grading. The same cementing material, a masonry cement of the portland cement -

interground limestoneair entraining agent type, was used in preparing the mixes.

Through their study they concluded that the change in proportion of cement to sand caused

a considerable change in compressive strength of mortar. The bulk density of the mortars was

influenced by the grading of the sand, and also the water absorption properties of the mortars.

The water retention property of the mortars appeared to be independent of the sand grading, but

varied considerably when the proportion of cement to sand was changed. (1)

Koliascarried out research on The influence of size and hardness of sand particles andtheir proportions on the friction characteristics of cement mortars. Two types of investigations

were performed. The first consisted of mixes with constant grading of sand, either limestone or

emery, in which one fraction was replaced by the same fraction of the other type of sand. The

second consisted of mixes of limestone sand in which a certain amount of emery sand, each one

of four different fractions, was added each time. The exact amount of emery sand added was

calculated for each fraction so that in each series of tests the total surface area of emery sand was

constant, regardless of the fraction used.

It was found that the finer fractions are more effective in influencing the skid resistance

value (SRV) of mortars. The second investigation confirmed that the total surface area of hard

particles determines the friction characteristics of the mortars. It seems, however, that an

optimum total surface of hard particles exists, and further increase of which does not cause

additional increase of the SRV. (2)

G. De Schutter

and A. M. Poppe carried out research on Quantification of the water

demand of sand in mortar according to them, the sand type has an important influence on the

properties of mortar. Two series of mortar tests have been undertaken. A first series with a

standard mortar composition, and a second series with a modified composition (by changing the

sand cement factor) in order to obtain a certain target value for the workability.


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The results show a very significant influence of the sand type on the mortar properties

with important consequences regarding mix design. The water demand related with the different

sand types is investigated considering some geometric sand properties like fineness modulus

relative specific surface and fictitious weight. The sand type has a significant influence on the

rheological and mechanical properties of mortar, and thus on the mix design of the mortar. A

good correlation exists between the water demand and the apparent dry density of the sand. (3)

Jiong Hu andKejin Wangpresented a paper on Effects of Aggregate on Flow Properties

of Mortar. According to them the effects of aggregate characteristics on flow ability of mortar

mixtures were investigated. Two types, five single sizes, and three gradations of fine aggregate

were considered. Uncompacted voids of the aggregates were measured.

The results concluded by them indicated that w/c, uncompacted voids, size, and volume of

aggregate have a great impact on mortar flow ability. Generally, aggregate having higher

uncompacted void content provides mortar with a lower flow. In addition to w/c, uncompacted

voids, size, and volume of aggregate are also significantly influence mortar flow ability. For

mortar with a low s/c, the effect of aggregate size on the mortar flow ability may not be

significant, but the effect will become significant as s/c increases. (4)

B.V. Venkatarama ReddyandAjay Gupta from Department of Civil Engineering, Indian

Institute of Science, Bangalore has presented paper on Influence of sand grading on the

characteristics of mortars. Influence of sand grading on the characteristics of two types of

mortars was examined in this paper. Three different sand grading were used to examine the

workability, strength, water retentivity, drying shrinkage and stressstrain characteristics of

cement mortar and cementlime mortar. Bond strength, compressive strength and stressstrain

characteristics of soilcement block masonry were also examined using these mortars. They also

studied the effect of sand characteristics (fineness modulus, void ratio, specific surface, etc.) and

water content of the mix on the mortar strength.

They examined some properties of fresh mortar and observed that for a given consistencymortars with very fine sand required 25-30% more water than similar mortars having normal

sand grading. They also observed that for a given consistency the compressive strength of mortar

decreases with increase in fineness of sand. Water retentivity of cement mortar increases with

increase in fineness of sand. Sand grading greatly affects the drying shrinkage values of both the

mortars. (5)


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Suresh Thokchomet.al. did research on Effect of water absorption, porosity and sorptivity

on durability of geopolymer mortars. According to him geopolymer mortar specimes

manufactured by activation with higher alkali content resulted on lower water absorption and

water sorptivity and specimens with higher alkali content recorded higher residual compressive

strength. He also gave a report on variation of residual compressive strength with sorptivity. (6)

Prashant Agrawale.t al .presented their research on Effect of fineness of sand on the cost

and properties of mortar. In the present investigations, effect of the grading of river sand

particles has been investigated for a good Concrete mix. Sand has been sorted in three categories

i.e. Fine, Medium, and Coarse. These were mixed with coarse aggregate in different proportions

so as to keep the combined fineness modulus (all-in aggregate) more or less the same. Effect isstudied on concrete workability, cube strength, flexural strength and permeability. The results

indicate that with the change in fineness of sand, workability gets affected.

They concluded that fineness modulus has larger impact on 28 days Compressive &

Flexural Strength. Fineness Modulus has very little impact on permeability of concrete. The

results indicate that with the change in fineness of sand, workability gets affected. The details of

findings and its effect on compressive and flexural strength and permeability, influencing

durability are reported in this paper. (7)

2.3 Summary:-

In this chapter we studied the work carried by different researchers regarding influence of

sand grading on the properties of mortar. In the next chapter we will discuss about the

methodology and experimental work.


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Chapter 3

METHODOLOGY

3.1 Introduction:-

Sand plays an important role for the preparation of mortar. The objective of this report is

to check the effect of grading of sand on properties of mortar. In this chapter we shall discuss the

methodology and the experimental work.

3.2 Materials:-

For the present study locally available sand from Godavari river has been used. OPC 43

grade and potable water was used for the preparation of mortar.

3.3 Mix proportions:-

As our main intention is to find the effect of sand grading on the characteristics of the

mortar, therefore emphasis is given to use the different grades of sand and find their suitability in

different mix proportion of mortar.The mix proportions we have used are 1:3 and 1:6.

3.4 Process Operation: - (Methodology)

For the present study, the effect of sand grading on properties of mortar was investigated

To carry out the investigation different tests are required to be performed on the material. For the

present study, following tests are performed on the material:


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3.4.1 Tests on sand:

1. Sieve analysis (Grading of sand)

3.4.2 Tests on mortar:

1. Flow table test

2. Compressive strength

3. Water absorption test

3.4.3 Mixing of raw materials:-

The weighed quantity of Cement and sand were thoroughly mixed in dry state in a pan with

the help of a trowel. The required quantity of water is added in the mixture of cement and sand

After addition of the required quantity of water the mixture is thoroughly mixed with the help of

trowel in a pan. After mixing the mix initially with the trowel, the mixture is again mixed unti

the mass attained a uniform consistency.

3.4.4 Preparation of mortar blocks:-

Standard cement mortar cube moulds of size 70.7mm x70.7mm x 70.7mm were used for

preparation of blocks. The mix was placed in the cube mould and was compacted properly by

rod. Excess paste was hand finished. The mould was filled in three layers and each layer was

compacted properly.


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3.4.5 Method of curing:-

The blocks were taken out from the moulds after 24 hours. Then the moulds were placed

in gunny bags for curing in water tank. Then it is tested after 7 days, 14 days and 28 days of

curing.

3.5 Experimental Work:-

As discussed in the art 3.4, different tests are required to be performed on the material

Now we will discuss the tests and the experimental work.

3.5.1 Tests on sand: - (Sieve analysis)

The sand sample is taken in suitable quantity. The sample is sieved through a set of sieves

arranged in descending order of their sieve sizes from 4.75mm to 75 micron IS sieve. The sand is

sieved with the help of sieve shaker for 5-10 minutes. Then the sand retained on each sieve is

taken out. According to the requirement of the quantity of sand in a particular sieve, the sieving

have been done various times to get the required quantity.

For the determination of different grading of sand, we have done sieve analysis

analytically on the basis of fineness modulus as per recommendations.


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Following are the suggested recommendations of percentage of weight passing:-

Table no. 3.1: Grading limits for different sands (IS: 383-1970)

IS SEIVE SIZE

( mm )

COARSE SAND MEDIUM SAND FINE SAND

4.75 90-100 90-100 100

2.36 60-95 75-100 95-100

1.18 30-70 55-90 90-100

0.6 15-34 35-59 80-100

0.3 05-20 08-30 15-50

0.15 00-10 00-10 00-15

We have analytically find the individual weights on different sieve sizes for coarse sand,

medium and fine sand for 2Kg sample of sand according to the suggested recommendations of

% weight passing in the following way:-


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Plate no. 3.1 showing sieving of sands

Plate no. 3.2 showing Sieves of various sizes

Sieve Analysis of Natural Sand

A) COARSE SANDTable no. 3.2 Observation table for coarse sand


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IS

SEIVE

SIZE

WEIGHT

RETAINED

( grams )

CUMMULATIVE

% RETAINED

TOTAL

CUMMULATIVE

% RETAINED

WEIGHT

PASSING

%

SUGGESTED

4.75 128 6.4 6.4 93.6 90-100

2.36 410 20.5 26.9 73.09 60-95

1.18 449.5 22.475 49.375 50.625 30-70

0.6 604 30.2 79.575 20.425 15-34

0.3 310 15.5 95.075 4.925 05-20

0.15 81.5 4.075 99.150 0.85 0-10

From formula,

F.M = Total cumulative % retained / 100

= 356.47 / 100 = 3.565

As per recommendations, the fineness modulus of coarse sand ranges between 3.2 3.7

Thus, the sand available to us is coarse sand. As the naturally available sand comes under the

category of coarse sand, we have analytically done sieve analysis for medium and fine sand. The

sand which is found to be less in a particular sieve size should be added with that size of sand

until it comes in the range of recommended % retained and vice-versa.


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B) MEDIUM SANDTable no. 3.3 Observation table for medium sand

IS

SEIVE

SIZE

WEIGHT

RETAINED

( grams )

CUMMULATIVE

% RETAINED

TOTAL

CUMMULATIVE

% RETAINED

WEIGHT

PASSING

%

SUGGESTED

4.75 76 3.8 3.8 96.2 90-100

2.36 168 8.4 12.2 87.00 75-100

1.18 302.5 15.125 27.325 72.675 55-90

0.6 483 24.15 51.475 48.525 35-59

0.3 497.5 24.875 76.35 23.65 08-30

0.15 459 22.95 99.30 0.7 0-10

From formula,


= 270.45/ 100 = 2.70

As per recommendations, the fineness modulus of medium sand ranges between 2.62.9.

C) FINE SAND

Table no. 3.4 Observation table for fine sand


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IS

SEIVE

SIZE

WEIGHT

RETAINED

( grams )

CUMMULATIVE

% RETAINED

TOTAL

CUMMULATIVE

% RETAINED

WEIGHT

PASSING

%

SUGGESTED

4.75 0.00 0.00 0.00 100 100

2.36 2.00 0.10 0.10 99.9 95-100

1.18 2.50 0.125 0.225 99.775 90-100

0.6 3.50 0.175 0.40 99.6 80-100

0.3 995 49.75 50.15 49.85 15-50

0.15 770 38.50 88.65 11.35 0-15

From formula,


= 139.525 / 100 = 1.395

As per recommendations, the fineness modulus of fine sand ranges between 1.21.5.

3.5.2: Tests on mortar:-

a) Water requirement: -To determine the quantity of water required for the mix, we have done

the flow table test for both mix proportions of mortar with fine sand. The test was performed as

the procedure given below:-


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PROCEDURE:-

1. Oil the top surface of the table and inner surface of the mould.

2. Keep the mould on the table centrally and fill it with mortar in two layers.

3. Tamp each layer by tamping rod giving 25 blows.

4. Level the top surface and remove the excess mortar spread on the table

5. Lift the mould vertically and place aside.

6. Rise the table vertically by 12.5 mm and drop it (i.e. called jolting). Repeat this

procedure 10 times in 10 seconds.

7. Measure the diameter of spread mortar at the bottom in six directions. Find average

of these values to get spread diameter.


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Plate no. 3.3 showing flow table test apparatus

Plate no. 3.4 showing mortar specimen after removal of mould vertical


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3.5.2.1For 1:3 Mortars (Fine sand)

If we perform this test for coarse sand and medium sand, the water required as per result

would not be workable for fine sand as fine sand requires more quantity of water as compared to

coarse sand and medium sand. Thus water requirement have been determined for the fine sand.

For 1:3 mix proportions, we have performed test for various water content.

For 38% water content, the following values of spread diameters are obtained:-

d1 = 295mm

d2 = 285mm

d3 = 280mm

d4 = 277mm

d5 = 272mm

d6 = 271mm

From formula,

% flow = (spread dia.original dia.) / (original dia.)

Where spread dia. = 2 x [760 /2 - (d1+d2+d3+d4+d5+d6) / 6]

Therefore, spread dia. = 200mm

% flow = [(200100) / 100] x 100

= 100 %


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3.5.2.2 For 1:6 Mix (Fine sand)

If we perform this test for coarse sand and medium sand, the water required as per result

would not be workable for fine sand as fine sand requires more quantity of water as compared to

coarse sand and medium sand. Thus water requirement have been determined for the fine sand.

For 1:6 mix proportion, we have performed test for various water content.

For 41% water content, the following values of spread diameters are obtained:-

d1 = 300mm

d2 = 292mm

d3 = 281mm

d4 = 272mm

d5 = 269mm

d6 = 266 mm

From formula,

% flow = (spread dia.original dia.) / (original dia.)

Where spread dia. = 2 x [760 /2 - (d1+d2+d3+d4+d5+d6) / 6]

Therefore, spread dia. = 200mm

% flow = [(200100) / 100] x 100

= 100 %


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3.5.3 Compression Test:-

To study the effect of sand grading on the characteristics of mortar, we have performedcompression test. Compression test on the cubes of size 70.7x70.7x70.7 mm cubes was

performed to calculate the compressive strength of the cement mortar The procedure for the

compressive strength is as below:-

References :- 1) I.S. 4031-1968:- Method of physical tests of hydraulic cement (Part I)

2) I.S. 269-1976: Specification for Ordinary Portland Cement and low

heat cement.

Procedure:-

1) Weigh the required quantity ingredients accurately and according to the type of mix of1:3 and 1:6. ( For 3 cubes approximately 1600gm of mortar is required)

2) Mix the ingredients in dry state in a pan with the help of trowel. Mixing should be donetill the mortar becomes homogenous in colour. Add required quantity of water.

3) Mix the ingredients with the trowel thoroughly.4) Oil the inner surfaces of the moulds.5) Fill the moulds with the help of trowel. While filling the moulds they are compacted

with the help of a rod to remove the air form the mortar.

6) Smooth off the top surface by trowel to remove the excess mortar and place the cubes atroom temperature for 1 day.

7) Then remove the mortar cubes from moulds and then place the cubes in gunny bags forwater curing.

8) Test the cubes for their compressive strength after 7 days, 14 days and 28 days from theirdate of casting. For compression test U.T.M. shall be used.


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Plate No. 3.5 Mixing of Ingredients

Plate No. 3.6 Mortar blocks in moulds


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Plate No. 3.7 Water Curing of Mortar Cubes

Plate No. 3.8 Testing of Cubes Using U.T.M.


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3.5.4.1 Observations:-

1) Mix 1:3:-

Table no. 3.5: Observation table of coarse sand for compressive strength

Sr.

No.

Age

in

days

Surface

Area in

mm2

Compressive

Load in

Newton

Compressive

Strength in

MPa

Average

Comp.

Strength

in MPa

01 07 4998.49 125077.50 25.02

25.13

02 07 4998.49 126303.75 25.27

03 07 4998.49 125371.80 25.08

04 14 4998.49 156682.00 31.35

31.4105 14 4998.49 152488.00 30.51

06 14 4998.49 161854.00 32.38

07 28 4998.49 193341.60 39.25

38.6708 28 4998.49 190442.50 38.10

09 28 4998.49 193341.60 38.68


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Graph No. 3.1 Variation of Compressive Strength of coarse sand with age for M-1:3


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Table no. 3.6: Observation table of medium sand for compressive strength

Sr.

No.

Age

in

days

Surface

Area in

mm2

Compressive

Load in

Newton

Compressive

Strength in

MPa

Average

Comp.

Strength

in MPa

01 07 4998.49 114777.00 22.96

24.08

02 07 4998.49 119682.00 23.94

03 07 4998.49 127672.00 25.36

04 14 4998.49 151074.00 30.23

30.78

05 14 4998.49 157352.50 31.48

06 14 4998.49 153036.00 30.62

07 28 4998.49 166650.00 33.34

33.7608 28 4998.49 170748.50 34.16

09 28 4998.49 168899.00 33.79


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Graph No. 3.2 Variation of Compressive Strength of medium with age for M-1:3


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Table no. 3.7: Observation table of fine sand for compressive strength

Sr.

No.

Age

in

days

Surface

Area in

mm2

Compressive

Load in

Newton

Compressive

Strength in

MPa

Average

Comp.

Strength

in MPa

01 07 4998.49 75046.50 15.01

14.91

02 07 4998.49 74556.00 14.92

03 07 4998.49 73988.00 14.80

04 14 4998.49 98590.50 19.72

19.66

05 14 4998.49 96138.00 19.23

06 14 4998.49 100062.00 20.02

07 28 4998.49 143357.00 28.69

29.7008 28 4998.49 149255.00 29.86

09 28 4998.49 152654.00 30.54


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Graph No. 3.3 Variation of Compressive Strength of fine sand with age for M-1:3


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2) Mix 1:6:-

Table no. 3.8: Observation table of coarse sand for compressive strength

Sr.

No.

Age

in

days

Surface

Area in

mm2

Compressive

Load in

Newton

Compressive

Strength in

MPa

Average

Comp.

Strength

in MPa

01 07 4998.49 76327.00 15.27

15.23

02 07 4998.49 72878.00 14.58

03 07 4998.49 79226.00 15.85

04 14 4998.49 103986.00 20.80

20.32

05 14 4998.49 101138.00 20.23

06 14 4998.49 99571.50 19.92

07 28 4998.49 121113.50 24.23

24.3708 28 4998.49 118964.00 23.80

09 28 4998.49 125362.00 25.08


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Graph No. 3.4 Variation of Compressive Strength of coarse sand with age for M-1:6


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Table no. 3.9: Observation table of medium sand for compressive strength

Sr.

No.

Age

in

days

Surface

Area in

mm2

Compressive

Load in

Newton

Compressive

Strength in

MPa

Average

Comp.

Strength

in MPa

01 07 4998.49 67280.00 13.46

13.5402 07 4998.49 64730.50 12.95

03 07 4998.49 70978.50 14.20

04 14 4998.49 80422.00 16.09

15.7505 14 4998.49 76518.00 15.31

06 14 4998.49 79461.00 15.89

07 28 4998.49 96771.00 19.36

19.00

08 28 4998.49 99570.00 19.92

09 28 4998.49 102869.00 20.58


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Graph No. 3.5 Variation of Compressive Strength of medium sand with age for M-1:6


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Table no. 3.10: Observation table of fine sand for compressive strength

Sr.

No.

Age

in

days

Surface

Area in

mm2

Compressive

Load in

Newton

Compressive

Strength in

MPa

Average

Comp.

Strength

in MPa

01 07 4998.49 54134.00 10.83

10.2702 07 4998.49 51084.50 10.22

03 07 4998.49 48785.00 09.76

04 14 4998.49 66330.00 13.27

12.8705 14 4998.49 64280.50 12.86

06 14 4998.49 62381.00 12.48

07 28 4998.49 89373.00 17.88

17.80

08 28 4998.49 91172.50 18.24

09 28 4998.49 86224.00 17.25


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Graph No. 3.6 Variation of Compressive Strength of fine sand with age for M -1:6


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Graph No.3.7 Variation of Compressive Strength with age for M-1:3


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Graph No. 3.8 Variation of compressive strength with age for M-1:6


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3.5.4 Water Absorption Test:-

After casting the cubes of each mix proportion, the cubes were immersed in water and

after 28 days of curing the cubes were taken out of the curing tank and their saturated mass was

recorded after that the cubes were kept in oven at 85 0C and dried to a constant mass and dry

mass of the cubes was recorded. After that finding the difference between the saturated and dry

mass percentage water absorption was calculated. (6)

Plate no. 3.9 Cubes kept in oven for drying.


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3.5.4.1 OBSERVATIONS:-

a) FOR 1:3 MIX PROPORTION

Table no. 3.11: Observation table of water absorption for 1:3 proportions


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Graph No. 3.9 Variation of water absorption with grade of sand for M-1:3


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b) FOR 1:6 MIX PROPORTION:-

Table no. 3.12: Observation table of water absorption for 1:6 proportions


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Graph No. 3.10 Variation of water absorption with grade of sand for M-1:6


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Chapter 4

CONCLUSION

4.1Results and discussions:-

After performing various tests on the mortar samples with different proportions and

grading of sand, the following conclusions are drawn.

4.1.1 Compressive strength of mortar:-

Compressive strength of the mortar was determined by testing 70 mm cubes. Table no. 3.5

to 3.10 show the compressive strength of mortar cubes having different sand grading and

different proportion of cement to sand (i.e. 1:3 and 1:6). The results of compressive strength are

plotted in Graph No. 3.1 to 3.8.

It is observed that the strength of these blocks increases with age. From graph no. 3.1 to

3.6 we can see that coarse sand has more compressive strength than medium and fine sand in

both proportion of cement to sand. Graph no. 3.7 and 3.8 show comparative values of

compressive strength of mortar of different sand grading at 7, 14 and 28 days for 1:3 and 1:6

proportion respectively. Table no. 3.5 to 3.10 also shows that mortar with proportion 1:3 has

more strength than 1:6 proportions. The change in proportion of cement to sand caused a

considerable change in strength. Similarly when there is change in grading of sand definitely it

affects on the strength.Graph no. 3.7 shows for 1:3 mortar there is no appreciable change in the compressive

strength in the initial age i.e. 7 to 14 days for medium and coarse sand but appreciable change in

fine sand. Graph no. 3.8 shows that at 28 days there is no large variation in the compressive

strength for medium and fine sand but very large variation for coarse sand.


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4.1.2 Water absorption of mortar:-

Water absorption increases with increase in fineness of sand for cement mortars. Table

no.3.11 and 3.12 shows test results of water absorption of mortar cubes for different sand grading

and different proportions. Graph no. 3.9 and 3.10 show that fine sand absorbed more water than

coarse sand. Table no 3.11 and 3.12 show that fine sand absorbed more water than coarse sand.

Table no. 3.11 shows that when grading is changed from coarse to medium, there is little

variation in water absorption i.e. 0.11% but very large variation for fine sand i.e. 2.86% more

than medium sand for 1:3 proportion. Similarly table no. 3.12 shows that there is small variation

of water absorption (1.14%) when grading is changed from coarse to medium but water

absorption of fine sand is 3.67% more than medium sand. Water absorption of mortar cubes of

proportion 1:6 is more than proportion 1:3 so we can say that for a given consistency mortar with

fine sand requires more water i.e. with increase in fineness of sand water requirement increases.

4.2 Conclusions:-

Influence of sand grading on certain properties of mortar was examined OPC was used

with sands of different grading fine sand, medium sand and coarse sand.Based on the

experimental investigation reported in this study, following conclusions are drawn:

1. For a given consistency the compressive strength of mortar decreases with increase infineness of sand.

2. Water absorption of mortar increases with increase in fineness of sand. Fine sand requiresmuch more water than medium and coarse sand

3. The change in proportion of cement to sand caused a considerable change in strength.


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4.3 Future Scope:-

Mortar is used in masonry, decorative and protective plasters and in the production of

small-sized element such as bricks, mortar blocks, etc. Cement mortar are extensively used in

masonry, in damp-proof courses and for plastering and pointing. In view of application of mortar

we can say that mortar is very important part of any construction and there is lots of future scope

of mortar. There are limited studies on the influence of sand grading on the characteristics ofmortar so there is very large scope of this project.

All the mortar properties like compressive strength, water retentivity, workability, drying

shrinkage, water absorption and freezing-and-thawing resistance are very important to examine

the effect of sand grading on the properties of mortar. So all these properties of the mortar can be

investigated.

Further the effect of sand grading on the properties of mortar can be examined for different

proportions like 1:4 and 1:5.


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REFERENCES

1. E. Rivet and T. Ritchie. The influence of sand grading on mortar properties. NationalResearch Council Canada Division of Building Research Internal Report No. 201 of the

Division of Building Research, Ottawa July, 1960.

2. Kolias. The Influence of Size and Hardness of Sand Particles and Their Proportions onthe Friction Characteristics of Cement Mortars,Volume 16, Issue 2, December 1994.

3. G. De Schutter and A. M. Poppe. Quantification of the water demand of sand in mortarConstruction and Building Materials Volume 18, Issue 7, Pages 517-521, September

2004.

4. Jiong Hu and Kejin Wang. Effects of Aggregate on Flow Properties of Mortar.Proceedings of the 2005 Mid-Continent Transportation Research Symposium, Ames,

Iowa, August 2005.

5. B.V. Venkatarama Reddy and Ajay Gupta. Influence of sand grading on thecharacteristics of mortars and soilcement block masonry. Construction and Building

Materials 22, 16141623, 2008.
http://www.sciencedirect.com/science/journal/09500618http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235702%232004%23999819992%23509082%23FLA%23&_cdi=5702&_pubType=J&view=c&_auth=y&_acct=C000072761&_version=1&_urlVersion=0&_userid=7761544&md5=e4e95ecf9d1fab9810068ad2bf7b88dfhttp://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235702%232004%23999819992%23509082%23FLA%23&_cdi=5702&_pubType=J&view=c&_auth=y&_acct=C000072761&_version=1&_urlVersion=0&_userid=7761544&md5=e4e95ecf9d1fab9810068ad2bf7b88dfhttp://www.sciencedirect.com/science/journal/09500618


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6. Suresh Thokchom et.al. Effect of water absorption, porosity and sorptivity on durabilityof geopolymer mortars, ARPN Journal of Engineering and Applied Sciences, Vol. 4 No

7, September 2009.

7. Prashant Agrawal et.al. Effect of Fineness of Sand on the Cost and Properties ofConcrete, NBM Media.

8. Dr. S. V. Deodhar, Concrete Technology, P. No. 119-128.

9. Technical Teachers training institute, Chandigarh, Civil Engineering Material, TataMcGraw Hill Publishing Company Limited. P No. 3.32-3.25.

10.M. S. Shetty, Concrete Technology, S. Chand & Company Ltd. P. No. 91-93, 2007.


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