7399219 QC Tests for Road Works by Bhavanna Rao DV

8/3/2019 7399219 QC Tests for Road Works by Bhavanna Rao DV

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QUALITY CONTROL TESTS FOR ROAD WORKS

By Sri D.V.Bhavanna Rao,

Chief Engineer (R&B)QC and Member COT

1. PREPARATION OF DRY SOIL SAMPLES FOR VARIOUS TESTS(IS: 2720 PART 1 1983)

SCOPEThis standard (Part I) covers the method of preparation of dry samples from the bulk soilsample received from the field for various laboratory tests.

APPARATUS1 Wooden Mallet : For breaking soil clods.

2 Trays : For air drying of soil of suitable size and of non-rusting material.

3 Pulverizing Apparatus: Either mortar and rubber covered pestle or a mechanical device

consisting of a mortar and a power driven rubber covered pestle suitable for breaking up theaggregation of soil particles without reducing the size of the individual grains. Pestle andmortar made of soft wood may also be used.

4 Sampler : A suitable riffle sampler or sample splitter for quartering the samples (see IS:1607-1960 methods for dry sieving).

5 Sieves : Of sizes 75 mm, 63 mm, 37.5 mm, 19 mm, 13.2 mm, 9.5 mm, 6.7 mm, 4.75 mm,2.00 mm and 425 micron {see IS: 460(part I)-1978 specification for test sieves: part I wirecloth test sieves (second division)}.

6 Drying Apparatus : a) Drying oven: Thermostatically controlled with interior of noncorroding material to maintain the temperature between 1050 to

1100 C.b) Other suitable drying apparatus.

7 Balance: a) Capacity 10 kg and min. sensitivity 100 g.b) Capacity 1 kg and min. sensitivity 1 gc) Capacity 250 g and min. sensitivity 0.01 g

Preparation of Samples for Tests1 General : Soil sample as received from the field shall be dried in the air or in the sun. Inwet weather, a drying apparatus may be used in which case the temperature of the sampleshould not exceed 60C.The clods may be broken with a wooden mallet to hasten drying.The organic matter, like tree roots and pieces of bark should be removed from the sample.

Similarly, matter other than soil, like shells should also be separated from the main soil mass.A noting shall be made of such removals and their percentage of the total soil sample noted.When samples are to be taken for estimation of Organic content, lime content etc, totalsample should be taken for estimation without removing shells, roots etc.

2 Drying of the sample: The amount of drying depends up on the proposed tests to beconducted on the particular sample. The type, temperature and duration of drying of soilsamples for different tests are given in table-I... When oven is used for drying, thetemperaturein the oven shall not exceed 110C (see note.). Chemical drying of samples should not beadopted for any tests.Note: Soils containing Organic or Calcareous matter should not be dried at temperature above 60C.


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3 Degree of Pulverization: The big clods may be broken with the help of wooden mallet.Further pulverization may be done in pestle and mortar. The pulverized soil shall be passedthrough the specified sieve for the particular test and the soil retained on that sieve shall beagain pulverized for sieving, this procedure should be repeated until on further attempts atpulverizing very little soil passes through the specified sieve. Care should be taken not to

breakup the individual soil particles (see table-I).

Table I Quantity of Soil Sample Required for Conducting the Tests.(Clauses 3.2, 3.3 & 4.1)

S.

NOTEST

TypeTemperature and

duration of drying.

Amount of soilsample required

for test.

Degree ofPulverization

(IS Sieve size)

Refer to partof IS 2720.

(1) (2) (3) (4) (5) (6)

i Water content Oven. 24 h As given in table 2 -- Part 2

ii Specific Gravity

Oven. 105 to 110oC

24 h

50 g for fine grainedsoils

400g for fine,medium and coarse

grained soils

2 mm

part 3/section1

part 3/section2

iiiGrain sizeanalysis

Air Drying As given in table 3 -- part 4

iv Liquid Limit do 270g 425 micron part 5

v Plastic Limit do 60g do Do

viShrinkage

FactorsAir Drying 100g 425 micron part 6

vii

Compactiona) Light

Compactionb)HeavyCompaction

c)Constant Mass

do

do

do

6 kg(15 kg if soil issusceptible to

crushing)do

2 kg

19 mm

19 mm

4.75 mm

part 7

part 8

part 9

viiiUn-confinedcompressive

strength.Oven 110

oC 5

oC 1 kg -- part 10

ixTriaxial

compression(Unconsolidated)

Do 1 kg / 5 kg -- part 11

x

Triaxial

compression(Consolidated)

do do -- part 12

xi Direct ShearAir Drying/Oven

110o

5o

C1 kg 4.75 mm part 13

xiiDensity Index

(RelativeDensity)

Oven, 105 to1100C

24 h

As per size ofparticle given below

75 mm 45 kg37.5 mm 12 kg19 mm 12 kg9.5 mm 12 kg4.75 mm 12 kg

--Part

14


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xiiiConsolidation

PropertiesAir Drying/Oven

110o

5o

C500g -- part 15

xiv CBR Air Drying 6 kg 19 mm part 16

xv Permeability Oven, 105 to1100

C24 h

2.5 kg (100 mm dia)/ 5 kg (200 mm dia)

9.5 mm part 17

xviField Moisture

equivalentAir Drying 15 g 425 microns part 18

xviiCentrifugemoisture

equivalentDo 10 g do part 19

xviii Linear Shrinkage Do 450 g do part 20

xix

Chemical Testsa)Total Soluble

Solids

b)Organic Matter

c)CalciumCarbonate

d) Cat ionexchangecapacity

e)silicaSesquioxide ratio

f)pH value

g)Total solubleSulphates

Oven, 105 to1100C

24 h

Air Drying

Oven, 105 to1100C

24 h

do

do

do

do

10 g

100 g

5 g

80-130 g

15 g

30 g

30 g

2 mm

do

--

--

---

425 microns

--

part 21

part 22

part 23

part 24

part 25

part 26

part 27

xx Vane ShearAir Drying/Oven

110o

5o

C250 g -- part 30

xxiNegative Pore

Water PressureDo 1 kg / 5 kg -- part 35

xxiiPermeability ofGranular soils

Air Drying / Oven110

0C 5

0C

1 kg / 5 kg -- part 36

xxiiisand equivalent

value110

oC 5

oC 1500 g 4.75 mm part 37

xxiv Direct Shear Air Drying up to 120 g above 4.75 mmpart 39/

section 1

xxv Free Swell Index Oven Dry 20 g 425 microns part 40


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xxviSwellingPressure

Air Drying / OvenDry

2 kg 2 mm part 41

Quantity of Sample1 The quantities of soil sample required for conducting various laboratory tests are given in

table-I for guidance.Note: - For actual quantities corresponding part of IS 2720 shall be referred.

2 When a smaller quantity has to be taken out of a bigger soil mass, representativesampling shall be done by quartering or riffling

Note: - In the case of coarse gravel or gravelly soils, quartering by forming a cone shall not be done.The entire sample shall be thoroughly mixed and spread on a flat surface. The sample sospread shall be divided in to four quadrants and diagonally opposite quadrants mixed. Thisprocess shall be repeated till the desired quantity of sample is obtained.

Table 2 Quantity of sample required for

determination of water content

Size of Particles morethan 90% passing

Minimum quantity of soilspecimen to be taken for the

test. Mass in Grams.

425 micron IS Sieve 25

2 mm IS Sieve 50

4.75 mm IS Sieve 200


19 mm IS Sieve 500


Depending upon the type, 100 to 200 g of the soil fraction passing the 2 mm IS Sieve will berequired for the determination of the distribution of particles below 63-micron size.

Determination of Soil Gradation

A. Dry Sieve Analysis

(for soil fraction retained on 4.75 mm sieve)

1. Prepare the sample by drying it in air or oven and bring it to room temperature.

2. Clean all the sieves to be used (40 mm, 25 mm, 20 mm, 10 mm, 4.75 mm)3. Weigh the required quantity of material from the prepared sample.

4. Place the sieves over a clean tray one over the other in the ascending order of size.

5. Shake the sieve with a varied motion, backwards and forwards, left to right, circular clockwiseand anti clockwise, and with frequent jerking, so that the material is kept moving over thesieve surfaces.

6. Do not force the material through the sieve by hand, except for sizes coarser than 20mm.

7. Break the lumps of fine particles, if any, with fingers against the side of the sieve.

8. Light brushing with a soft brush on the under side of sieve may be done to clear surface.

Table 3 Quantity of Soil required for grain size analysis

Maximum Size ofMaterialPresent in Substantial

Quantities

Mass to betaken for Test.

mm Kg

75 60

37.5 25

19 6.5

13.2 3.5

9.5 1.5

6.7 0.75

4.75 0.4


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9. Find the individual weight of material retained on each sieve and record.

10. Calculate the percentage by weight of the total sample passing each sieve and report. Theresults in the prescribed form.

B. Wet Sieve Analysis

(for soil fraction passing 4.75 mm sieve and retained on 75 micron sieve)

1. Take a portion of the sample prepared by drying in oven and brought to room temperature.

2. Soak the sample in water and leave it for soaking overnight.

3. Wash out the finer fraction passing through 75 micron sieve.

4. Then dry it in oven for 24 hours and sieve the dry particles and find the percentage of soilpassing through each sieve and report the results in the prescribed form.

2. Test for the Determination of Liquid Limit By Cone Penetration

Method-One Point Method IS: 2720 (Part 5)-1985Apparatus

1Cone Penetrometer It shall consist of a metallic cone with half angle of 150-3015 and30.5 mm coned length. It shall be fixed at the end of a metallic rod with a disc at the top of therod so as to have a total sliding weight of 80 0.5 g. The rod shall pass through two guides (toensure vertical movement), fixed to a stand as indicated in Fig. It shall confirm to IS: 11196-1985.Suitable provision shall be made for clamping the vertical rod at any desired height above thesurface of the soil paste in the trough. A trough 50 mm in diameter and 50 mm high internallyshall be provided.2 Balance sensitive to 0.01 g.

3 Containers non-corrodible and air-tight for moisturedetermination.4 Oven thermostatically controlled with interior of non-corrodingmaterial to maintain the temperature between 1050C and 1100C.Soil Sample A soil sample weighing about 150 g from thethoroughly mixed portion of the soil passing 425 micron IS Sieveobtained in accordance with IS: 2720 (Part -1) 1983 shall betaken.

Procedure About 150 g of the soil specimen obtained as in 3.2shall be taken and worked into a paste with addition of distilledwater. In case of clayey soils, it is recommended that the soil is keptwet and allowed to stand for a sufficient time (24 hours) to ensureuniform distribution of moisture. The wet soil paste shall then be

transferred to the cylindrical trough of the cone Penetrometerapparatus and leveled up to the top of the trough. The Penetrometershall be so adjusted that the cone point just touches the surface ofthe soil paste in the trough. The scale of the Penetrometer shall then

be adjusted to zero and the vertical rod released so that the cone is allowed to penetrate into thesoil paste under its weight. The penetration shall be noted after 5 seconds from the release of thecone. If the penetration is less than 16 mm, the wet soil from the trough shall be taken out and morewater added and thoroughly mixed.The test shall then be repeated again till a penetration between 16 mm and 26mm is obtained. The exact depth of penetrationbetween these two values obtained during the test shall be noted. Themoisture content of the corresponding soil paste shall be determined in accordance with IS: 2720 (Part -2) - 1973.

Computations The water contentis determined for the accepted trial. The liquid limit iscomputed from the following relationship


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WL = W c + 0.01 (25 D) (W c + 15)

Where WL = liquid limit of the soil,Wc = moisture content of soil paste corresponding to penetration of Dand D = depth penetration of cone obtained in mm.Report1 The results of observations of the test shall be recorded suitably.

2 The liquid limit should be reported to the nearest whole number. The history of the soil sample,that is, natural state, air-dried, oven dried or unknown, the method used for the test and theperiod of soaking allowed after mixing of water to the soil shall also be reported.

3. Determination of Liquid Limit of Soil by Cassagrandhe method.

Liquid Limit (LL)

1. Take 120 gm of soil passing IS: 425 micron sieve.

2. Mix it with distilled water to form a paste.

3. Place a portion of the paste in the cup of the apparatus.

4. Level the specimen to half the cup.

5. Cut the paste with the standard grooving tool along the centre line.

6. Start rotating the handle at 2 revolutions per second.

7. Count number of blows till two parts of the sample come into contact at the bottom of thegroove (along a distance of 12 mm).

8. Record the number of blows and determine m.c. of the sample taken near the closed groove.

9. Repeat the test by changing the m.c. so that number of blows to close the groove is from 35to 10.

10. Plot a graph between log (number of blows) and moisture content and fit a straight line.

11. Read the m.c. corresponding to 25 number of blows from the graph. This gives the LiquidLimit of the soil.

4. Test for the Determination of Plastic Limit

Apparatus1 Porcelain Evaporating Dish about 12 cm in diameter.

OrFlat Glass Plate 10 mm thick and about 45 cm square or larger.IS: 2720 (Part 5) 1985

2 Spatula flexible, with the blade about 8 cm long and 2 cm wide.Or

Palette Knives two, with the blade about 20 cm long and 3 cm wide (for use with flat glassplate for mixing soil and water).

3 Surface for Rolling ground glass plate about 20 x 15 cm.4 Containers airtight to determine moisture content.5 Balance sensitive to 0.01 g.

6 Oven thermostatically controlled with interior of non-corroding material to maintain thetemperature between 1050C and 1100C.

7 Rod - 3 mm in diameter and about 10 cm long.

Soil Sample A sample weighing about 20 g from the thoroughly mixed portion of the materialpassing 425 micron IS Sieve, obtained in accordance with IS: 2720 (Part I)-1983* shall be taken.


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When both the liquid limit and the plastic limit of a soil are to be determined, a quantity of soilsufficient for both the tests shall be taken for preparation of the soil. At a stage in the process ofmixing of soil and water at which the mass becomes plastic enough to be easily shaped into aball, a portion of the soil sample in the plastic state should be taken for the plastic limit test.

Procedure The soil sample shall be mixed thoroughly with distilled water in an evaporatingdish or on the flat glass plate till the soil mass becomes plastic enough to be easily moulded withfingers. In the case of clayey soils, the plastic soil mass shall be left to stand for a sufficient time(24 hours) to ensure uniform distribution of moisture throughout the soil mass(See above Para).A ball shall be formed with about 8 g of this plastic soil mass and rolled between the fingers andthe glass plate With just sufficient pressure to roll the mass into a thread of uniform diameterthroughout its length. The rate of rolling shall be done till the threads are of 3 mm diameter. Thesoil shall then be kneaded together to a uniform mass and rolled again. This process of alternaterolling and the soil can no longer be rolled into a thread. The crumbling may occur when thethread has a diameter greater than 3 mm. This shall be considered a satisfactory end point,provided the soil has been rolled into a thread 3 mm in diameter immediately before. At no timeshall attempt be made to produce failure at exactly 3 mm diameter by allowing the thread to

reach 3 mm, then reducing the rate of rolling or pressure or both, and continuing the rollingwithout further deformation until the thread falls apart. The pieces of crumbled soil thread shall becollected in an air-tight container and the moisture content determined as described in IS: 2720(Part II)-1973*.

Report

1 The observations of test should be recorded suitably.

2 The moisture content determined as above, is the plastic limit of the soil. The plastic limit shall be determined for atleast three portions of the soil passing 425 micron IS Sieve. The average of the results calculated to the nearest wholenumber shall be reported as the plastic limit of the soil.

3 The history of the soil sample (that is, natural state, air-dried, oven dried or unknown) and theperiod of soaking allowed after mixing of water to the soil shall also be reported.

5. Plasticity Index

Calculation : The plasticity index is calculated as the difference between its liquid limit andplastic limit.

Plasticity index (Ip) = liquid limit (WL) plastic limit (Wp).

Report : The difference calculated as indicated in 7.1 shall be reported as the plasticity index,except under the following conditions:

a) In the case of sandy soils plastic limit should be determined first. When plastic limitcannot be determined, the plasticity index should be reported as Np (non-plastic).

b) When the plastic limit is equal to or greater than the liquid limit, the plasticity index shallbe reported as zero.

6. Determination of Free Swell Index of SoilsIS: 2720 (Part 40): 1977

1. Take two samples of dry soil. 10 gm each

2. Take two 100 ml graduated glass cylinders.

3. Pour the soil sample in each cylinder

4. Fill distilled water in one cylinder and kerosene in the other cylinder upto 100 ml marks.

5. Remove the entrapped air by gently shaking or stirring with a glass rod.


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6. Leave the samples to settle and allow sufficient time (24 hours or more) for the soil samplesto attain equilibrium state of volume.

7. Read the final volume of soil in each cylinder.

8. Determine the differential free swell index Sd using the formulaVolume of soil in water - volume of soil in kerosene

Sd= x lOOVolume of soil in kerosene

9. If the value of Sd is 50 percent or more, the soil is expansive and not suitable for use asembankment fill material. (For EW-5(a))

Precautions1) Pour the soil specimen in both the graduated glass cylinder gently, so that no soil particle

remains stuck to the wall of the cylinder.2) Sufficient time should be given to both the soil specimen to attain the final equilibrium

position of volume without any future change in the soil volumes. This may take 24 hours ormore.

3) For highly swelling soils, the weight of soil specimen may be taken as 5g or cylinders of250ml. capacity may be used.

A relation between differential free swell (%) and degree of expansiveness of soil is given below:

Differential free swell (%) Degree of expansiveness

< 20 Low

20-35 Moderate

35-50 High

> 50 Very HighIf the degree of expansiveness of soil at a site is damageable to the structure to be constructedthere, it is recommended to take suitable measures for foundation design to the same. In suchcases, the foundation should be constructed under the supervision of a geotechnical engineer.

7. Determination of Field Density and Dry Unit WeightBy Sand Replacement Method

Object and scope. The object of the test is to determine the dry density of natural orcompact soil, in-place, by the sand replacement method.

Materials and equipment: (i) Sand pouring cylinder of about 3 litre capacity, mountedabove a pouring cone and separated by a shutter cover plate and a shutter, (ii) Cylindricalcalibrating container, 10 cm internal diameter and 15 cm internal depth, fitted with flangeapproximately 5 cm wide and about 5 mm thick (iii) Glass plate, about 45 cm square and 1 cmthick, (iv) Metal tray with a central circular hole of diameter equal to the diameter of the pouringcone, (v) Tools for excavating hole, (vi) Balance accurate to 1 g, (vii) Container for water contentdetermination, (viii) Clean, closely graded natural sand passing the 1mm IS Sieve and retainedon the 600-micron IS Sieve.

Test Procedure(A) Determination of mass of sand filling the cone

1. Fill the clean closely graded sand in the sand pouring cylinder upto a height 1 cm below the

top. Determination the total initial mass of the cylinder plus sand (M1). This total initial mass

should be maintained constant throughout the tests for which the calibration is used.


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2. Allow the sand of volume equivalent to that of the excavated hole in the soil (or equal to thatof the calibrating container), to run out of cylinder by opening the shutter. Close the shutterand place the cylinder on glass plate.

3. Open the shutter and allow the sand to run out. Close the valve when no further movement ofsand is observed. Remove the cylinder carefully. Weigh the sand collected on the glass

surface. Its mass (M2) will give the mass of sand filling the pouring cone. Repeat this step atleast three times and take the mean mass (M2). Put the sand back into the cylinder, to havethe same constant mass (M1).

(B) Determination of bulk density of sand4. Determine the volume (V) of the calibrating container by filling it with water full to the brim

and finding the mass of water. This volume should be checked by calculating it from themeasured internal dimensions of the container.

5. Place the sand-pouring cylinder concentrically on the top of the calibrating container, afterbeing filled to constant mass (M1 ). Open the shutter and permit the sand to run into thecontainer. When no further movement of sand is seen, close the shutter. Remove the pouringcylinder and find its mass (M3) to nearest gram.

6. Repeat step (5) at least thrice and find the mean mass M3. Put the sand into the sand-pouring cylinder.

(C) Determination of dry density of soil in-place7. Expose about 45 cm square area of the soil to be tested and trim it down to level surface.

Keep the tray on the level surface and excavate a circular hole of approximately 10 cmdiameter and 15 cm deep and collect all the excavated soil in the tray. Find the mass (M) ofthe excavated soil.

8. Remove the tray, and place the sand-pouring cylinder, so that the base of the cylinder

concentrically covers the hole. The cylinder should have its constant mass M1. open theshutter and permit the sand to run into the hole. Close the shutter when no further movement

of the sand is seen. Remove the cylinder and determine its mass (M4).Keep a representative sample of the excavated soil for water content determination.

Tabulation of observations. The observations are tabulated as illustrated in Table 3.10.

TABLE 3.10 Data and Observation Sheet for Determination of DryDensity by Sand Replacement Method

(a) Determination of Mass of sand in the cone

1. Mass of sand (+cylinder) before pouring M1 10550 g2. Mean mass of sand in cone M2 445 g

(b) Determination of bulk density of sand

3. Volume of calibrating container V 1000 ml

4. Mean mass of sand (+cylinder) after pouring M3 8655 g5. Mass of sand filling calibrating container = M1 - M3 - M2 1450 g6. Bulk Density of sand S =1450 / 1000 1.45 g/cm

3(c) Bulk density of soil

7. Mass of wet soil from the hole M 2234g8. Mass of sand (+cylinder) after pouring in the hole M4 8512g9. Mass of sand in the hole = M1 - M4 - M2 1593g10. Bulk density of soil() = 2234 / 1593 X 1.45 2.03 g/cm

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(d) Water content determination

11. Container No 11

12. Mass of container + wet soil 62.48 g

13. Mass of container + dry soil 57.76 g

14. Mass of container 21.43 g15. Mass of dry soil 36.33 g


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16. Mass of water 4.72 g

17. Water content (w) Ratio 0.13

18. Dry density d =_ _ _2.03_1+w 1+0.13

1.8 g/cm3

Reference to Indian standard: IS: 2720-1974 (Part XXVIII) by sand replacement method):

8. Determination of Compaction Properties

Object and scope. The object of the experiment is to determine the relationship between watercontent and dry density of soil using Standard Proctor Test (light compaction) or Modified ProctorTest (heavy compaction), and then to determine the optimum water content and thecorresponding maximum dry density for a soil. The test also covers the determination ofrelationship between penetration resistance and water content for the compacted soil.

(a) Light Compaction (Standard Proctor Test)

Materials and Equipment. (i) Cylindrical metal mould of capacity 1000cc, with an internaldiameter of 1000.1 mm and an internal effective height of 127.30.1 mm, or mould of capacity2250 cc, with an internal diameter 1500.1 mm and an internal effective height of 127.30.1 mm,

each mould fitted with a detachable base and a removable extension (collar) approximately 60mm high (ii) Metal rammer, 50 mm diameter circular face, weighing 2.6 kg and having drop of310 mm (iii) Steel straight edge (iv) 20 mm and 4.75 mm IS sieves (v) Balances, 10 kg capacitysensitive to 1 g, and 200 capacity sensitive to 0.01 g (vi) Thermostatically controlled oven (105 1100C) (vii) Water content containers (viii) Mixing equipment, such as mixing pan, spoon, trowelspatula etc. (ix) Measuring cylinder of glass, 100 ml capacity (x) Sample extruder (optional).

Test Procedure

1. Take about 18 Kg of air dried sample for 1000 cc mould (40 Kg for 2250 cc mould) .Sieve the soil through 20mm and 4.75mm IS Sieves and calculate the ratio of fractionpassing 20mm IS Sieve and retained on 4.75mm IS Sieve. Use 100mm dia mould if

percentage retained on 4.75mm sieve is less than 20, and 150mm dia if soil percentageretained on 4.75mm sieve is more than 20. Discard the soil retained on 20mm sieve. Addenough water to bring its water content to about 7 per cent (sandy soils) or 10 percent (clayeysoils) less than the estimated optimum moisture content. Keep this soil in an air tight containerfor about 20 hours, for maturing.

2. Clean the mould and fix it to the base. Take the empty mass of the mould and the base,nearest to 1 g.

3. Attach the collar to the mould. The inside of the mould may be greased thoroughly.

4. Mix the matured soil thoroughly. Take out about 2 kg of the soil and compact it in the mouldin three equal layers, each layer being given 25 blows from the rammer weighing 2.6 kg dropping

from a height of 310 mm, if 1000 ml mould is used. If however, the 2250 ml mould is used, about5 kg of soil should be taken and should be compacted in three equal layers, each layer beinggiven 56 blows from the rammer weighing 2.6 kg dropping from a height of 310 mm. The blowsshould be uniformly distributed over the surface of each layer. Each layer of compacted soilshould be scored with a spatula before putting the soil for the succeeding layer. The amount ofsoil used should be just sufficient to fill the mould leaving about 5 mm to be struck off when collaris removed. Find the penetration resistance of compacted soil, using the Proctors needle.

5. Remove the collar, and cut the excess soil with the help of a straight edge. Clean the mouldfrom outside, and weigh it to the nearest gram. Eject out the soil from the mould, cut it in themiddle and keep a representative soil specimen for water content determination.

6. Repeat steps 4 and 5 for about five or six times, using a fresh part of the soil specimen andafter adding a higher water content than the proceeding specimen.


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Fig.a Fig.b

Tabulation of observations. The observations are tabulated as illustrated in Table below.

Table : Data And Observation Sheet For Proctors Test (Light Compaction)

Determination No. 1 2 3 4 5 6 7

(a) Density

Mass of mould + compacted soil (g)6607 6644 6723 6795 6837 6842 6829

Mass of mould (g) 4944 4944 4944 4944 4944 4944 4944

Mass of compacted soil (g) 1663 1720 1779 1851 1893 1898 1885Bulk density () g/cm

3 1.76 1.82 1.88 1.96 2.00 2.01 1.99

Dry density (d) g/cm3 1.55 1.57 1.58 1.64 1.63 1.62 1.58

(b) Water content Container No. 23 94 8 9 159 71 10

Mass of container + wet soil (g) 45.3 59.9 38.8 52.2 46.8 45.6 44.9

Mass of Container + dry soil (g) 42.5 54.7 36.2 47.4 42.2 41.3 40.2

Mass of water (g) 2.8 5.2 2.6 4.8 4.4 4.3 4.7

Mass of container (g) 22.5 22.9 22.5 22.6 23.1 22.9 22.5

Mass of dry soil (g) 20.0 31.8 13.7 24.8 19.3 18.4 17.7

Water content (w) (%) 13.9 16.3 18.8 19.4 22.8 23.4 26.6

Calculations: 1. The dry density of the compacted soil is calculated as follows:

d = (1+w)

A curve showing the relationship between dry density and water content is plotted. The watercontent corresponding to the maximum dry density is found from the curve. For the datatabulated above, the optimum water content is found to be 20% corresponding to maximum drydensity of 1.64 g/cm3. The corresponding dry unit weight = 1.64 x 9.81 = 16.09 kN/m3.2. The voids ratio for each determination is found from the equation:

e = G w - 1

d

3. On the same plot, a curve is drawn between penetration resistance and water content (Fig. b).


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(b) Heavy Compaction (Modified Proctors Tests)The equipment required for the heavy compaction test is the same as that required for the lightcompaction except that the rammer has a falling mass of 4.89 kg and has a drop of 45 cm. Thesoil is compacted in five equal layers, instead, of three. Each layer is given 25 blows of the

rammer if the 1000ml mould is used, and 56 blows if 2250cc mould is used.

9. Determination of California Bearing Ratio Value As per IS: 2720 (Part-16) -1979

1. Concept and SignificanceCalifornia Bearing Ratio (CBR) test originally developed by California Division of

Highways (U.S.A) is one of the most commonly used methods to evaluate the strength ofsubgrade soil for design of pavement thickness. CBR value as defined by IS: 2720 (Part XVI)-1979 is the ratio of the force per unit area required to penetrate a soil mass with a circularplunger of 50 mm diameter at the rate of 1.25 mm/minute, to that required for correspondingpenetration of a standard material. Standard load is that load which has been obtained from testson a crushed stone whose CBR value is taken to be 100 per cent. The ratio is usually determined

for penetration of 2.5 mm and 5.0 mm. The results of this test cannot be related accurately withfundamental properties of the material but are useful in design of flexible pavements.

2. ObjectiveTo determine the California Bearing Ratio of the subgrade soil.

3. ApparatusThe apparatus as per IS: 2720 (Part XVI) 1979 comprises of the following:

(i) Mould.A metallic cylinder of 150 mm internal diameter and 175 mm height; provided with a detachable metalextension collar 50 mm in height. It also has a detachable perforated base plate of 10 mm thickness. Theperforations in the base plate do not exceed 1.5 mm in diameter.

(ii) Steel cutting collar, which can fit flush with the mould.

(iii) Spacer disc. A metal disc of 148 mm diameter and 47.7 mm in height.

(iv) Surcharge weights: One annular metal weight and slotted weights each of 2.5 kg and 147 mm in diameterwith a central hole 53 mm in diameter.

(v) Dial gauges. Two dial gauges reading to 0.01 mm.

(vi) IS sieves of sizes 47.5 mm and 20 mm.

(vii) Penetration plunger. A metallic plunger having a diameter of 50 mm and at least 100 mm long.

(viii) Loading machine with a capacity of at least 5000 kg and equipped with a platform that can move vertically ata rate of 1.25 mm/min.

(ix) Miscellaneous apparatus like mixing bowl, straight edge, scales, soaking tank, drying oven, filter paper,dishes and calibrated measuring jar.

Procedure

Preparation of test specimen.

1 Preparation of Undisturbed SpecimenFit to the mould, the steel cutting edge of 150 mm internal diameter. Push the mould into

the ground as gently as possible till the mould is full of soil. Remove the soil from sides andbottom. Trim the excessive soil from top and bottom.

2 Preparation of Remoulded SpecimenRemoulded samples are prepared such that the dry density obtained from proctor

compaction tests, the water content of remoulded samples is either the optimum water content orthe field moisture as the case may be, the remoulded sample are compacted either statically ordynamically. The test material should pass 20mm IS sieve and retained on 4.75mm IS sieve. Ifcoarser material is retained on 20mm sieve, it should be discarded and an equal amount ofmaterial retained on 4.75mm sieve and passing through 20mm sieve should be replaced.


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3 Statically Compacted Specimen

(i) Calculate the amount of soil required such that it fills the mould (excluding collar) at thedesired density after compaction.

(ii) Calculate the amount of water to be added to give desired water content.

(iii) Mix the soil thoroughly with water.

(iv) Fix the extension collar to the mould and clamp it to the base plate.

(v) Fix the mould with soil, gently pressing it with hands so that it does not spill out of themould.

(vi) Place a coarse filter paper over the leveled soil surface and then insert the space disc.

(vii) Place the assembly on the pedestal of compression machine and compact the soil untilthe top of the spacer disc is flush with the top of the collar.

4 Dynamically compacted specimen

(i) Sieve the material through 20 mm IS sieve

(ii) Take about 4.5 kg or more of representative sample for fine grained soils and about 5.5kg for granular soils in a mixing pan.

(iii) Add water to the soil in the quantity such that the moisture content of the specimen iseither equal to field moisture content or OMC as desired.

(iv) Mix together the soil and water uniformly.

(v) Clamp the mould along with the extension collar to the base plate.

(vi) Place the coarse filter paper on the top of the spacer disc.

(vii) Pour soil-water mix in the mould in such a quantity that after compaction about 1/5th ofthe mould is filled

(viii) Give 56 blows with the rammer weighing 2.6 kg dropping through 310 mm in three layers

(light compaction) or 4.89 kg dropping through 450 mm in 5 layers (heavy compaction)evenly spread on the surface.

(ix) Scratch the top layer of compacted surface. Add more soil and compact in similar fashion.Fill the mould completely in five layers.

(x) Remove the extension collar and trim off the excess soil by a straight edge

(xi) Remove the base plate, spacer disc and the filter paper and note down the weight ofmould and compacted specimen.

(xii) Place a coarse filter paper on the perforated base plate.

(xiii) Invert the mould containing compacted soil and clamp it to the base plate.

5. Testing the Specimen

(i) Place the mould containing the specimen, with base plate in position, on the testingmachine.

(ii) Place the annular weight of 2.5 kg on the top surface of soil.

(iii) Bring the penetration plunger in contact with soil surface and apply a load of 4 kg so thatfull contact between soil and plunger is established. This should be taken as zero load.

(iv) Place the remainder surcharge weight so that total surcharge weight equals to 5 kg.

(v) Set the reading of dial gauges to zero.

(vi) Apply load so that penetration rate is 1.2 mm per min. Record the load at penetration of0, 0.5, 1.0, 1.5, 2.0, 2.5, 4.0, 5.0, 7.5, 10.0 and 12.5 mm. The maximum load has to berecorded if it occurs at less than 12.5 mm.

(vii) Collect about 20 to 50 g of soil to determine the water content


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6. CBR Test on Soaked Specimen

To perform CBR test on soaked specimen, the sample excluding base plate and spacerdisc is weighed. A filter paper is placed on the sample with a perforated plate on it. Over it asurcharge weight 2.5 or 5 kg is placed and the sample is soaked in water tank for 4 days. The

sample is then allowed to drain off water in a vertical position for about 15 minutes. The sampleis weighed again to calculate the percentage of water absorbed. It is then tested following thenormal procedure.

7. Computation of Test Results(i) Plot the load penetration curve with the load as ordinate and penetration as abscissa.

Sometimes the initial portion of the curve is concave upwards due to surface irregularities. Insuch a case apply a correction. Draw tangent at the point of greatest slope. The point wherethis tangent meets the abscissa is the corrected zero reading of penetration.

(ii) From the curve, determine the load value corresponding to the penetration value at which theCBR is desired.

(iii) Compute CBR value as follows:

Test load corresponding to chosen penetration (PT)CBR value = x 100

Standard load for the same penetration (PS)Usually the CBR value is calculated for 2.5 mm and 5 mm penetration. Generally the

CBR value at 2.5 mm penetration will be greater than that at 5 mm and in such a case the formeris taken for design purposes. If the 5 mm value is greater the test is repeated, if the same resultsfollow, the CBR value corresponding to 5 mm penetration is adopted for design purposes.

Table : Standard Load for Different Penetration ValuesPenetration

mmUnit standardload kg (f)/cm

2

Total standardkg(f)

2.5 70 1370

5.0 105 2055

7.5 134 2630

10.0 162 3180

12.5 183 3600

Note: The test must always be performed on remoulded sample of soils in the laboratory. Where ever

possible the test specimen should be prepared by Static Compaction but if not possible Dynamic method


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may be used as an alternative. In-Situ tests are not recommended for design purpose as it is not possibleto satisfactorily simulate the critical conditions of dry density and moisture content in the field.

10. Determination of Specific Gravity and

Water Absorption of Aggregate

1. Wash a sample of aggregate of not less than 2000 gm to remove dust. Drain and place thesample in the density basket.

2. Immerse the basket in water at a temperature of 22C to 32C with at least 5cm cover ofwater above the top of the basket.

3. Immediately after immersion, remove the entrapped air from sample by lifting the basket25mm above the base of the tank and allow it to drop 25 times, at the rate of one drop persecond.

4. Keep the basket and aggregates completely immersed in water for 24 `/~ hours. then

weigh in water at temperature of 22C to 32C (W1).

5. Remove the basket and aggregates from water and allow to drain for few minutes.

6. Empty the aggregates from basket and return the empty basket into water.

7. Jolt the basket 25 times and weigh in water

8. Gently dry the surface of the aggregate by wiping with cloth. Spread the aggregates.expose to atmosphere but away from direct sunlight till they appear dry.

9. Take the weight of surface dry aggregates (W3).

10. Place the aggregates in oven at a temperature of 100C to 110C for 24 1/2 hours.

11. Remove the aggregates in oven, cool in air and weigh (W4).

12. W4i) Sp. Gravity = ----------------------

W3 - (W1 W2)

W4ii) Apparent Sp. Gravity = ----------------------

W3 - (W1 W2)

W3 W4iii) Water absorption (Percent of dry weight) = ---------------- X 100

W4

13. Report results in Form GB - 5.

11. Determination of Moisture Content of Aggregates

1. Clean the container thoroughly

2. Dry it and termine its empty weight (W1) with lid.

3. Take the required quantity of the aggregate sample in the container and place it


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loosely inside the container.

4. Close the container and determine its weight (W2)

5. Keep the container with the lid removed in an oven maintained at a temperatureof 110C 5C for 24 hours.

6. After drying. remove the container and allow it to cool to room temperature.

7. Determine weight of the dry sample with lid (W3)

8. Calculate the water content in percentage using the formula.W2 W3

W = ---------------- X 100W2 W3

9. Report the results in the prescribed Form.

Moisture Content of Aggregates

12.Determination of Flakiness Index and Elongation Index ValuesConcept and Significance:

Flakiness Index of an aggregate is the percentage by weight of particles in it whose leastdimension (thickness)is less than three fifths (3/5th) of their mean dimension. The test is notapplicable to sizes smaller than 6.3mm.

ObjectTo determine the flakiness of coarse aggregate sample

Apparatus1. Balance should have an accuracy of 0.10% of the weight of test sample

2. Metal gauge confirming to IS 2336 (Part I) 19773. I.S Sieves 63mm, 50mm, 40mm , 31.5mm ,25mm,20mm,16mm, 12.5mm , 10.0mm and

6.3mm.

Procedure1. The sample has to be carefully and properly sieved.

2. Nine fractions are to be collected with the following specifications:

Passing through I.S Sieve Retained on I.S Sieve60 mm 50 mm50 mm 40 mm

40 mm 31.5 mm31.5 mm 25 mm25 mm 20 mm20 mm 16 mm

16 mm 12.5 mm12.5 mm 10 mm10 mm 6.3 mm

3. Every Piece of each fractional sieve shall be gauged for a minimum thickness with thehelp of the ISI gauge or in bulk using a set of sieves having standard elongated slots.

4. Thus, each fraction is to be separated into 2 parts: One consisting of pieces which passthrough the corresponding slot in the standard gauge and the other consisting of pieces

which do not pass through the corresponding slot in the standard gauge.


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5. Each part is separately weighed. Sum of both the weights gives the total weight of eachfraction.

Observations and Calculations:

F l a k i n e s s I n d e x

Wt.of fraction of the sample

S.No PassedThrough

RetainedOn

Weight ingms

ThicknessGuage

Wt.of fractionPassing throughThickness guage

in gms

Allowable Percentage

1. 63.0 50.0 4030 63.0 - 50.0 3832. 50.0 40.0 11820 50.0 - 40.0 12173. 40.0 25.0 21880 40.0 - 25.0 2341

Total 37730 3941

Flakiness Index:( 3941/37730) x 100 = 10.44 % Not >15 %

ELONGATION INDEX: Elongation Index is weight of elongated particles divided by total non-

flaky Particles.The gauge length would be 1.8 times the mean size of aggregate. For an aggregate passing

through 50mm sieve but retained on 40mm sieve, the mean size is 45mm and limit for the lengthof 45, works out to be 1.8 x 45 = 81mm.

Elongation I n d e x

S.NoWeight ofNon-flakymaterial

Length GuageWt. of Fraction

Retained onAllowable PercentageLength gauge in gms

1. 3647 63.0 - 50.0 1262. 10603 50.0 - 40.0 273

3. 19539 40.0 - 25.0 676Total 33789 1075

Elongation Index = 1075 x 100(37730-3941)

= 1075/33789 x 100 = 3.18.

Flakiness + Elongation Index = 10.44 + 3.18 = 13.62 % (Not > 30%)

The Flakiness Index shall be less than 35% for coarse aggregates for concrete works(Clause.1007 of MOST Specification.)

The Flakiness Index shall be less than 25% for stone chipping.

The Combined Flakiness and Elongation Indices shall be less than 30% for combined mixaggregates (bituminous works)

13. Determination of Aggregate Impact Value

1. Concept and Significance.The property of a material to resist impact is known as Toughness. Due to movement of

vehicles on the road the aggregates are subjected to impact resulting in their breaking down in tosmaller pieces. The aggregates should therefore have sufficient toughness to resist theirdisintegration due to impact. This characteristic is measured by impact value test. The aggregate


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impact value is a measure of resistance to sudden impact or shock, which may differ from itsresistance to gradually applied compressive load.

2. ObjectiveTo determine the impact value of the road aggregate

3. Apparatus1. Testing Machine

2. Cylindrical steel cup

3. Metal Hammer

4. Tamping rod

5. Balance.

4. Procedure

The test sample consists of

Aggregate size 10.0mm to 12.5 mm .The

aggregates should be dried by heating at

100-110 C for a period of 4 hours and

cooled.

1. The Aggregates passing through12.5mm sieve and retained on 10.0mmsieve comprises the test material.

2. Pour the aggregates to fill about just1/3rd depth of measuring cylinder.

3. Compact the material by giving 25gentle blows with the rounded end of the tamping rod.

4. Add two more layers in similar manner , so that the cylinder is full.

5. Strike off the surplus aggregates.

6. Determine the net weight of the aggregates to the nearest gram (W1).

7. Raise the hammer until its lower face is 380mm above the surface of the aggregate sample inthe cup and allow it to fall freely on the aggregate sample. Give 15 such blows at an interval

of not less than one second between successive falls.8. Remove the crushed aggregate from the cup and sieve it through 2.36mm IS sieve until no

further significant amount passes in one minute. Weigh the fraction passing the sieve to anaccuracy of one gram (W2). Also weigh the fraction retained on the sieve.

9. Note down the observations in the pro-forma and compute the aggregate impact value.

10. The mean of two observations, rounded to the nearest whole number is reported as theaggregate Impact value.

5. Precautions.1. In the operation of sieving the aggregates through 2.36mm sieve the sum of weights

of fractions retained and passing the sieve should not differ from the original weight of

the specimen by more than one gram.


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6. Record of Observations and Calculations.

Tests on Bituminous Material14. Determination of Penetration Value of Bitumen (Specification No.136 of APSS)

1. Concepts and Significance.Penetration is a measurement of hardness or consistence of bituminous material. It is

vertical distance penetrated by the point of a standard needle into the bituminous material underspecific condition of load, time and temperature. This distance is measured in 1/10 th of amillimeter.

2. Objectives.1. To determine the consistency of bituminous material.

2. To assess the suitability of Bitumen for its use under different climatic conditions and typeof constructions.

3. Apparatus.1. Container: A flat-bottomed cylindrical metallic dish 55mm in diameter and 35mm in depth is

required. If the penetration is of the order of 225mm or deeper dish of 70mm and 45mmdepth is required.

2. Needle: A straight highly polished, cylindrical hard steel rod, as per dimensions given in fig.

3. Water bath: A water bath maintained at 25.0 + 0.1 C containing not less than 10 Lt. ofwater, the sample being immersed to a depth not less than 100mm from the top andsupported perforated shelf not less than 50mm from the bottom of the bath.

4. Penetration Apparatus: It should be with a calibrated accuracy upto 1/10th of a millimeter.

5. Thermometer: 0 to 44 degrees and readable up to 0.20 C.

6. Time Measuring device: With an accuracy + 0.1 sec.

4. Procedure1. Preparation of test specimen: Soften the material to a pouring consistency at a temperature

not more than 60 C for Tars and 90 C for Bitumen. Stir it thoroughly until it ishomogeneous and free from air bubbles and water. Pour the melt into the container to adepth at least 10 mm in excess of the expected penetration and allow it to cool to room

temperature. Then place it along with the transfer dish in the water bath at 25.0C + 0.1

and allow it to remain for 1 to 1 hour.


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2. Clean the needle with Benzene, dry it and load with the weight. The total moving loadrequires is100+0.25gms, including the weight of the needle carrier and super-imposedweights.

3. Adjust the needle to make contact with the surface of the sample.

4. Make the pointer of the dial to read zero or note the initial dial reading.5. Release the needle for exactly five seconds.

6. Adjust the penetration machine to measure the distance penetrated.

7. Make at least 3 readings at points on the surface of the sample not less than 10mm apartand not less than10mm from the side of the dish. (After each test return the sample andtransfer dish to the water bath and wash the needle clean with benzene and dry it).

5. Precautions

1. There should be no movement of the container while needle is penetrating into thesample.

2. The sample should be free from any extraneous matter.3. The needle should be cleaned with benzene and dried before each penetration.

6. Record of observations and calculations:

Example:

S.No. Details Test 1 Test2 Test3

1. Penetrometer dial reading

(i) Initial 0 0 84

(ii) Final 86 84 171

2. Penetration value 86 84 87

Mean penetration value = (86+84+87)/3 = 85.67 or Say 86Penetration at 25 degree C, 100g, 5seconds in 1/100 cm shall be as under for the differentgrades of materials (as per IS: 73-1961 Table-II).

Grade of material Penetration

S 35 30 40

S 45 40 50

S 65 60 70S 90 80 100

S 200 175 225

15. Determination of Open Flash Point and Fire Point of Bitumen

1. Concept and SignificanceThe flash point of a material is the lowest temperature at which the application of test flamecauses the vapours from the material momentarily catch fire in the form of a flash under specifiedconditions of test.

The fire point is the lowest temperature at which the application of test flame causes the material

to ignite and burn at least for 5 seconds under specified conditions of test.


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2. ObjectiveTo determine flash point and fire point of the bituminous material.

3. Apparatus1. Cup:- A handle is attached to the flange of the cup.

2. Stove.

3. Thermometer: which is having a range of 90 C to 370 C readable to 2 C.

4. Procedure.

1. Clean and dry all parts of the cup and its accessories thoroughly.

2. Fill the cup with the material to be tested up to the level indicated by the filling mark.

3. Insert the thermometer.

4. Light and adjust the test flame and apply heat such that the temperature rises at a rate of

5 6 C per minute.

5. Note the temperature at which a flash first appears at any point on the surface of thematerial.

6. Continue heating until the bitumen ignites and burns for 5 minutes. Record thistemperature as fire point.

Ex:

TestProperty

1 2 3Mean

Flash Point 185 188 179 184

Fire Point 238 240 234 237

Note: Paving bitumen shall not be heated beyond the flash point. For paving bitumen of all the

five grades (i.e, S.35 to S.200) the flash point is 175C.

16. Determination of Softening Point of Bitumen1. Heat the bitumen to a temperature between 125C and 150C.

2. Heat the rings at same temperature on a hot plate and place it on a glass plate coated withglycerine.

3. Fill up the rings with bitumen.

4. Cool it for 30 Minutes in air and level the surface with a hot knife.

5. Set the ring in the assembly and place it in the bath containing distilled water at 5C andmaintain that temperature for 15 Minutes.

6. Place the balls on the rings.

7. Raise the temperature uniformly at 5C per minute till the ball passes, through the ring.

8. Note the temperature at which each of the ball and sample touches the bottom plate of thesupport.

9. Temperature shall be recorded as the softening point of the bitumen.


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17. Determination of Ductility of Bitumen

1. The bitumen sample is melted to a temperature of 75c to 100c above the approximatesoftening point until it is fluid.

2. It is strained through IS sieve 30, poured in the mould assembly and placed on a brass

plate, after a solution of glycerine and dextrin is applied at all surfaces of the mouldexposed to bitumen.

3. Thirty to forty minutes after the sample is poured into the moulds, the plate assembly alongwith the sample is placed in water bath maintained at 27C for 30 minutes.

4. The sample and mould assembly are removed from water bath and excess bitumenmaterial is cut off by leveling the surface using hot knife.

5. After trimming the specimen, the mould assembly containing sample is replaced in waterbath maintained at 27c for 85 to 95 minutes.

6. The sides of the mould are then removed and the clips are carefully hooked on themachine without causing any initial strain.

7. The pointer is set to read Zero.

8. The machine is started and the two clips are thus pulled apart horizontally.

9. While the test is in operation, it is checked whether the sample is immersed in water indepth of at least 10mm.

10. The distance at which the bitumen thread breaks is recorded (in cm.) and reported asductility value. [Form BL-1(b)]

18. ELASTIC RECOVERY TESTAS PER APPENDIX 1 OF IRC: 53 2002

Prepare 3 test specimens for 1 sample as prescribed in IS: 1208 at 15C . Elongate thetest specimen to 10cm at the rate of 0.25 cm per minute. Immediately cut the test specimenin to 2 halves at the mid point using scissors, Keep the test specimen in water bath in anundisturbed condition

For one hour at specified temperature, Move the elongated half of the test specimen backin to position near the fixed half to just touch. Record combined length as X

Elastic Recovery (%) = (10-X)/10x100

19. Determination of Rate of Spread of BinderI. Cut the cotton pads to a size of 203 x 102 mm. making sure that. each pad is as uniform in

size as possible.

2. Attach the cut cotton pads to heavy wrapping paper using suitable adhesive, the amount ofadhesive applied, being the same on each pad. Leave sufficient area of wrapping paper onthe four sides uncovered.

3. Number the pads on the underside of the paper.4. Attach pieces of masking tape to the wrapping paper and tape, to the nearest 0.1 gm.

5. Weigh the cotton pads complete with wrapping paper and tape, to the nearest 0.1 gm.

6. Attach the pads to the metal sheets. Fold the uncovered paper under the metal sheet andsecure with tape. such that no uncovered paper is exposed.

7. Place the metal sheets with test pads. on the road way at such locations, that the tyres ofthe distributor will not run over the pads.

8. As soon as the bitumen distributor has passed. Remove the metal sheet and test pad fromthe pavement. Remove the absorbent pads and wrapping paper. Including masking tapefrom metal sheet,

9. Weigh each pad. Including wrapping paper and masking tape to nearest 0.1g.


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Tests On Sand.20. Determination of Bulkage of Sand (APSS 110).

Object:- This test covers the procedure of determining in the field, the amount surface moistureor Bulking in fine aggregates by displacement in water.

Bulking of sand:- Increase in bulk volume of a quantity of sand in moist condition over thevolume of the same quantity of sand when completely inundated.

Procedure: In a 250ml measuring cylinder pour the damp sand (consolidating by shaking) untilit reaches 200ml mark. Then fill the cylinder with water and stir the sand well.(Thewater shall be sufficient to submerge the sand fully). It will be seen the sandsurface is now below its original level. Suppose the surface is at the mark y ml, thepercentage of bulking of the sand shall be calculated from the following formula;

Bulking % = 100(200-y)/yNote: The percentage of bulking of sand shall be rounded off to the nearest whole number.Therefore the volume of sand used shall be more than the quoted volume by above % in thespecification.

21. Determination Of Silt Content (APSS 110).

Object: To determine the percentage ofsilt content.

Sand shall be durable and free from adherent coatings and organic matter and shallnot contain any appreciable amount of clay balls or pellets.

Procedure: A sample of sand to be tested shall be placed without drying in a200ml measuringcylinder. The size of sample shall be such that it fills the cylinder up to 100ml mark.Clean water shall be added over it up to 150ml mark. The mixture then shall beshaken vigorously and the contents allowed to settle for 3 hours. The height of siltvisible as settled layer above the sand shall be expressed as percentage of the heightof sand below.

Limits: Clay, Fine Silt & Fine dust in natural sand or crushed gravel sand should not more than4% by weight.

22. Determination of Fineness Modulus (APSS 110)An empirical factor obtained by adding total percentages of a sample of the aggregates retainedon each of the following series of sieves divided by 100.

Object: To determine the fineness modulus of sandThe sieves used are 150,300,600 Microns, 1.18, 2.36, 4.75, 10.0, 20.0, 40.0 mm andlarger increasing in the ratio of 2 to 1.

Ex:

Sl.No SieveDesignation WeightRetained(g) Cum. Wt.Retained(g) Cum Wt.Retained In % Cum Wt. PassingIn %1 10mm - - - 1002 4.75mm 1 1 0.02 99.983 2.36mm 45 46 1.06 98.944 1.18mm 583 629 14.49 85.515 600 1935 2564 59.05 40.95

6 300 1407 3971 91.45 8.55

7 150 334 4305 99.14 0.86

8 (-)150 37 4342 - -

TOTAL 265.21Fineness Modulus = Total Cum. Wt. Retained % : 265.21/100 = 2.65%

100Allowable Limits: 2.00 to 3.50 %


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TESTS ON BRICKSFirst Class Bricks: The tolerance on the specified dimensions shall not exceed + 3%Second Class Bricks: The tolerance on the specified dimensions shall not exceed + 8%Physical Characteristics: When tested in accordance with IS: 3495 1966 the Bricks shallconform to the requirements as follows:

23. Determination of Crushing Strength of Bricks

Object: To determine the crushing strength of Bricks (APSS 102)

Preconditioning: Remove the unevenness observed in the bed faces to provide two smoothand parallel faces by grinding. Immerse in water at room temperature for 24 hours. Remove the

specimen and drain out any surplus moisture, at room temperature. Fill the frog (Whereprovided) and all voids in the bed face, flush the cement mortar of grade (1 cement, 1 cleancoarse sand). Then cover it with wet jute bags for 24 hrs followed by immersion in clean waterfor 3 days. Remove and wipe out any traces of moisture.

Procedure: Place the specimen with flat faces horizontal and mortar filled face, facing upwardbetween two 3- ply plywood sheets each of 3mm thickness and carefully centered between theplates of the testing machine. Apply load axially at a uniform rate of 140 Kgs/Cm2 per minute tillthe maximum load at which the specimen fails to produce any further increase in the indicatorreading on the testing machine.Ex:

Note: The strength of a Brick decreases by about 25% when soaked in water.

24. Determination of Water AbsorptionObject: To determine water absorption of Bricks (APSS 102).

Pre-conditioning: Dry the specimen in a ventilated oven at a temperature of 100-110C till aconstant weight is obtained. Cool the specimen to room temperature and obtain its dry weight(W1).

Procedure: Immerse completely the dried specimen in clean water at temperature of 27 + 5 Cfor 24 hr. Remove the specimen and wipe out any traces of water with a damp cloth and weighthe specimen (W2). Complete the weighing in 3 minutes after the removal of specimen fromwater.

Water absorption: (W2 W1) x 100W1

Ex:

S.NoSize of Brick

(Cm)Dry weight

(g)Wet weight

(g)Weight ofwater (g)

% of waterAbsorption

1. 23x11x7 2047 2431 384 18.762. 23x11x7 2236 2643 407 18.203. 23x11x7 1974 2310 336 17.02

Average = 17.99 %

Note: Water absorption of Bricks after 24hr. immersion shall not be more than 20% by weight.

Sl. No Characteristics Requirements

1. Compressive strength Not less than 40 Kg/Cm2

2. Absorption after 24 hr immersion in cold water Not more than 20% by wt.

3. Efflorescence Not more than moderate

Sl. No.Load at failure

(Kg)

Area

(Cm

2

)

Compression

Strength (Kgs/Cm

2

)

Average Compression

Strength (Kgs/Cm

2

)1. 10,450 253 41.302. 10,600 253 41.50

41.40

Documents

7399219 QC Tests for Road Works by Bhavanna Rao DV