Arun Soil Lab Pvt.Ltd.
Geotech and Material Consultants
Ensure and Assure safety of the structures for a better
And safe place to live and work with strong foundation

Quality Consiousness is Our Core Concept

Certificate No. : TC-5382
NABL Accredited as per
ISO/IEC: 17025 - 2005

Material Testing for Quality Control
Coarse & fine Aggregate
ACCORDING TO IS: 2386-1963
  • Sieve analysis helps to determine the particle size distribution of the coarse and fine aggregates. This is done by sieving the aggregates . In this we use different sieves as standardized by the IS code and then pass aggregates through them and thus collect different sized particles left over different sieves.
  • This test is used to determine the particle shape of the aggregate and each particle shape being preferred under specific conditions.The significance of flakiness & elongation index is as follows;
  • The degree of packing of the particles of one size depends upon their shape.
  • Due to high surface area to volume ratio, the flaky and elongated particles lower the workability of concrete mixes.
  • Aggregates Quality should consist of naturally occurring (crushed or uncrushed) stones, gravel and sand or combination thereof. They should be hard, strong, dense, durable, clear and free from veins and adherent coating, and free from injurious amounts of disintegrated pieces, alkali, vegetable matter and other deleterious substances. As for as possible, flaky, scoriaceous and elongated pieces, pieces are avoided. Visual inspection of gravel and natural sand is necessary for presence of clay lumps, clay coating, silt, grading and shape, while for crushed aggregates and sand inspection is necessary for stone dust, flaky shape and grading. If clay dust silt or mud is present and not removed/reduce through washing, it may produce lower strength concrete. The presence of mica should be investigate in fine aggregate and should also make suitable allowances for the possible reduction in the strength of concrete or mortar. The aggregate should not contain harmful organic impurities, excess to the limit specified.
  • Specific gravity, a low specified gravity indicates to high porosity, which results in poor durability and low strength. The concrete density is greatly depending on the specific gravity. A porous should not be permitted, unless specified.
  • Bulk density of aggregates is the mass of aggregates required to fill the container of a unit volume after aggregates are batched based on volume. It depends on the packing of aggregate i.e. Either loosely packed aggregates or well dense compacted aggregates. In case, if the specific gravity of material is known, then it depends on the shape and size of particles. It is because, if all the particles are of same size than packing can be done up to a very limited extent. If the addition of smaller particles is possible within the voids of larger particles than these smaller particlesenhance the bulk density of the packed material. Shape of the particles also influence very widely, because closeness particles depends on the shape of aggregates.
  • The volume increase of fine aggregate due to presence of moisture content is known as bulking. Fine sand bulks more as compared to coarse sand. Extremely fine sand particularly the manufactured fine aggregate bulks as much as about 40%. The moisture present in aggregate forms a film around each particle. These films of moisture exert a force, known as surface tension, on each particle. Due to this surface tension each particles gets away from each other. Because of this no direct contact is possible among individual particles and this causes bulking of the volume.
  • Aggregate crushing value gives a relative measure of the resistance of an aggregate to crushing under a gradually applied compressive load. The aggregate crushing value should not exceed 45% for aggregate used for concrete other than for wearing surfaces, and 30 % for concrete for wearing surfaces, such as runways, roads for pavements.
  • Aggregate impact value gives a relative measure of the resistance of an aggregate to sudden shock or impact, As an alternative to crushing value, the aggregate impact value should not exceed 45% by weight for aggregates used for concrete other than for wearing surfaces and 30% by weight for concrete for wearing surfaces, such as runways, roads for pavements.
  • The Los Angeles (L.A.) abrasion test is a common test method used to indicate aggregate toughness and abrasion characteristics. Aggregate abrasion characteristics are important because the constituent aggregate in HMA must resist crushing, degradation and disintegration in order to produce a high quality HMA.
  • Ten percent fines value is a measure of the resistance of aggregate crushing subjected to loading and it is applicable to both weak and strong aggregate. This test is very similar to Aggregate Crushing Test in which a standard force 400kN is applied and fines material expressed as a percentage of the original mass is the aggregate crushing value.
  • The soundness test repeatedly submerges an aggregate sample in a sodium sulfate or magnesium sulfate solution. This process causes salt crystals to form in the aggregate’s water permeable pores. The formation of these crystals creates internal forces that apply pressure on aggregate pores and tend to break the aggregate. After a specified number of submerging and drying repetitions, the aggregate is sieved to determine the percent loss of material.
ACCORDING TO IS: 4031 - 1988
  • The basic aim is to find out the water content required to produce a cement paste of standard consistency. The principle is that standard consistency of cement is that consistency at which the Vicat plunger penetrates to a point 5-7mm from the bottom of Vicat mould.
  • Initial setting time is that time period between the time water is added to cement and time at which 1 mm square section needle fails to penetrate the cement paste, placed in the Vicat’s mould 5 mm to 7 mm from the bottom of the mould. Final setting time is that time period between the time water is added to cement and the time at which 1 mm needle makes an impression on the paste in the mould but 5 mm attachment does not make any impression.
  • Compressive strength of cement is determined by compressive strength test on mortar cubes compacted by means of a standard vibration machine. Standard sand (IS:650) is used for the preparation of cement mortar. The specimen is in the form of cubes 70.6mm*70.6mm*70.6mm.
  • This experiment is carried out to check the proper grinding of cement. The cement which is produced by an industry is checked for its quality, that either it is good for certain type of construction or it doesn’t posses that much strength. For example, for RCC and other heavy load bearing structures such as bridges it is essential that the cement which is being used in the concrete should have the ability to provide the required strength, while in the PCC structures it is not so much critical. The ability to provide strength of a certain type of cement is checked by finding the fineness of that cement, because the fineness of cement is responsible for the rate of hydration and hence the rate of gain of strength and also the rate of evolution of heat. If the cement is fine then greater is its cohesiveness, which is the property, required in the concrete because it gives compactness to the concrete. Usually cement loses 10% of its strength within one month of its manufacturing.
  • This test method covers determination of the fineness of hydraulic cement, using the Blaine air-permeability apparatus, in terms of the specific surface expressed as total surface area in square centimeters per gram, or square meters per kilogram, of cement.
  • In the soundness test a specimen of hardened cement paste is boiled for a fixed time so that any tendency to expand is speeded up and can be detected. Soundness means the ability to resist volume expansion. It is very essential that the cement after setting shall not undergo any appreciable change in volume, because change in volume after setting of cement causes
  • Cracks
  • Undue expansion, and as a result
  • Disintegration of concrete
  • Specific gravity of the cement is the ratio of the mass of a given volume of the cement to that of an equal volume of water at the same condition of temperature. Cement will absorb water, so to prevent this reaction kerosene should be used instead of water to be mixed with cement. For determining the specific gravity of hydraulic cement, dust, sand and other fine materials. The body holds approximately 250ml. The oval bulb in the neck holds 17ml. Volume below the bulb is graduated from 0 to 1.0ml in 0.1ml subdivisions, with an additional 0.1 subdivision below the 0 and above the 1.0ml mark. The neck is graduated from 18 to 24ml in 0.1ml subdivisions above the bulb (white graduations).
Physical Properties of Steel
ACCORDING TO IS: 1608 - 2005
  • A yield strength or yield point of a material is defined in engineering and materials science as the stress at which a material begins to deform plastically. Prior to the yield point the material will deform elastically and will return to its original shape when the applied stress is removed. Once the yield point is passed, some fraction of the deformation will be permanent and non-reversible.

  • Yield Strength (N/mm2 (kg/cm2) = Yield load in N (kg)/Area Cross section(mm2 or cm2)
  • Ultimate tensile strength (UTS), often shortened to tensile strength (TS) or ultimate strength,[1][2] is the maximum stress that a material can withstand while being stretched or pulled before failing or breaking. Tensile strength is distinct from compressive strength.

  • Ultimate Tensile Strength (N/mm2 (kg/cm2) = Maximum load in N (kg)/Area Cross section (initial) in sqmm. or sqcm,
  • Percent elongation quantifies the ability of an element or compound to stretch up to its breaking point. It is measured by dividing the change in length (up to the breaking point) by the original length, then multiplying by 100. Materials with a higher percentage elongation can stretch more before breaking.

  • Percentage Elongation = ((Lu-Lo)/Lo))*100 where , Lu =Final gauge length after fracture, Lo = Original gauge length (5.65vSo)
  • The difference between the original cross-sectional area of a test specimen before being subjected to tension and the area of its smallest cross section after rupture; expressed as a percentage of the original cross-sectional area of the specimen.

  • Percentage Reduction in area = ((So-Su)/So))*100 where , So =Original cross sectional area of gauge length, Lo = Minimum cross sectional area after fracture
BEND & REBEND TEST (IS: 1599 - 1985)
  • A bending test is a method for measuring stiffness and yield properties of certain materials. Bending tests for ductility provide a simple way to evaluate the quality of materials by their ability to resist cracking or other surface irregularities during one continuous bend. In certain cases the bending test can determine tensile strength.
SPECIFIC GRAVITY (IS: 1202 - 1978)
  • This test is done to determine the specific gravity of semi-solid bitumen road tars etc. The principle is that it is the ratio of mass of a given volume of bitumen to the mass of an equal volume of water, both taken at a recorded/specified temperature.
PENETRATION (IS :1203-1978)
  • Penetration value is a measure of hardness or consistency of bituminous material. It is the vertical distance traversed or penetrated by the point of a standard needle in to the bituminous material under specific conditions of load, time and temperature. This distance is measured in one tenths of a millimeter. This test is used for evaluating consistency of bitumen. It is not regarded as suitable for use in connection with the testing of road tar because of the high surface tension exhibited by these materials.
SOFTENING POINT (IS: 1205 - 1978)
  • The Softening Point of bitumen or tar is the temperature at which the substance attains particular degree of softening. It is the temperature in ºC at which a standard ball passes through a sample of bitumen in a mould and falls through a height of 2.5 cm, when heated under water or glycerine at specified conditions of test. The binder should have sufficient fluidity before its applications in road uses. The determination of softening point helps to know the temperature up to which a bituminous binder should be heated for various road use applications. Softening point is determined by ring and ball apparatus.
INDUSTRIAL VISCOSITY (IS: 1206 (Part 1) - 1978)
  • Viscosity denotes the fluid property of bituminous material and it is a measure of resistance to flow. At the application temperature, this characteristic greatly influences the strength of resulting paving mixes. Low or high viscosity during compaction or mixing has been observed to result in lower stability values. At high viscosity, it resists the compactive effort and thereby resulting mix is heterogeneous, hence low stability values. And at low viscosity instead of providing a uniform film over aggregates, it will lubricate the aggregate particles. Orifice type viscometers are used to indirectly find the viscosity of liquid binders like cutbacks and emulsions. The viscosity expressed in seconds is the time taken by the 50 ml bitumen material to pass through the orifice of a cup, under standard test conditions and specified temperature
ABSOLUTE VISCOSITY (IS: 1206 (Part 2) - 1978)
  • The basic absolute viscosity test measures the time it takes for a fixed volume of asphalt binder to be drawn up through a capillary tube by means of vacuum, under closely controlled conditions of vacuum and temperature. Although absolute viscosity is an improvement over the penetration test, it still only measures viscosity at one temperature and thus does not fully characterize an asphalt binder’s consistency over the expected range of construction and service conditions.
KINEMATIC VISCOSITY (IS: 1206 (Part 3) - 1978)
  • The kinematic viscosity of a liquid is the absolute (or dynamic) viscosity divided by the density of the liquid at the temperature of measurement. The 135° C (275° F) measurement temperature was chosen to simulate the mixing and lay down temperatures typically encountered in pavement construction. The basic kinematic viscosity test measures the time it takes for a fixed volume of asphalt binder to flow through a capillary viscometer under closely controlled conditions of head and temperature
DUCTILITY (IS: 1208 - 1978)
  • Ductility is the property of bitumen that permits it to undergo great deformation or elongation. Ductility is de?ned as the distance in cm, to which a standard sample or briquette of the material will be elongated without breaking. Dimension of the briquette thus formed is exactly 1 cm square. The bitumen sample is heated and poured in the mould assembly placed on a plate. These samples with moulds are cooled in the air and then in water bath at 27 °C temperature. The excess bitumen is cut and the surface is leveled using a hot knife. Then the mould with assembly containing sample is kept in water bath of the ductility machine for about 90 minutes. The sides of the moulds are removed, the clips are hooked on the machine and the machine is operated. The distance up to the point of breaking of thread is the ductility value which is reported in cm. The ductility value gets affected by factors such as pouring temperature, test temperature, rate of pulling etc
FLASH & FIRE POINT (IS: 1209 - 1978)
  • This test is done to determine the flash point and the fire point of asphaltic bitumen and fluxed native asphalt, cutback bitumen and blown type.
  • Flash Point – The flash point of a material is the lowest temperature at which the application of test flame causes the vapours from the material to momentarily catch fire in the form of a flash under specified conditions of the test.
  • Flash Point – 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 the test.
LOSS ON HEATING (IS: 1212 - 1978)
  • Loss on heating test determines the effect on asphaltic materials of heating in an oven under prescribed conditions. The results are reported in terms of change in sample mass and/or changes in selected properties such as viscosity, penetration and ductility as evidenced by test data taken before and after the oven cycle.
  • This method covers the procedure for determining the degree of solubility in trichloroethylene of bituminous materials containing little or no mineral matter. The sample is dissolved in trichloroethylene and filtered through whatman filter paper number five. The insoluble material is washed, dried and weighed.
  • The elastic recovery of a polymer modified asphalt cement is evaluated by the percentage of recoverable strain measured after elongation during a conventional ductility test. Unless otherwise specified, the test shall be made at the temperature of 77°F (25°C ± 0.5°) and with a speed of 50 mm/min. ± 5.0%.
Bituminous Mix Proportioning
ACCORDING TO : Section 500 of Specifications for Road and Bridge Works of Ministry of Road Transport and Highways
  • The bituminous mix is designed in the laboratory considering the following requirements as per Table 500 - 11 of Section 500 of Specifications for Road and Bridge Works of Ministry of Road Transport and Highways :
  • The stability of the mix corresponding to the design-binder content need be more than minimum specified value.
  • Flexibility or deformation at failure is to be within the specified range.
  • Void content of the design mix is to be within the specified range.
  • GRADATION OF AGGREGATE : Gradation of aggregate is one of the most important factors for the design of mixture.The gradation of final mix after blending of the aggregates and filler should be within the specified range as per the specifications of either the Indian Road Congress (IRC) or the Ministry of Road Transport and Highways (MORTH), Government of India.

  • VOLUMETRIC PROPERTIES : Fundamentally, mix design is meant to determine the volume of bitumen binder and aggregates necessary to produce a mixture with the desired properties. The properties that are to be considered, include the theoretical maximum specific gravity Gmm , the bulk specific gravity of the mix Gmb , percentage air voids VA, percentage volume of bitumen Vb, percentage void in mineral aggregate VMA and percentage voids filled with bitumen VFB.
  • Marshall stability of the bituminous mix design used in the laboratory has been specified by IRC and MoRTH Specifications for use in India.
  • Marshall Stability test is conducted on compacted 3 to 4 cylindrical specimens of bituminous mix of diameter 101.6 mm and thickness 63.5 mm. The load is applied perpendicular to the axis of the cylindrical specimen through a testing head consisting of a pair of cylindrical segments, at a constant rate of deformation of 51 mm per minute at the standard test temperature of 60°C.
  • The 'Flow Value' is the total deformation that the Marshall test specimen undergoes at the maximum load, expressed in mm units. The Marshall Stability value of a compacted specimen of bituminous mix indicates its resistance to deformation under applied incremental load and the flow value indicates the extent of deformation it undergoes due to loading or its 'flexibility'.
Concrete Mix Proportioning
ACCORDING TO IS: 10262 - 2009
  • Any of the the following shall be used with prior approval of the competent authority :
  • Ordinary Portland Cement conforming to IS: 269
  • Portland slag cement conforming to IS: 455 but with not more than 50 percent slag content
  • Rapid hardening Portland cement conforming to IS: 8041
  • High strength Portland cement conforming to IS: 8112
  • Coarse aggregate shall consist of clean, hard, strong, dense non porous and durable pieces of crushed stone, crushed gravel, natural gravel or a suitable combination therefore other approved inert material. It shall not contain pieces of disintegrated stones, soft, flaky elongated particles, salt alkali, vegetable matter or other deleterious materials in such quantities as to reduce the strength or durability of the concrete, or to attack the embedded steel. It shall comply with IS: 383
  • Fine aggregates shall consist of hard, strong, durable, clean particles of natural sand, crushed stone or crushed gravel or suitable combination of natural sand and crushed stone or gravel. They shall not contain dust, lumps, soft or flaky materials, mica and other deleterious materials in such quantities as would reduce the strength or durability of concrete or attack the embedded steel. Fine aggregates shall conform to IS: 383
  • Water used for mixing and curing shall be clean and free from injurious amounts of oils, acids, alkalis, salts, sugar, organic materials or other substances that may be deleterious to concrete or steel. Potable water is generally considered satisfactory for mixing concrete. As a guide the following concentrations represent the maximum permissible values :
  • To neutralize 100 ml sample of water using phenolphthalein as on indicator, it should not require more than 5 ml of 0.02 normal NaOH.
  • To neutralize 100 ml sample of water using methylorange as on indicator, it should not require more than 25 ml of 0.02 normal H2SO4.
  • Accelerator / Water Reducing / Superplasticizer / Air Entraining Admixture may be provided in conformity with IS: 9103
  • The determinations of the proportion of cement, aggregates and water to attain required strengths shall be made by designing the concrete mix. Such concrete shall be called only “Design Mix Concrete”. For prestressed concrete construction only “Design Mix Concrete” shall be used. The concrete mix shall be designed as per IS:10262 (Recommended Guidelines for Concrete Mix Design) to have a target mean strength defined as fck + 1.65 X SD .Maximum quantity of cement shall not be more than 540 Kg/cum of concrete.
Burnt Clay and Flyash Bricks
COMPRESSIVE STRENGTH (IS: 3495 (Part 1) - 1992)
  • PRECONDITIONING - Remove unevenness observed in the bed faces to provide two smooth and parallel faces by grinding.Immerse in water at room temperature for 21 hours. Remove the specimen and drain out any surplus moisture at room temperature. Fill the frog ( where provided ) and all voids in the bed face flush with cement mortar ( 1 cement, clean coarse sand of grade 3 mm and down ). Store under the damp jute bags for 24 hours followed by immersion in clean water for 3 days. Remove, and wipe out any traces of moisture.

  • PROCEDURE - Place the specimen with flat faces horizontal, and mortar filled face facing upwards between two 3-ply plywood sheets each of 3 mm thickness and carefully centered between plates of the testing machine. Apply load axially at a uniform rate of 14 N/mm² ( 140 kgf/cm² ) per minute till failure occurs and note the maximum load at failure. The load at failure shall be the maximum load at which the specimen fails to produce any further increase in the indicator reading on the testing machine.

  • NOTE - In place of plywood sheets plaster of Paris may be used to ensure a uniform surface for application of load.
WATER ABSORPTION (IS: 3495 (Part 2) - 1992)
  • PRECONDITIONING -Dry the specimen in a ventilated oven at a temperature of 105 to 115°C till it attains substantially constant mass. Cool the specimen to room temperature and obtain its weight ( MI ). Specimen warm to touch shall not be used for the purpose.

  • PROCEDURE - Immerse completely dried specimen in clean water at a temperature of 27 °C ± 2°C for 24 hours.Remove the specimen and wipe out any traces of water with a damp cloth and weigh the specimen. Complete the weighing 3 minutes after the specimen has been removed from water ( M2 ).Water absorption, percent by mass, after 24-hour immersion in cold water is given by the following formula:

  • Water Absorption (%) = (M2 - M1)/M1* 100
EFFLORESCENCE (IS: 3495 (Part 3) - 1992)
  • PROCEDURE -Place the end of the bricks in the dish, the depth of immersion in water being 25 mm. Place the whole arrangement in a warm ( for example, 20 to 30°C ) well ventilated room until all the water in the dish is absorbed by the specimens. and the surplus water evaporates. Cover the dish containing the brick with suitable glass cylinder so that excessive evaporation from the dish may not occur. When the water has been absorbed and bricks appear to be dry, place a similar quantity of water in the dish and allow it to evaporate as before. Examine the bricks for efflorescence after the second evaporation and report the results.

  • INTERPRETATION - The liability to efflorescence shall be reported as 'nil', 'slight', 'moderate', 'heavy' or 'serious' in accordance with the following definitions:

  • NIL - When there is no perceptible deposit of efflorescence.

  • SLIGHT - When not more than 10 percent of the exposed area of the brick is covered with a thin deposit of salts.

  • MODERATE - When there is a heavier deposit than under 'slight' and covering up to 50 percent of the exposed area of the brick surface but unaccompanied by powdering or flaking of the surface.

  • HEAVY - When there is a heavy deposit of salts covering 50 percent or more of the exposed area of the brick surface but unaccompanied by powdering or flaking of the surface.

  • SERIOUS - When there is a heavy deposit of salts accompanied bp powdering and/or flaking of the exposed surfaces.
WARPAGE (IS: 3495 (Part 4) - 1992)
  • PRECONDITIONING -Remove any dirt adhering to the surface of brick.

  • For Concave Warpage - Place the flat surface along the surface to be measured selecting the location that gives the greatest departure from straightness. Measure the greatest distance of the brick surface from the edge of straightness by a steel rule or wedge.

  • For Convex Warpage - Place the brick on the flat surface with the convex surface in contact with the flat surface. Measure the distance from Rat surface to the four corners of the brick, and take the maximum of four measurements.

  • INTERPRETATION -The higher of the distance measured shall be reported as warpage.
Paving Block
ACCORDING TO IS: 15658 - 2006
  • Dimensions and plan areas of the specimens shall be determined as described in Annex B. The blocks shall be stored for at least 24 hours in water at a temperature of 20°C ±5°C. The bearing plates of the testing machine shall be wiped clean. The specimens are aligned with those of the bearing plates.
  • The apparent compressive strength of individual specimen shall be calculated by dividing the maximum load (in N) by the plan area (in mm²). The Corrected compressive strength shall be calculated by multiplying the apparent compressive strength by the appropriate correction factor from Table given and below. The strength shall be expressed to the nearest 0.10 N/mm²
  • Square shaped specimens measuring 71.0 ± 0.5 mm shall be cut from the block (specimen selected) and testing surface of the specimen shall be centrally Loaded with 294 3N on grinding disc. Disc shall be stopped after one cycle of 22 revolutions at a speed of 30 rpm. the specimen turned 90 in clockwise direction and repeat the test for 16 cycle.
  • The Flexural strength of the specimen shall be calculated as-
  • Fb = 3pl / 2bd²
  • Fb = Flexural Strength, in N/mm²;
  • p = Maximum Load, in N;
  • l = Distance between central lines of the supporting rollers, in mm;
  • b = Average width of block, in mm
  • d = Average thickness, in mm
  • The maximum load p shall be reported as the breaking load, nearest to 1 N
Soil for Road Work
GRAIN SIZE ANALYSIS (IS: 2720 (Part 4) - 1985)
  • The grain size analysis is widely used in classification of soils. The data obtained from grain size distribution curves is used in the design of filters for earth dams and to determine suitability of soil for road construction, air field etc. Information obtained from grain size analysis can be used to predict soil water movement although permeability tests are more generally used.
ATTERBERG LIMIT (IS: 2720 (Part 5) - 1985)
  • The Atterberg limits are a basic measure of the critical water contents of a fine-grained soil, such as its shrinkage limit, plastic limit, and liquid limit. As a dry, clayey soil takes on increasing amounts of water, it undergoes dramatic and distinct changes in behavior and consistency. Depending on the water content of the soil, it may appear in four states: solid, semi-solid, plastic and liquid. In each state, the consistency and behavior of a soil is different and consequently so are its engineering properties.
SHRINKAGE FACTORS (IS: 2720 (Part 6) - 1972)
  • The soil shrinkage is defined as the specific volume change of soil relative to its water content and is mainly due to clay swelling properties.
COMPACTION OF SOIL (Part 7 - 1980 & Part 8 - 1983)
  • Soil compaction is defined as the method of mechanically increasing the density of soil. In construction, this is a significant part of the building process. If performed improperly, settlement of the soil could occur and result in unnecessary maintenance costs or structure failure. Almost all types of building sites and construction projects utilize mechanical compaction techniques.
  • The california bearing ratio test is penetration test meant for the evaluation of subgrade strength of roads and pavements. The results obtained by these tests are used with the empirical curves to determine the thickness of pavement and its component layers. This is the most widely used method for the design of flexible pavement.
PERMEABILITY OF SOIL (IS: 2720 (Part 17) - 1986)
  • The soil permeability is a measure indicating the capacity of the soil or rock to allow fluids to pass through it. The permeability coefficient can be determined in the laboratory using falling head permeability test, and constant head permeability test. The knowledge of this property is much useful in solving problems involving yield of water bearing strata, seepage through earthen dams, stability of earthen dams, and embankments of canal bank affected by seepage, settlement etc.
FREE SWELL INDEX (IS: 2720 (Part 40) - 1977)
  • The clay and specially the black cotton soils have a tendency to swell in small or more proportion when submerged in water. Free swell or differential free swell also termed as free swell index, is the increase in volume of soil with out any external constraint when subjected to submergence in water.
Cement Concrete & Blocks
  • Three blocks shall be dried to constant mass in a suitable oven heated to approximately 1000C. After cooling the blocks to room temperature, the dimensions of each block shall be measured in centimeters to the nearest millimeter and the overall volume computed in cubic centimeters. The blocks shall then be weighted in kilograms to the nearest 10 gm. The density of each block calculated as follows: Density in kg/cubic m = Mass of block in kg/Mass of block in sq cm * 106
  • Three full size blocks shall be completely immersed in clean water at room temperature for 24 hours. The blocks shall then be removed from the water and allowed to drain for one minute by placing them on a 10 mm or coarser wire mesh, visible surface water being removed with a damp cloth, the saturated and surface dry blocks immediately weighed. After weighing all blocks shall be dried in a ventilated oven at 100 to 1150C for not less than 24 hours and until two successive weighing at intervals of 2 hours show an increment of loss not greater than 0.2 percent of the last previously determined mass of the specimen. The water absorption calculates as given below: Absorption, percent =(A-B)/B * 100 Where, A = wet mass of unit in kg. B = dry mass of unit in kg
  • The compression testing machine should be as per IS: 516 - 1959 and IS: 14858-2000. The load capacity, platens sizes, vertical space between platens and horizontal space between machine columns shall be as per the requirements of the specimens to be tested.
  • Specific surface of the pozzolana - in cm2 /g
  • To determine the fineness by sieving
  • Soundness of a sample is a measurement of its tendency to crack, distort, pit or disintegrate. Either of the two following tests can be used to establish soundness:
  • ‘Le Chatelier’ method uses a simple expandable ring to indicate the expansion of a sample over a set period of time
  • The autoclave method. This method tests for expansion after a certain period of time at elevated temperature in an autoclave.
  • The sample is prepared in accordance with the Indian Standard for testing cement, but in place of cement a mixture of pozzolana and cement in the ratio 0.2N: 0.8 by weight is used,
  • where, N = Specific gravity of pozzolana/ Specific gravity of cement
Initial and Final Setting Time
  • Simple tests are carried out to determine the setting times for a lime-pozzolana and lime-cement sample. Apparatus used is called the Vicat set
Lime Reactivity
  • The test for lime reactivity as given in these standards is very similar to the test for compressive strength. A series of 50mm cubes are prepared using a lime : pozzolana : sand mixture. They are allowed to cure for 8 days in an incubator and the compressive strength of the cubes is measured.
Compressive Strength
  • A similar test is carried out as for the lime reactivity given above, but the mix contains cement in place of lime. Compressive strength tests are carried out on specimens which have been incubated for 7, 28 and 90 days. A control test is also carried out using a pozzolana-free mixture. Three 50mm cubes are tested and the average figure used.
Drying Shrinkage
  • A simple test on a 250 x 10 x 10mm block to deduce the shrinkage over a 7 and 35 day period.
Reduction in Alkalinity and Silica Release
  • Only applicable to certain pozzolanas, this test helps to ascertain the effectiveness of some pozzolanas in reducing the harmful effects of alkali-aggregate reaction in concrete. It is a chemical test using reagents to determine the reduction in alkalinit
Specific Gravity
  • A simple measurement of the specific gravity of the raw pozzolana using a piece of apparatus known as the ‘Le Chatelier’ flask.