Concrete Laboratory

Name Description Instruments/Softwares
MAGNETIC STIRRER MAGNETIC STIRRER is a laboratory device that employs a rotating magnetic field to cause a stir bar (or flea) immersed in a liquid to spin very quickly, thus stirring it.
Automatic Triaxial Testing System The system is controlled by the user's PC running MS Windows® and GDSLAB software integrated with Aimil electronics. The operator chooses the type of test from a test menu (eg. multi-stage, stress path etc) and then enters the test parameters (of cell pressure, back pressure, testing rate and so on) and test termination conditions. The test then proceeds automatically with all test data being saved to a file. On-line graphics are presented with up to three graphs displayed together with a block of current live test data. The computer directly controls the cell pressure, back pressure and testing rate.
Consolidation Apparatus Consolidation is reduction of volume of soil due to expulsion of water from its pore space caused by sustained loading. This phenomenon is time dependent. The one dimensional consolidation test performed on an undisturbed sample of clay is useful for understanding the history of the soil deposit. The test results can be used for calculating the settlement of structures built on clayey soil.
California Bearing Ratio Test The California Bearing Ratio test, is an empirical test developed in California, USA for determining the Relative Bearing Ratio and expansion characteristics under known surcharge weight of base, sub-base and sub grade soils for the design of roads, pavements and runways. The CSR test is used extensively in selection of materials and control of subgrades. The test can be performed in the laboratory on prepared samples or in-situ on location. It is important to appreciate that this test, being of an empirical in nature, is valid only for the application for which it was developed i.e., the design of highway base thickness.
Liquid Limit Casagrande The liquid limit defined as the moisture content at which the soil passes from plastic state to liquid state, is very helpful for the classification of the potential properties of the soil material. The liquid limit gives a measure of the shearing resistance which a soil has, when mixed with water. The liquid limit of soil can be determined by Casagrande Method or Cone Penetrometer Method.
Shrinkage Limit The Shrinkage Limit of a soil is defined as the moisture content after which any further reduction of moisture does not cause volume reduction. The shrinkage of clayey soil can be very significant. A fully saturated soil specimen is allowed to dry in free air and its volume is measured repeatedly by immersing in a mercury bath. From the data obtained from this test, Shrinkage Limit, Shrinkage Ratio, Shrinkage Index and Volumetric Shrinkage can be calculated. The choice of puddle-clay material is often governed by the results obtained from this test.
Pycnometer Specific Gravity is the ratio of the weight of a given volume of a material in air at a standard temperature to the weight in air of an equal volume of distilled water at the same stated temperature. The equipment mentioned below can be used to test a wide range of materials from clay to sand and gravel, smaller than 10 mm.
Compaction Test Apparatus Soil compaction is a fundamental requirement for the construction of earth fill for dams, reservoirs, canal embankments, highways, railways and runways. The relationship between soil moisture content and compacted dry density is very useful for deciding construction specifications and quality control of compacted earth fill. While designing a soil retaining structure, the strength and deformation behavior of soil is evaluated by testing soil specimen compacted to the density as would be achieved during construction. The construction quality control is essentially to check the density of compacted soil achieved in the field, thereby checking its strength.
Field Density Test of Soil by Core cutter method In this method, a cylindrical core cutter with a dolly of known dimensions as shown in fig. is used. A dolly is placed over the cutter to prevent damage to the edges of the cutter. Cylinder is embedded into the ground for its full height and is taken out. The surplus soil at both ends is trimmed and the weight of the cylinder is found out. From the known dimension of the cutter, volume and the moisture content of the soil is determined.
WEIGHING BALANCE WEIGHING BALANCE (0.1 gm) is an instrument which is used to determine the weight or mass of an object. Available in a wide range of sizes with multiple weighing capacities they are essential tools in laboratories for measuring.
Sand Pouring Cylinder Apparatus This is used for the in-place determination of the dry density of natural or compact soil containing stones, fine, medium grained soils for layer exceeding 15 cm but not exceeding 25cm thickness. It may also be used for measuring the density of base materials. density of base materials.
Laboratory Permeability Apparatus Permeability is a property of soil which permits flow of water through its interconnecting voids. Permeability is an important engineering property which governs the rate of settlement of saturated compressible soil layers and the rate of flow of aquifer. Coefficient of permeability can be computed from effective diameter of particles, porosity, and specific surface and from consolidation test results. Specimen used in a Permeameter is small, time taken is less and results obtained are accurate. There are two types of Permeameter, namely Constant Head Permeameter and Falling Head Permeameter.
Unconfined Compression Tester, Proving Ring Type Determination of soil shear strength is essential for designing the foundation of structures, soil and soil retaining structures, soil slopes, etc., Shear strength of soil depends on various factors and insitu soil conditions. It is well known that the engineering behavior of soil depends on the effective stress and not the total stress. The effective stress can be calculated by measuring the total stress and subtracting the pore water pressure from it.
De-Aired Water Apparatus The equipment has been designed specifically to meet the demand for de-aired water for use with Soil Testing Apparatus for reduction of time and labor to consolidate soil samples. For simultaneous flushing of many hydraulic Piezometer lines in dams and earth works to considerably reduce labor and disturbance at the top ends. It is particularly important that only de-aired water is used in the Pore Pressure measurement system. Any dissolved air in the water leads to error in measurement of Pore Pressure, particularly at low pressure.
EQUIPMENTS Different equipment’s used in Geotechnical Laboratory experiments. Shovels, Brushes, Spatula, Scoop, Spade, tamping Rod, Digging equipment, e.t.c.