SOHAM CONSULTING SERVICES

Concrete Testing

Quality tests on concrete are performed as a part of quality control of concrete structures. Different quality tests on concrete such as compressive strength tests, slump tests, permeability tests etc, are used to assure the quality of the concrete that is supplied for a given specification. These quality tests on concrete give an idea about the properties of concrete such as strength, durability, air content, permeability etc. 

Physical Tests & Parameters 

Test on Fresh Concrete

Slump Cone Test on fresh concrete

The concrete slump test measures the consistency of fresh concrete before it sets. It is performed to check the workability of freshly made concrete, and therefore the ease with which concrete flows. It can also be used as an indicator of an improperly mixed batch.

The slumped concrete takes various shapes and according to the profile of slumped concrete, the slump is termed as true slump, shear slump or collapse slump. If a shear or collapse slump is achieved, a fresh sample should be taken and the test repeated.

Compaction Factor Test

The compaction factor test is carried out to measure the degree of workability of fresh concrete with regard to the internal energy required for compacting concrete thoroughly. The compacting factor test is used to find out the low workability of concrete.

Setting time of fresh concrete

Initial setting time: The time elapsed after initial contact of cement and water, till the mortar acquires a penetration resistance of 3.5 MPa.

Final Setting time: The time elapsed after the initial contact of cement and water, till the mortar acquires a penetration resistance of 27.6 MPa.

Test on Hardened Concrete

Compressive Strength of Cube & Core

The cube test is most commonly used for determining the value of compressive strength that can be used to assess whether the batch that the concrete cube represents, meets the required compressive strength or not. A cube of concrete in the cast is cured for the appropriate time and is then compressed between two parallel faces.

Flexural Strength of Beam

Flexural Strength is the ability of a beam or slab to resist failure in bending. It is measured by loading un-reinforced 600x100×100 mm and 700x150x150 mm concrete beams.

Density of hardened concrete of cube & cylinder

This test method covers determination of the density of freshly mixed concrete and gives formulas for calculating the unit weight, yield or relative yield, cement content, and air content of the concrete. Yield is defined as the volume of concrete produced from a mixture of known quantities of the component materials.

Concrete Core Extraction and Testing

This test is used to determine the compressive strength of a concrete core, which has usually been extracted from an existing structure. The value of compressive strength can then be used in conjunction with other measured properties to assess the condition of the concrete. Using a masonry saw, the core is first trimmed to the correct test length, which varies upon the standard being adopted. Following trimming, the core will have its ends either ground perfectly flat, or be capped in a material to produce a smooth bearing surface. After the prescribed curing has taken place, the specimen is then crushed to failure noting the maximum load achieved. From the values of load and dimensions, the compressive strength of the core can be calculated. 

Permeability Test for concrete and cement mortar

Permeability of cement mortar or concrete is of particular significance in structures which are intended to retain water or which come into contact with water. Besides functional considerations, permeability is also intimately related to the durability of concrete, specially its resistance, against progressive deterioration under exposure to severe climate, and leaching due to prolonged seepage of water, particularly when it contains aggressive gases or minerals in solution. The determination of the permeability characteristics of mortar and concrete considerable importance. 

Splitting Tensile Strength of cube & Cylinder

Tensile strength is one of the basic and important properties of concrete. Knowledge of its value is required for the design of concrete structural elements. Its value is also used in the design of prestressed concrete structures, liquid retaining structure, roadways and runway slabs. 

Depth of Water Penetration under Pressure

The method determines the depth of penetration of water under pressure in hardened concrete that has been water cured. Water is applied under pressure to the surface of hardened concrete. The specimen shall then be split and the depth of penetration of the water front is recorded and measured.