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Showing posts from May, 2018

How compressive strength of a concrete is determined?

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To determine the compressive strength of concrete, 6 concrete samples are prepared using cube mould. Freshly prepared concrete is poured into 6 cube moulds and are kept for curing for 7 & 28 days. The preferred size of concrete cube used in concrete testing is 150mm x 150mm x 150mm. On 7th day, 3 concrete samples are extracted from their respective cube moulds and compression test is performed using compression machine. Similar process is repeated on 28th day with remaing 3 concrete cubes.  When the force is applied on the concrete cube specimens, concrete starts to chip off and finally the specimen cracks. The force at which the specimen fails is noted and compressive strength of concrete cube is calculated. I.e, if the specimen cracks at 500kN force and size of specimen is 150 X 150 x 150 mm, the strength of cube will be (500 x 1000) / (150 x 150) N/sq. mm Finally, the mean of all 6 concrete cube specimens, is used as the compressive strength of concrete. Note: Onl

Flexural Test on Concrete Beam Mould, procedure and application

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To evaluate the tensile strength of concrete, a flexural test is performed on concrete beam. This test checks the ability of unreinforced concrete beam to withstand failure in bending. The flexural test on concrete can be conducted using 3-point load test. What are the Applications of Flexural Test on Concrete? Flexure test is an essential requirement for concrete mix design, it is employed in testing concrete for slab and pavement construction. In some countries, it is an essential requirement for concrete mix design. Procedure of Flexural Test on Concrete Take out the specimen from curing tank and place on the loading points of flexure testing machine. Center the loading system in relation to the applied force and bring the block applying force in contact with the specimen surface at the loading points. Start applying loads between 2 to 5 percent of the computed ultimate load. Apply load on to the specimen continuously without shock till the point of failure a