Compressive Strength of concrete is defined as the Characteristic strength of 150mm size concrete cubes 28 days. Compressive strength of Concrete and its importance:- As we all know that concrete is a mixture of sand, cement, and aggregate.
Compressive Strength of Concrete Cube = Maximum load/Area of the cube Example Calculation. Assume that the compression load is 375 KN 1 Kg = 9.81 N Cross Sectional Area – 15 x 15 = 225 Sqcm. Compressive Strength = 375 x 1000/225 = 1666/9.81 = 169.82 Kg/Sqcm. Compressive strength of concrete at days
Early-age strength evaluation refers to testing the strength gained between day 1 and day 28 after concrete placement. During this period, a lot is happening with your concrete. Testing concrete during this early time is extremely important to ensure the integrity of your structure and avoid any structural failures down in the future.
Average compressive strength of the concrete cube = ………….N/ mm 2 at 7 days
Compressive Strength of Concrete IS 456 Interpretation of Test Results of Sample specified Grade Mean of the Group of 4 Non-Overlapping Consecutive Test Results In N/mm2 Individual Test Results In N/mm2 1 2 3 M 20 > fck 0.825 X established SD > fck -3 N/mm2 or above
Compressive strength as per American Codes. In case of American codes, compression strength is defined in terms of cylinder strength fc’. Here compressive strength of concrete at 28 days curing is obtained from a standard cylindrical specimen 150mm diameter and 300mm high loaded longitudinally to failure under uniaxial compression loading.
It is the most important factor for gaining the strength of concrete. The lower w/c ratio leads the higher strength of concrete. Generally, the water/cement ratio of 0.45 to 0.60 is used. Too much water leads to segregation and voids in concrete. Water/Cement ratio is inversely proportional to the strength of concrete.
Concrete with a PSI rating of 6000 or more is considered high-strength concrete. It is typically found in nuclear power plants and other areas where radiation contamination is possible. High strength concrete has a lower water-cement ratio, giving it additional durability and strength.