Concrete Cube Test

The Concrete Cube Test is conducted to accurately determine the compressive strength of concrete elements. Typically, cube specimens with dimensions of 150 x 150 x 150 mm, suitable are used when the largest aggregate size is 20 mm or less. In cases with larger aggregates, 100 x 100 x 100 mm cubes may be utilised. For most projects, the 150 x 150 x 150 mm cube size is standard.

During the process, the concrete is carefully poured into the molds and properly tempered to eliminate any air voids. After 24 hours, the molds are removed and the test specimens are immersed in water for curing. To ensure accurate results, the top surface of each specimen is prepared to be even and smooth by applying a layer of cement paste.

Then, the compression testing is perfomed on these specimens after specific curing periods, commonly at 7 and 28 days. However, project requirements for testing at 3, 7 and 14, or more days of curing can also be accommodated. The compressive strength is calculated using the formula:

Compressive Strength = Load at Failure / Cross-sectional Area

The load is applied gradually using a compression testing machine at a rate of 140 kg/cm² per minute until the specimen fails. The test procedures strictly adhere to IS 516 (Part 1/ Sec 1) : 2021 standards, ensuring reliable and accurate assessment of the concrete's compressive strength.