Compression behaviour of self-compacting concrete under high strain rate loadings at different ages

Self-compacting concrete (SCC) is widely used in reinforced concrete (RC) buildings due to its ability to consolidate by weight and its lack of requirement for external vibration. RC buildings can be subjected to high strain rate loadings during the early days of construction or in their service life. Thus, it is critical to understand the behaviour of concrete under high strain rate loadings at different ages. Previous research shows that minimal studies have focused on the early-age behaviour of concrete under a high strain rate. This study tries to fill this knowledge gap. It focuses on the behaviour of M40 grade SCC under three levels of strain rate loading at the age of one, three, seven, 14 and 28 days. The Split-Hopkinson Pressure Bar (SHPB) setup is used to test the SCC specimens with a diameter of 100 mm and thickness of 50 mm under high strain rates. Forty-five specimens were tested at strain rates ranging from 30 s(-1) to 110 s(-1) at the age of one to 28 days. The compressive strength, peak strain and elastic modulus results from the SHPB experiment are compared with the quasi-static test results of SCC specimens. The dynamic increase factor (DIF) of the SCC specimens from the SHPB experiment is compared with the CEB - fib code model. The results indicate that the DIF reduces as the concrete's strength and age increase.