Experimental investigation on the impact resistance of rubber self-compacting concrete

Stiffness degradation and micro-cracks are commonly observed in the self-compacting concrete subjected to longterm vibration and impact loading. Adding rubber particles to the concrete is a universal approach to improve impact resistance. Exploiting the dynamic mechanical properties of the rubber self-compacting concrete under impact loading is of great significance. Herein, a comprehensive investigation of rubber self-compacting concrete under impact loading was carried out using a split Hopkinson pressure bar. The influence of rubber replacement rate, rubber particle size, and strain rate on impact resistance was considered. 108 rubber self-compacting concrete specimens along with 36 ordinary self-compacting concrete ones were designed. As a result, the dynamic stress-strain relationship of rubber self-compacting concrete was proposed. The results show that rubber self-compacting concrete's dynamic peak strain and peak stress were higher than ordinary self-compacting concrete with similar static compressive strength. The dynamic compressive strength and DIF-a and DIF-e of rubber self-compacting concrete can be increased with strain rate. The sensitivity of growth rates of DIF-a and DIF-e to strain rate decreases with the strain rate. DIF-a and DIF-e showed a positive linear correlation with rubber content. The increase of rubber content reduces the dynamic compressive strength of rubber self compacting concrete. Compared with other sizes, the dynamic compressive strength and DIF-a and DIF-e of 12 mesh (1 2 mm) rubber particles are generally higher.

Automated summary

The study found that adding rubber particles to concrete can improve its impact resistance but may decrease its dynamic compressive strength. Additionally, the size of rubber particles and the strain rate of concrete can also affect its impact resistance.