Experimental investigation of effects of multi-fissures on brittleness of ordinary Portland cement concrete and rubberized concrete

Abstract

The Brittleness index of concrete is related to both confining pressure, ambient temperature, its components and internal defects, especially all types of fissures. In the paper, the experiments were conducted to investigate the relationships between brittleness index and concrete composition and flaws under uniaxial compression through the brittleness index of OPC (ordinary Portland cement concrete) and RC (rubberized concrete) containing multi-fissures. The results show that the relationship of brittleness index and concrete composition is positive to brittleness index change of OPC and RC containing multi-fissures. The brittle index of OPC is 18.3% higher than that of RC which replaced 10% sand by rubber power. As for OPC containing two fissures, the brittleness index is lower 48.8% than that of intact specimens and the specimens containing 45°angle has the lowest brittle index among counterpart of RC. As for RC with parallel and non-parallel fissures, the brittleness of the latter is 18.8% smaller than that of the former. The brittle index of the RC with non-parallel fissures declines the most and largest damage. Finally, OPC and RC containing fissures contribute to their toughness and ductility if permissible. The reliability of the new index of brittleness can nicely enrich and improve the existing evaluation methods of concrete brittleness.