Tensile and compressive properties and crack characteristics of rice husk ash and crumb rubber particles modified engineered cementitious composites

Rice husk ash is the primary supplementary cementitious material, with rubber particles injected as artificial flaws. Rice husk ash and crumb rubbers engineered cementitious composites (CR-RHA/ECC) are low carbon, ecologically friendly cementitious composites with good ductility. The effects of rubber content (0, 10%, 20%, 30%) on the ductility and cracking characteristics of CR-RHA/ECC at each curing ages (7 days and 28 days) were explored employing macroscopic mechanical properties and microscopic investigations. The results show that: With the increase of age, there is a great difference in the ductility of CR-RHA/ECC. The replacement of 10% river sand by CR weakens the ductility of CR-RHA/ECC at 7 days by 54% and increases the ductility of CR-RHA/ECC at 28 days by 67%. With the increase of age (28 days), When CR replaces 30% river sand, the ductility of CR-RHA/ECC can reach 6%, and the tensile fracture width of CR-RHA/ECC decreases by 52.79% compared with that of CR-RHA/ECC without CR replacement.