Influence of Rubber Powder on the Mechanical Behavior of Engineered Cementitious Composites

Engineered cementitious composite (ECC) is a kind of composite reinforced with moderate fiber volume fraction, typically 2% by volume. Of special interest is the capability of ECC material to deform to high tensile strains, commonly over 3%, while maintaining very tight crack width. In this study the rubber powder is used in ECC to partially replace fine silica sand, thus enhancing the greenness of ECC. Two particle sizes of rubber powder (450 μm and 200 μm on average) are used in this research. Furthermore, there are three different dosages (0, 10%, 15% by volume replacing silica sand) for each rubber powder size. The influence of rubber powder on the ECC mechanical properties is revealed via flexural deformation, crack width and compressive strength. In this paper, it is found that the addition of rubber powder into ECC decreases its first cracking strength with the trend of enhancing deformation capacity. With the increasing volume of rubber powder, the crack width gets lower. The deformation capacity gets enhanced and compressive strength decreases when the dosage of rubber powder is 15%. The study results prove that it feasible to produce ECC by replacing silica sand partially with rubber powder, thus greatly promoting the greenness of ECC.