Evaluation of mechanical and microstructure properties of engineered cementitious composites made of zeolite

Abstract

Engineered cementitious composite (ECC) is a type of cementitious product with high tensile strength and ductility. It exhibits high strain and multiple cracking behavior instead of deep and wide cracks due to tensile and bending loads. In this study, the efficiency, mechanical properties of different ECC mixtures containing different contents of zeolite were investigated. The zeolite to cement ratios of 1.2, 1.6, 2, and 2.4 were considered as corresponding zeolite replacement ratios. Results showed that the compressive strength of ECC mixtures attained 35 MPa at 28 days except for the mixture with Z/C ratio of 2.4, which is higher than that of the nominal compressive strength for normal concrete (30 MPa). Higher ductility was observed in mixtures with high contents of zeolite (Z/C of 2 and 2.4). It was found that despite lower strength and elastic modulus, replacement of higher zeolite showed significantly higher performance in post-crack hardening strain behavior ECC mixtures. The microstructure studies confirmed that the addition of zeolite resulted in having a rough fiber surfaces and the end of fibers were delaminated cut off which led to tolerating higher frictional strain.