Mixture Optimization on internally Cured High Strength Engineered Cementitious Composite with pre-wetted Sand-like Zeolite

摘要

In this paper, mixture optimization on internally cured high strength engineered cementitious composite (HSECC) with pre-wetted sand-like zeolite is conducted based on shrinkage and mechanical performance tests. Experimental study on the effect of the replacing ratio of the cement with the calcined zeolite on matrix compressive and bending strength was carried out first. Based on above test results, four optimized mixtures with the zeolite addition of 144, 194, 244 and 294 kg/m~(3) were obtained. Shrinkage and uniaxial tensile tests on the four high strength matrix reinforced with 2% PVA and 1% steel fibers were conducted. Through mixture optimization, strength of cement matrix with the calcined zeolite addition is further improved. The optimized replacing ratio of cement with the zeolite in the matrix is existed to obtain the highest compressive and bending strength. Shrinkage the HSECC with optimized addition of the calcined zeolite is significantly reduced. The highest reduction rate on shrinkage of the composite comparing to the reference achieves 78%. Tensile performance with optimized addition of the calcined zeolite is improved comparing with the reference mixture as well. Four optimized mixtures of HSECC are obtained with cracking and tensile strength, ultimate tensile strain and average crack width at tensile strength achieving of 4.31 - 5.48 MPa and 6.36 - 7.27 MPa, 1.01 - 1.27% and 18 - 24 μm.