Effect of expansive agent and curing condition on the properties of low-cost polyvinyl alcohol engineered cementitious composites

At present, the traditional ECC material has the disadvantages of high cement content and high cost of PVA fiber, which seriously limits its application in engineering. In order to develop a sustainable building material for engineering, a low-cost and high toughness engineered cementitious composites (ECC) was prepared by using domestic polyvinyl alcohol (PVA) fiber. The effects of expansive agent (EA) and curing condition on the mechanical properties, shrinkage, early hydration degree and volume water loss rate of PVA-ECC were studied. The microstructure of PVA-ECC was analyzed by scanning electron microscopy (SEM). The test results show that EA can effectively improve the flexural and uniaxial tensile properties of PVA-ECC, as well as the shrinkage resistance, early hydration degree and volume water loss rate of PVA-ECC. Unexpectedly, the maximum uniaxial tensile strain of PVA-ECC material can reach 4.68%. In addition, it was found that PVA-ECC exhibited ultra-high tensile toughness when EA content was 10% under natural curing conditions. The above results verify the feasibility of domestic PVA fiber in ECC. This study can open up a new development direction for PVA-ECC in the future.