Tensile performance of polyvinyl alcohol–steel hybrid fiber reinforced cementitious composite with impact of water to binder ratio

Abstract

The tensile performance of polyvinyl alcohol (PVA)–steel hybrid fiber reinforced engineered cementitious composite special focus on impacts of steel fiber content and matrix strength has been investigated and reported in this paper. Four matrix types with water to binder ratio of 0.25, 0.35 0.45 and 0.55 and three additional steel fiber contents in the composite with PVA fiber content of 1.7% in volume were used in the test program. The experimental results show that cracking and tensile strength of the composites is increased with the addition of steel fiber. This enhancement becomes more and more pronounced with decreasing of water to binder ratio of the composites. The additional steel fiber can also increase the tensile strain capacity of the composites, especially for high strength composite that normally has relatively lower tensile strain capacity than that of low strength composite. However, moderate amount of steel fibers is needed in order to obtain a positive response on the ultimate tensile strain of the composites. The optimal steel fiber content existed for this kind of composite with consideration both of strength and strain improvement. The highest to lowest tensile strength and strain in each matrix group at 28 days are 4.58–3.88 MPa (0.68–1.84%), 4.02–3.70 MPa (0.82–2.39%), 3.50–3.32 MPa (1.14–2.58%), and 2.76–2.25 MPa (1.63–3.31%).