Effects of Hybrid PVA–Steel Fibers on the Mechanical Performance of High-Ductility Cementitious Composites

Abstract

Producing high-ductility cementitious composites (HDCC) increased in parallel with concrete demand in China recently. However, the high cost of manufacturing cementitious composites (HDCC) persists. To reduce the cost of HDCC, steel fibers, polyvinyl alcohol (PVA), and river sand were used to produce HDCC concrete in the present study. A total fiber content of 2% was formed with five different proportions of PVA fiber and steel fiber. Within the scope of the experimental studies, mechanical (workability, compressive strength, tensile, and bending properties), and microstructural (scanning electron microscopy) tests were carried out to investigate the properties of the hybrid fiber-reinforced composites. The results showed that the fluidity of HDCC increased with increasing steel fiber substitution. The compressive strength of the mixture containing 0.5% steel fiber and 1.5% PVA fiber exhibited a better compressive strength of 31.3 MPa. The tensile performance of the mixture was improved due to the incorporation of steel fiber. The initial cracking strength was about 2.32 MPa, 25.4% higher than that of the reference group, and the ultimate tensile strength was 3.36–3.56 MPa. However, reducing the content of PVA fiber impacts the flexural rigidity of the matrix.