Matrix Tailoring for Polyvinyl Alcohol (PVA) Fiber-Reinforced Ductile Cementitious Composites

The main concern for the limited practical applications of strain-hardening cementitious composite, especially in China, is the high cost of imported materials, mainly polyvinyl alcohol fibers. This study uses local ingredients to develop strain-hardening cementitious composite reinforced with non-oil-coated Chinese polyvinyl alcohol fiber. The cementitious matrix consisting of cement, fly ash, viscosity-modifying agent, and silica fume was prepared, and the matrix tailoring was performed to achieve improved mechanical performance. The prepared composites were evaluated by rheology, three-point bending, and tensile characterizations. It is found that with the given local ingredients and matrix modification, the toughness index value of 100 (I-40) according to the American Society for Testing and Materials can be achieved. Besides, the tensile results showed the improvement of 45% and 60% for first-cracking strength and peak tensile strength values, respectively. The effects of matrix modification are also analyzed statistically using the analysis of variance for the mechanical properties of the cementitious composite. The post hoc statistical analysis using the Tukey-Kramer honestly significant difference illustrated the optimum cementitious mix from the experimental data. The presented results of cost-effective strain-hardening cementitious composite are expected to promote the practical applications of strain-hardening cementitious composite in China.