Fundamental Performance of UHDMC with PVA Fibers

This Chapter develops ultra-high ductility magnesium phosphate cement-based composites (UHDMC) by adding PVA fibers to magnesium phosphate cement (MPC)-based composites. This chapter introduces the effects of fly ash (FA) content, polyvinyl alcohol (PVA) fiber volume fraction (Vf), sand to binder mass ratio (S/B), and water to solid mass ratio (W/S) on the workability, compressive strength, tensile properties, and flexural properties of the UHDMC. The optical microscope test is conducted to examine the microstructure of PVA fibers and their bonding with the matrix. Overall, when the FA content is 20% or 30%, the UHDMC can obtain relatively high strength and strain capacity without significant workability loss; the UHDMC can obtain relatively high workability, strength, and strain capacity when the Vf is 1.6% or 1.8%; when the S/B is 0 or 0.2, the workability, strength, and strain capacity of the UHDMC are the highest; when the W/S is 0.13 or 0.16, the UHDMC can obtain relatively high strength and strain capacity while maintaining good workability. The microstructure analysis shows that PVA fibers are well embedded in the matrix and can effectively bear stress and limit the initiation and propagation of cracks, resulting in multi-cracking.