Fundamental Performance of UHDMC with Hybrid Fibers

This chapter investigated the performance of ultra-high ductility magnesium phosphate cement-based composites (UHDMC) reinforced by multiple types of fibres. Compared with the use of a single type of fibre, the mixed use of multiple fibres can significantly improve both strength and toughness of the cementitious composites, which is referred to as the hybrid effect. Considering polyvinyl alcohol (PVA) fiber, micro steel (MS) fiber and polypropylene (PP) fiber are three of the most widely used fibers for UHDMC, this chapter introduced the hybrid effect of each two of these three fibers. The hybrid effects on workability, compressive strength, and flexural strength were investigated. In addition, the cracking propagation of UHDMC was observed and associated with the deflection by modelling. To further understand the mechanism of the hybrid effect, this chapter also provides the microstructural analysis of the UHDMC. The findings in this chapter indicated that the mixed use of hybrid fibers can effectively improve both strength and toughness of the UHDMC, providing the base for the design of high-performance UHDMC.