Preparation and Performance of Sprayable UHDMC

This chapter aimed to develop a sprayable ultra-high ductility magnesium phosphate cement-based composite (UHDMC) and explored the effects of starch ether content, water–solid ratio, powder-binder ratio (P/B), borax content (B/M), fly ash (FA) substitution and polyvinyl alcohol (PVA) fibers volume content on the shootability, rheological and mechanical properties of magnesium phosphate cement-based materials. The correlation between shootability factors (build-up thickness and rebound rate) and rheological parameters (yield stress and plastic viscosity) was established, and the optimum mixture proportion suitable for the sprayed UHDMC was selected and then analyzed by the mechanical properties and pore structure between the cast and sprayed specimens. At the same time, the relationship between pore structure parameters and mechanical properties was established. The results in this chapter will offer valuable theoretical basis and specific guidance for the future application of sprayable UHDMC in engineering projects.