Using Eco-Friendly Recycled Powder from CDW to Prepare Strain Hardening Cementitious Composites (SHCC) and Properties Determination

Abstract

Using eco-friendly recycled brick powder (RBP) derived from waste brick to prepare strain hardening cementitious composites (SHCC) provides a new way of recycling the construction and demolition waste (CDW), and the dosage of cement in SHCC can be decreased. This paper investigated the micro-properties and mechanical properties of SHCC containing RBP by a series of experiments. The results showed that RBP had typical characteristics of supplementary cementitious material (SCM). The addition of RBP increased the SiO2 content and decreased the hydration products in cementitious materials; in this case, the mechanical properties of mortar decreased with increasing RBP replacements, and a linear relationship was observed between them. It was noticed that the adverse effect of RBP on the mechanical properties decreased with increasing PVA fiber content in mortar. For SHCC containing various RBP replacements, the ultimate load increased, and the ultimate displacement decreased with increasing curing days. When using RBP to replace cement by weight, the ultimate displacement increased with the addition of RBP. Meanwhile, there was no significant reduction in the ultimate load of SHCC. When using RBP to replace fly ash (FA) by weight, the incorporation of RBP decreased the ultimate displacement of SHCC, whereas the ultimate load was improved. For example, the ultimate load and displacement of SHCC with 54%RBP were 17.6% higher and 16.4% lower, respectively, than those of SHCC with 54% FA.