Study of the Influences of Recycled Concrete Aggregate and Waste Glass Sand on the Mechanical Properties of Concrete

Abstract

Concrete is the most commonly used building material in the construction material market. However, producing concrete consumes many natural resources such as sand and crushed stone. Besides, Macau is renovating the old urban zone. Therefore, many construction and demolition waste (C&D waste) are generated. To solve the problems, substituting the natural aggregate with recycled concrete aggregate (RCA) and waste glass sand (WGS) could be a possible method. However, there are limited studies on the combined effect of WGS and RCA on the mechanical properties of concrete. To fill the knowledge gap, the slump cone test, splitting tensile strength test, and cube strength test are performed on the concrete with different RCA and WGS replacement ratios. The experimental results indicate that proper replacement of RCA and WGS slightly affects the mechanical properties of concrete except splitting tensile strength. Oppositely, the incorporation of WGS significantly improves the workability of concrete. Overall speaking, replacing up to 30% crushed stone with RCA and up to 20% sand with WGS will not significantly affect the mechanical properties of concrete.