Recycled Construction and Demolition Waste as Supplementary Cementing Materials in Eco-Friendly Concrete

Abstract

Growing environmental awareness and scarcity of natural resources are forcing the world tomigrate from linear to circular economies. The possibility of partially replacing cement with ceramicbased waste from construction and demolition waste (C&DW) is a government and industry focus.The present study analyzes the effects of including finely ground complete walls of ceramic blocks(including masonry mortars) as supplementary cementing materials (SCM) on the physical, mechanical, and transport properties (water absorption and permeability) of concrete. The replacement ratioemployed was 25% by weight of cement. Studies of the hydration evolution of cement pastes supportthe described properties of concretes. The findings reveal that the ground ceramic-based waste fromC&DW stimulates hydration at all ages. Initially, this stimulation is predominantly physical (fillereffect), but in later stages, it becomes chemical (pozzolanic reaction). Based on the results obtainedin this study, it is possible to produce concrete with mechanical properties comparable to those ofconventional concrete at 28 days.