Hydraulic binder obtained from recycled cement and sand powder

Abstract

Currently, we have sought to obtain eco-efficient concretes through the recycling of concrete residues. Literature studies have shown that pulp heating can remove water from hydration and that quartz sand can act as supplementary cementitious material when appropriate granulometry. However, there are virtually no reports of reuse of these materials as alternative binders. This work evaluates the phases present in cementitious compounds made with binder obtained from the thermomechanical treatment of slurries with 15% quartz sand powder (RCQ) and without substitution (RC) with a specific surface area of 37.4 m²/g. Thermogravimetric analyzes were performed with the analysis of stripped gases, X - ray diffraction and scanning electron microscopy with phase identification. The obtained data show that the RC paste has a predominant microstructure of ettringite whereas in the RCQ paste the presence of calcium hydroxide and hydrated calcium silicate predominates.