Comparative study of three types of fine recycled aggregates from construction and demolition waste (CDW), and their use in masonry mortar fabrication

Abstract

This research aims to study feasibility of incorporation of fine fraction of recycled aggregates coming from construction and demolition waste in cement-based masonry mortar fabrication. Initially, three types of recycled aggregates: concrete, mixed and ceramic recycled aggregates, were characterized in terms of physical, mechanical and chemical properties. There were used 1:3 and 1:4 cement-to-aggregate proportions and replacement percentages of 50%, 75% and 100% respectfully for three types of studied recycled aggregates. Physical characterization of recycled aggregates shows a continuous size distribution curve, lower density and higher absorption, what makes the usage of additive necessary to obtain appropriate consistency. Main crystalline phases shown in the X-ray diffraction analysis were: calcite, quartz and gypsum. According to the results of the dosages study, recycled mortars present poorer behaviour than mortars fabricated using natural stand, however, complying with the limits established by the standards and manufacturers. Therefore, the results of this study suggest the possibility to replace 100% of natural sand with analyzed recycled aggregates. © 2016 Elsevier Ltd.