Evaluation of the mechanical and durability properties of eco-efficient concretes produced with porcelain polishing and scheelite wastes

摘要

The construction industry uses large-scale natural resources to production of concrete among which cement and aggregates are fundamental components. This process causes environmental impacts that are not aligned with sustainable propositions and perspectives. Likewise ceramic and mining industries generate various wastes disposed of inappropriately which can be harmful to environmental systems. Given these facts the present study aims to understand better the physical mechanical and durability of eco-efficient concrete produced with partial and hybrid substitutions of cement and sand by porcelain polishing residue (PPW) and scheelite residue (SW) respectively. For this an experimental campaign was developed divided into two stages. The first phase consisted of performing tests (consistency water absorption and porosity by immersion and compressive strength) in concretes with fixed fine aggregate contents (mixture of 81% and 19% of SW and sand respectively) and with partial replacement of Portland cement by 0 5 10 15 20 25 and 30% of PPW aiming to select the mixture with better physical and mechanical performance. Finally the second experimental phase consisted of evaluating the evolution of compressive strength and durability (capillary water absorption and chloride penetration) properties of the & nbsp;selected eco-efficient concrete. A microstructural analysis using XRD was also conducted to identify the main phases present in the concretes with wastes. The results showed that 15% is the optimum content to replace cement with PPW. A decrease in the consistency compressive strength water absorption and porosity of the concretes with this waste compared to the reference mixture was also observed 28 days. However at 90 days the mechanical behavior of the concretes was improved due to the filling effect and the pozzolanic activity of PPW. The durability properties indicated less pore connectivity and resistance to chloride migration equivalent or slightly higher than the reference concrete.& nbsp; & nbsp;(c) 2021 Elsevier Ltd. All rights reserved.