Argamassa termoeficiente com baixo impacto ambiental para reparos em edifícios históricos

Abstract

Historical buildings represent important testimonies of a people’s heritage. Having been designed with architectural strategies consistent with the climate of their time, these buildings now face challenges arising from current climate change. Therefore, it is essential to seek compatible and sustainable solutions that consider both thermal performance and historical

preservation. In this context, this study aimed to develop a thermally efficient and low- environmental-impact mortar for the restoration of historic buildings. Three industrial

residues from Ceará were collected: steelmaking slag, ceramic kiln ash, and Cariri Stone powder, and subsequently characterized in terms of their physical, chemical, and morphological properties. The mortars were produced in a 1:5 ratio (binder:aggregate), respecting the typical composition of historical mortars in the region, with the Church of Nossa Senhora do Rosário, in Aracati, serving as the case study. Cement and lime were used as binders, and the residues were incorporated into distinct mixtures, either fully replacing the conventional aggregate or partially replacing the binders (up to 25%). The mortars were analyzed for physical, mechanical, morphological, and thermal properties. In parallel, the thermal performance of the historic building was evaluated through thermal simulation using EnergyPlus. The mechanical performance of the mortars was adequate, except for the mixture containing steel slag. The void index increased with the incorporation of ceramic kiln ash and Cariri Stone powder, resulting in lower thermal conductivity in the cement-based mortars. In lime mortars, the behavior remained stable. The simulation indicated that the formulations did not modify the thermal comfort or the annual cooling energy consumption (485.04 kWh) of the historic building, maintaining indoor conditions that were slightly warm but acceptable (91% occupant satisfaction). Overall, the developed mortars proved to be compatible, ecological, and suitable for use in historic buildings.