Thermomechanical characterization and thermal simulation of a new multilayer mortar and a light-weight pozzolanic concrete for building energy efficiency

Abstract

A brand-new sandwich material has been developed with a pozzolan-granular, plaster composite core and two cement mortar protective layer. The main goal of this study is to test the thermal behavior of a new sandwich material as well as the thermomechanical characteristics of pozzolanic concrete. The effects of granulomere sizes on the thermal properties of sandwich materials, as well as the volume fraction of pozzolan on the thermomechanical properties of lightweight concrete, have been studied. As a reference, mortar and concrete samples were made. The morphology and chemical composition of pozzolan granular were studied using scanning electron microscopy and X-ray fluorescence respectively. An energy building simulation of a prototype by Using TRNSYS simulator software, with variable internal and external walls composition, is performed; in order to evaluate the energy performance of sandwich material and lightweight concrete with optimum mechanical and thermal properties obtained from this work. Experimental results have shown that the incorporation of pozzolan as aggregates in the multilayer material and the concrete improves their thermal behavior. For multilayer material, it was shown that thermal conductivity varies from 0.682 W.m−1.K−1 to 0.42 W.m−1.K−1 for a sandwich sample having a granular size of pozzolan (7–20 mm) compared with reference mortar with 21.17 % mass gain. Concerning effusivity and diffusivity, of the same samples are varied from 723 to 575 J m−2.K−1.s−1/2 and from 3.51 to 2 10–7 m2.s−1 respectively. While for concrete without pozzolanic aggregate compared with a lightweight concrete sample having 100 % of volume fraction of Pozzolan, the thermal conductivity varies from 1.5 W.m−1.K−1 to 0.79 W.m−1.K−1 respectively with 31 % mass gain. Unfortunately, the mechanical performance decreases. The results of the thermal simulation have shown that sandwich material and lightweight concrete might be used in the thermal building envelope and walls. It offers significant reductions in cooling and heating energy consumption of 22 % and 14 %, respectively, as well as a significant yearly decrease in CO2 emissions of roughly 611.57 kg CO2e and 810 KgCO2e. When compared to other common wall materials, the results reveal that the new green construction materials have exceptional self-insulation properties.