Influência do teor de hidroxipropilmetilcelulose nas propriedades mecânicas e térmicas de argamassas

Abstract

The application of insulating materials in civil construction is an intelligent strategy that promotes energy efficiency by reducing energy consumption through better thermal retention in environments, making them more comfortable and saving resources. The aim is to improve thermal performance primarily through the use of techniques to maintain internal temperatures using cementitious materials with the addition of additives that acquire insulating properties. Therefore, the present study aims to observe the influence of the use of hydroxypropyl methylcellulose (HPMC) on the thermal and mechanical properties of rendering mortars. For this purpose, five concentrations of the product were analyzed (0,015%, 0,030%, 0,045%, 0,060%, 0,090%) and compared to the reference mix. To determine the properties of the fresh and hardened state of the mortars, tests were conducted for compressive strength, flexural tensile strength, flexural bond strength, water absorption by immersion, bulk density, modulus of elasticity, and water loss by evaporation. Thermal performance was determined through a simulator. The results indicate that the use of HPMC allows obtaining a lighter material with a reduction of 11,76% in weight due to the high porosity caused by the additive. This high void content contributes to thermal insulation by reducing the material's conductivity by up to 30%, while the heat flux remains fixed at approximately 49 W. The resistance to heat transfer through the plate varies according to the addition of HPMC, with higher incorporation of the additive presenting 32,6% more thermal resistance than the reference mix.