Mortars with wastes for thermal insulation rendering of precast concrete wall

Abstract

In a context of thermal performance and sustainable development, this paper aimed to develop rendering mortars with thermal insulating properties for the precast concrete wall. The experimental program consisted in evaluating three mix proportions with expanded polystyrene (EPS) waste and a finishing process waste of thermal insulating panels (rock wool, glass wool and vermiculite) and a standard mortar. Waste was characterized by SEM, XRD, XRF spectroscopy and helium gas pycnometry. The characterization was performed with tests in mortars (fresh and hardened state) and tests of a precast concrete wall plastered with mortar (bond strength and water permeability). In addition, thermal performance evaluation was carried out showing as a main advantage the thermal insulation of lightweight mortars with wastes compared to common mortars (thermal conductivity four times lower). The addition of waste with fibers resulted in better mechanical properties for mortars and rendering (tensile strength and bond strength).