Influence of proportion and particle size gradation of rubber from end-of-life tires on mechanical, thermal and acoustic properties of plaster–rubber mortars

This work presents the main experimental results obtained from the study of plaster test pieces and boards with addition of various volumetric rubber fractions from mechanical grinding of end-of-life tires (ELTs), in three different particle size gradations. It includes a description of the materials employed, and their proportions. The physical and mechanical properties, as well as the thermal conductivity and acoustic insulation properties are analyzed. Experimental results obtained for specimens with addition of recycled rubber are compared with similar ones, carried out on specimens of plaster of identical features without any addition, evaluating the influence of the particle size and mixture proportions. An improvement in thermal and acoustic performance has been obtained as well as a reduction in density, and as a result, some constructive applications for paving and slabs in rehabilitation works are proposed.

► Gypsum plaster with different sizes and volumetric fractions of rubber has been studied. ► Density decreases, but mechanical properties are also worse. ► Thermal insulation capacity improves, and this influences on the roughness appearance of the material. ► Acoustic insulation improves due to the rubber capacity to absorb vibrations. ► Best results are obtained with smaller size particles and additions of 30–40% by weight.