Analysis of the Mechanical and Thermal Behaviour of Mortars Manufactured with Combined Use of Different Waste Products

Abstract

Abstract The present study analyses the incorporation of wastes into mortars, and the mechanical and physical response in mortars to the incorporation of these materials. Dosing must be such as to ensure that the test samples present a nominal degree of resistance of G-30. Recycled aggregates (RA) were obtained from the waste area of the prefabricated pieces production plant of Industrial y Comercial Burzio, Temuco, Chile, while biomass ash (BM) and crumb rubber (CR) were supplied by companies interested in the treatment and recycling of their waste. The matrix for the distribution of the replacement percentages was drafted using Taguchi statistical design, replacing natural aggregates with RA in proportions of 25% and 50%; CR was used to replace fine aggregates in proportions of 10% and 20%, and BM in proportions of 10%, 15% and 20%. Use of the study materials showed that with 10% of R, the mechanical properties were reduced; and that as the percentage of CR increased, the thermal conductivity diminished. The substitution of BM in a proportion of 10% increased the compression resistance and diminished conductivity by 20%. In the case of RA, the mechanical resistance was not diminished considerably compared to the control test samples, while the thermal conductivity diminished as the percentages of replacement material increased. The results showed that series S1 (0% RA, 0% R, 10% BM) and S2 (50% RA, 0% R, 15% BM) provided a compression resistance greater than 30 MPa, precisely the series which include no CR in the dosing. This result suggests that superficial pre-treatment of crumb rubber must be included in future experiments.