Effect of Rise in Temperature (250°C) on the Physico-Mechanical Properties of Rubber Mortars

The recovery and use of waste in the field of civil engineering, particularly in construction materials, is one of the most prominent solutions for preserving the environment. In order to evaluate the results obtained, it is necessary to study the evolution of the properties of these new materials in the different environments where they can live or be exposed, and why not develop an effective method of treatment of such materials for the possibility of their use even in the field of precast concrete. The objective of this work is to study the effect of the increase in temperature as a living environment or as a treatment on the physico-mechanical properties of a crumbled mortar, a potential source of many environmental and economic problems. Hence the screening and the possibility of using these new mortars with sufficient physico-mechanical properties for masonry and why not for prefabrication. The formulation of the mixtures based on the substitution of dune sand by crumb rubber, at different weight contents 10, 20 and 30%. Consequently, prismatic specimens (4x4x16) cm³ subjected to the temperature (250°C), with a speed of 2°C/min followed by a one-hour plateau at the target temperature then cooling to the ambient temperature. The results obtained show that the maximum mass loss is 5% for 30% substitution and that for 10% substitution the absorption by total immersion decreased by more than two thirds and the porosity accessible to water decreased by more than half. The compressive strength increases by 8.9% for 10% substitution and the minimum decrease in tensile strength by bending is at the same substitution of an order of 26.9%. Using the analysis of variance, the influence of the substitution of dune sand by rubber crumbs and of the rise in temperature to 250°C on the behavior of the mortar acquired. Patterns developed by response surface methodology were significant for all p-value substitutions <5%. The results of the numerical optimization showed that the best mixture could obtained by replacing 30% of dune sand with rubber crumb and subjecting the hardened mortar obtained from this mixture to the temperature of 135°C.