Thermal conductivity of cement composites containing rubber waste particles: Experimental study and modelling

In this paper an investigation of the thermal conductivity of a lightweight construction material containing rubber waste particles, is presented. Measurements were carried out in a dry state using a transient plane source (TPS) technique. To determine the effect of the rubber particles ratio on the thermal conductivity of a cement composite, 10%, 20%, 30%, 40% and 50% rubber particle ratios by volume as replacement to cement, were used. The experimental investigation revealed that the addition of rubber particles reduces the material unit weight, furthermore, thermal conductivity of the composite has been improved. The thermal insulating effect of rubber particles is most attractive and indicates a high and promising potential for development. Based on the self consistent method and assuming that the tri-phase composite consists of air, rubber particles and cement paste, thermal conductivity of the composite has been predicted as a function of the dry unit weight and formulations, using auto-coherent homogenisation model. The model requires the knowledge of rubber particles conductivity, which was experimentally measured using Horai and Simmons technique. A modelling application reveals good correspondence with the experimental results.