Factorial design used to model the compressive strength of mortars containing recycled rubber

This paper presents results from an investigation on the potential use of waste vulcanized rubber scrap (WRS) particles as aggregate in construction mortars. The investigation was carried out using a 3² factorial design of experiments and the response surface methodology. Mortar mixtures were prepared using WRS as fine aggregate (10, 20 and 30 vol.%) with water/cement ratios of 0.52, 0.55 and 0.60. Fresh mortar consistency index and hardened mortar 28-day compressive strength were evaluated. The influence of the WRS content on the physical and mechanical properties was established, and the suitability of WRS use in a mortar application was demonstrated.