Durability of simulated shredded rubber tire in highly alkaline environments

In applications where high strength is not of prime importance, automobile and truck tires can be recycled by shredding them and incorporating them in concrete. When the rubber is placed in the concrete, it should have minimal strength reduction and undergo minimal degradation due to the prolonged exposure to the concrete matrix. In this preliminary study, the stability of shredded rubber in concrete was simulated by exposing the shredded rubber to highly alkaline environments for up to 4 months. The degradation of rubber immersed in different chemicals was monitored by observing the changes in mass, swelling, tensile strength, and microstructure. The results show that the shredded rubber undergoes small change in a highly alkaline medium after 4 months, which suggests that the addition of rubber to concrete will not dramatically affect the durability of concrete. (C) 1997 Elsevier Science Ltd.