Utilization of Recycled Rubber in Concrete Mix Design

Camille Issa, born 1959, received his Ph D in Civil Engineering from Virginia Tech, USA in 1985. He joined Mississippi State University as Assistant Professor and was promoted to an Associate Professor in 1990. In 1993 he joined the Lebanese American University. His main area of research is Concrete.

There is no doubt that the increasing piles of used tires create environmental concerns. As waste continues to accumulate and availability and capacity of landfill spaces diminish, agencies are increasing application and use of recycled materials such as crumb rubber from tires in construction. The basic building materials in concrete construction are primarily aggregate and cement. The educated use of recycled materials can result in reduced cost potentials and may enhance performance; however, not all recycled materials are well suited for concrete construction applications. The two main reasons for not utilizing a reclaimed material are 1) addition of material is a detriment to performance, and 2) excessive cost. In this study, the performance of recycled materials crumb rubber as valuable substitute for fine aggregates ranging from 0% to 100% in replacement of crushed sand in concrete mixes is investigated. An acceptable compressive strength was obtained with up to 25% by volume replacement of fine aggregates with crumb rubber.