11.1 An Introduction to Rubber Concrete

Rubber concrete represents a generic name for a mixture of conventional Portland cement concrete with crumb rubber, which is a granular material produced by shredding and comminuting used automobile tyres. In the USA, 250 millions of used automobile tyres are generated each year and there are about 2 to 3 billion used tyres already existing in landfills. The question of how to improve the properties of concretes in addition to how to simultaneously find new ways to reuse those used tyres, has been the main driving force for exploring new ideas, and rubber concrete has evolved from one of them.

There are about 40 research papers available in the literature on this subject worldwide, most of which involve mainly analytical and laboratory work.

The early research on rubber concrete begun at late 1980s and early 1990s. One of the early studies was carried out by Eldin and Senouci [1] to explore the effect of rubber chips and crumb rubber on the compressive and tensile (flexural) strengths of concrete mixes, and the use of rubber concrete in light-duty concrete pavements was suggested [2, 3]. In the same year, Biel and Lee experimented with a special (magnesium oxychloride) cement to enhance the bonding between rubber particles and cement [4]. Later, rubber concretes are shown to achieve higher toughnesses [5, 6], and the models of composite mechanics were provided [7, 8]. The issue of freeze-thaw durability of rubber concrete was first investigated by Savas and...