Enhancement of Portland cement concrete with tire rubber particles

Over the last years significant emphasis is being placed on the use of recycled products in highway and construction materials. Today, more than 200 million passenger and track tires are being discarded every year. With the continuous restrictions on the acceptance of this material in landfills and the increasing environmental and safety concerns, there is a significant need for identifying new uses and applications for tire rubber. Rubber is being recycled to a limited degree for producing new tires. In addition, tires are being used as alternative fuel in kilns due to their high Btu content. In infrastructure constriction crumb rubber, produced from waste automobile tires, is being used extensively and successfully with asphalt mixtures. With these materials, rubber is being blended with binders, ''wet process'', for enhancing their reological properties, or used as an aggregate replacement, ''dry process.'' In Portland cement concrete, rubber from granulated tires may be used as an elastic fine or coarse aggregate modifying the brittle failure of concrete and increasing thus, its ability to absorb higher amount of energy before failure. This paper describes the results of an experimental study conducted for evaluating the effects of incorporating granulated rubber into Portland cement concrete. In this investigation, the effects of different rubber contents on Portland cement concrete properties were examined through destructive and nondestructive techniques. A comparison with conventional Portland cement concrete indicated that the use of rubber particles significantly improves the characteristics of concrete. Further analysis are currently being conducted for evaluating the long term performance of the rubber filled concrete.