John O.Sobanjo, Kamal S. Tawfiq, Richard Twumasi-Boakye, Sylvester Inkoom, Sheldon Gibbs
Florida Department of Transportation
Admixtures, Air content, cement, grain size, Ground tires, paving coarse aggregates, Tires, Water cement ratio
This research was done to investigate if the problems associated with flexibility and temperature sensitivity (expansion and contraction) in roadway concrete pavements can be addressed by replacing some of the fine or coarse aggregate component with crumb rubber, specifically, Ground Tire Rubber (GTR). The research also intended to find out the general effects of adding the GTR to the conventional pavement concrete, in terms of the mechanical properties and workability, requiring several laboratory tests to be conducted as part of the study. Finally, the research was required to evaluate the practical implementation at a ready mix plant, of the proposed use of GTR as a component in the concrete. It was found from the study that the modulus of elasticity of concrete is reduced when GTR is used in concrete, thus the pavement concrete becomes more flexible. Based on the results of the tests for the coefficient of thermal expansion (CTE), it was not conclusive from this study, that adding GTR will significantly affect the expansion and contraction in the concrete pavement.