Thin ECC overlay systems for rehabilitation of rigid concrete pavements

The use of rigid overlays has become increasingly popular. The main purpose of an overlay is to extend the service life of the structure and increase the structural performance and durability of a wearing surface. The superior ductility and durability characteristics of engineered cementitious composites (ECC) suggest that they could be used as an attractive alternative to conventional concrete overlay materials. In this study, the performance of ECC overlay designed at different thicknesses is investigated by laboratory experiments. Micro-silica concrete (MSC), generally used as an overlay material, is also prepared as a control mixture. The test results show that, for the same geometry and loading conditions, layered ECC beams have significantly increased both load-carrying capacity and deformability, and show better crack width control in comparison with MSC composite beams. As the overlay material, ECC is also found to be effective in eliminating the reflective cracking and delamination failure in repaired systems.