Research and Innovative Technology Administration
Most pavement projects today are a rehabilitation or rejuvenation of existing and distressed pavements. We often add more overlay layers or mill out patches for repair material rather than reconstruct the entire roadway. One of the key requirements for those repair systems is to have adequate bond strength between the existing concrete substrate and overlay throughout the service life. When a repair is performed, the differences in the properties of two materials will affect bond strength and stress distribution. Of particular relevance are differences in shrinkage, elastic modulus and thermal movement. Repaired sections of concrete pavement often fail due to debonding or delamination of the top repaired layer. Thus there is a need to improve or to maintain the bond by improved material properties or improved interface conditions.