Why use an epoxy bonding agent for placing repair concrete over old concrete?
Many applications and specifications call for low cost polyvinyl acetate based bonding agents for cementitious repairs. However, for installations of shallow patches, particularly those less than 6 inches deep, ACI 546R-96 suggests that polyvinyl acetate based bonders not be used in applications exposed to moisture or subject to occasional submersion. Most experts suggest use of an epoxy bonding agent under these conditions. Without the epoxy, thin repairs are subject to poor curing conditions caused by moisture evaporation and capillary absorption by the base concrete and thus rarely develop acceptable bond strengths.
