Influence of Wetting Conditions and Concrete Strength of Both Substrate and Repair Material on the Bond Capacity of Repaired Joints

Ultra-high performance concrete (UHPC) is an appropriate material to repair and rehabilitate aged structures due its excellent properties, such as high compressive strength durability. Several studies have demonstrated the effectiveness of applying UHPC in old buildings a rehabilitation or material, but bond between concretes needs more investigation. In this sense, normal-strength (NSC) currently being studied. Three main parameters are responsible for ensuring good bond: surface treatment substrate (roughness), wetting conditions, mechanical substrate. Thus, present study investigated experimentally. The was carried out three grades: C25, C45, C60. were C60, UHPC. following evaluated: air dry (ASD), saturated (SSD), strength, strength. All models received by wire brushing. Slant shear splitting tensile tests performed evaluate behavior failure modes concretes. classified compared existing predicting models. results showed that most expressive gains occurred SSD with lower substrates Furthermore, influence conditions becomes smaller reduced.