Effect of impact treatment methods with different energy and frequency on roughening and tensile bond of concrete-concrete interfaces

Impact treatment methods that increase surface roughness usually cause near-to-surface damage to concrete. Quantitative analysis of this damage on the bond strength is rare. In this article, a concrete surface was reproduced by an undamaged engraving method, and then surface curing agents were used to repair the damage. Direct tension tests show that the bond strengths of new to old concrete caused by surface damage of low-frequency high-energy (LFHE) and low-frequency medium-energy (LFME) impacts were reduced by 41.96% and 41.42%, respectively. Concrete surface curing agents led to the formation of crystalline films that negatively affected the interfacial bond strength. •Quantifying how surface damage from varied impact strengths affects bond strength.•Engraving replicates concrete surface roughness without damage.•Pigment tech gauges aggregate 2D ratio; same-batch concrete shows minor dispersion.•Silicate-based curing agent negatively affects bonding due to crystal film formation.