关键词: 粗糙度;粘结强度;丙乳净浆;微观形貌;显微硬度;

Abstract: In order to explore the influence mechanism of base roughness on the bonding characteristics between acrylic emulsion paste repair material and concrete interface, four kinds of concrete substrates with different roughness were prepared by cutting and chiseling.The bonding strength and failure mode of acrylic emulsion paste-concrete at different ages were obtained by directly pull-out test.Based on polarizing microscope and micro-hardness tester, the micro-structure and mechanical properties of acrylic emulsion paste-concrete were studied.The following conclusions were obtained: the surface layer of concrete substrate after chiseling treatment had been obvious damaged, and the micro-hardness of interface area was smaller than that of cutting treatment and there was a large fluctuation.This was the direct reason for the low bond strength and the damage of the substrate surface.The interface bonding form between the acrylic emulsion paste and the cut concrete substrate was good, and the micro-hardness of the interface area was close.The stripe and grid substrate surfaces could provide a mechanical bite force for the acrylic emulsion paste and the substrate, and the overall bond strength was higher than that of the flat interface.In practical engineering, it is recommended to use the strip cutting method to treat the concrete substrate surface to achieve a good bonding quality.

Key words: roughness; bonding strength; acrylic emulsion paste; micro-morphology; micro-hardness;