Experimental evaluation of concrete-to-UHPC bond strength with correlation to surface roughness for repair application

By A. Valikhani, Azadeh Jaberi Jahromi, Islam M. Mantawy, A. Azizinamini. 2020

219 citations recorded by the source corpus.

Abstract Exposing bridge elements to severe environmental conditions causes a reduction in service life and durability which demands repair or total replacement. Different strategies for repair and retrofit can be chosen. These strategies include patching, crack repairs, concrete sealers, a protective layer made of concrete or steel. Ultra-high performance concrete offers an option for repairing and retrofitting different structural elements, however, the bond strength between concrete substrates and ultra-high performance concrete can still be considered a knowledge gap in the literature. In this paper, bond strength between ultra-high performance concrete and substrate made of normal concrete with different surface preparation was investigated experimentally. Thirty specimens were tested under bi-surface shear test with different surface preparation, including roughness degree, mechanical connector, and bonding agent. Furthermore, two non-contact test methods including terrestrial laser scanning and digital image processing were incorporated to evaluate the roughness of the substrate interface and correlate the roughness degree to the bond strength between the two materials. The results showed that an adequate roughness for the interfacial surface with or without mechanical connectors transferred the failure mode to the concrete substrate indicating high bond strength between the two materials if compared to interfacial surfaces without any preparat;ion. In addition, the use of bonding agent could harm the bond strength between the two material which is inappropriate for retrofitting. The result from scanning and image processing showed that both methods qualitatively identified the degree of interface roughness and their result can be correlated to bond strength.

Subfields: Civil and Structural Engineering

View Paper: https://www.semanticscholar.org/paper/abbe5502ae138970ad0f8bfe6deb625c519420be