Evaluation of bond strength between fire-damaged normal concrete substance and ultra-high-performance fiber-reinforced concrete as a repair material

Abstract

Purpose This study aims to investigate and compare the interfacial bond characteristics between fire-damaged normal concrete substrate and ultra-high-performance fiber-reinforced concrete (UHPFRC) as a repair material. Design/methodology/approach First, fire-damaged normal concrete was prepared. Then, with a cast surface, the substrate was subjected to different surface moisture conditions. Three types of moisture conditions were set, namely, air dry, saturated surface dry (SSD) and wet. Slant shear and splitting cylinder tests were conducted to determine the interfacial bond strength of the composite. Findings In general, results indicate that surface moisture conditions significantly influence bond strength. The substrate under SSD condition exhibited the highest bond strength. The findings suggest that UHPFRC is a promising material for the repair and reuse of fire-damaged concrete structures. Originality/value This study compares the bond strength between fire-damaged normal concrete and UHPRC.