Experimental Investigation of Direct Tension Bond Performance of High-Strength Concrete and Ultrahigh-Performance Concrete Connections

Abstract

The outstanding mechanical and bond strength properties of ultrahigh-performance concrete (UHPC), as well as its long-term durability, make it a suitable material to be used in connections of accelerated bridge construction (ABC). However, the long-term performance and durability of these connections depends on the interface performance between UHPC and prefabricated bridge elements. If debonding failure develops along the interface, the load transfer and durability of these connections may be compromised. This study examined the bond performance between high-strength concrete (HSC) and UHPC under direct tension stress states at different ages and using different surface preparations. The results from this study determined that a sufficient bond strength of UHPC could be assessed even at early ages when good surface preparation was utilized. Furthermore, the properties of the aggregate played a vital role in the interface bond strength. The bond versus slip was investigated at different ages and can be used in future analytical studies to obtain more accurate modeling of HSC–UHPC interfaces.