Experimental study on the shear performance of the bonding interface between geopolymer concrete and cement concrete

To investigate the mechanical performance of geopolymer concrete as a strengthening material for bridge deck pavement, this study examined the bonding performance between geopolymer concrete and cement concrete through direct shear and inclined shear tests. The influence of section treatment methods, steel fiber volume ratio, and fiber length on bonding performance was considered, leading to the establishment of a bonding strength formula and a bond-slip constitutive model. The results indicate that untreated and grooved sections primarily exhibit bond surface failure, whereas chiseled sections show failure on the cement concrete side. Section treatment method is the most significant factor affecting bonding performance. A volume ratio of 2.5 % for end-hooked steel fibers with a length of 35 mm yields the best improvement in bonding performance. This study derived a theoretical formula for bonding strength and established a bond-slip constitutive model, providing a theoretical basis for the application of geopolymer concrete in bridge deck pavement strengthening.