Mechanical analysis and experimental study on the shear performance of waterproof adhesive layer toward concrete bridge deck pavement

Shear stress within the waterproof adhesive layer (WAL) of bridge deck pavement (BDP) makes it prone to shear-induced distresses. To mitigate this issue, a three-dimensional finite element model of BDP was developed. The maximum shear stresses in the WAL were calculated, and a shear strength index was proposed. Furthermore, a novel solvent asphaltic waterproof adhesive material (SAWAM) was formulated, and its shear resistance performance was examined through skew shear tests, considering the effects of bridge deck roughness, temperature, and shear rate. The results showed that vertical load had the greatest influence on WAL’s maximum shear stress, followed by temperature, vehicle speed, and horizontal load. Under the most unfavorable conditions, the maximum shear stress reached 0.4713 MPa, which was defined as the shear strength index. WAL’s shear strength decreased with rising temperature and was positively correlated with concrete slab roughness. According to the proposed index, under the most adverse testing conditions (50°C and a shear rate of 1 mm/min), grooved and milled WAL specimens exhibited normal performance, while the untreated interlayer tended to shear failure. This study presents an enhanced technical solution to improve interlayer bonding and extend the service life of concrete bridges.