Experimental study on the design and behavior of concrete pavement joint sealants

Joints in concrete pavement are intended to provide freedom of movement in a concrete slab relative to the volumetric effects. Changes such as this can occur owing to drying shrinkage, temperature changes, and moisture differences that develop within the slab. A key reason to seal the rigid pavement joints is to prevent, or at least reduce, the amount of water from rainfall events infiltrating the pavement structure, which can ultimately contribute to subbase erosion, loss of support, and the build-up of a fine, incompressible material on the face of the joint. The strength of the joint sealant bond and stress of the interface between the sealant and the face of the joint reservoir play important roles in joint sealant failure. Thus, in this research, experimental coupling tests were conducted to investigate the geometric characteristics of the sealant/joint reservoir design. The stress–strain relationship on the interface was investigated according to its geometry, both with regard to the shape factor (SF) and the degree of curvature (DoC). The SF and DoC were evaluated through a tensile test of the joint sealant based on these geometric characteristics. Also discussed are the shape factors (SFs) of the joint sealant currently being recommended, the SF most appropriate for a narrow-width joint, and the surface finish of the joint sealant. Based on this study, the effects of sealant geometries (i.e., SF and DoC) should be considered during design and installation. Also, further research into more realistic SFs for narrow-width joints and self-leveling sealants is recommended.