Research on drying shrinkage deformation and cracking risk of pavement concrete internally cured by SAPs

Abstract

Drying shrinkage and cracking are important factors affecting the performance and service life of pavement concrete directly, and they can be effectively alleviated by internal curing with super absorbent polymer (SAP). The influence of SAP on drying shrinkage and humidity distribution was investigated via displacement and humidity sensors. Moreover, the inner wall strain of pavement concrete with or without SAP was analyzed, and the risk of cracking was evaluated under the condition of annular restraint. The results show that the internal curing with SAP could reduce the shrinkage strain at the center and corners of the pavement slab and be accompanied by a decrease in the humidity difference between the upper, middle and lower layer of the slab, which is extremely beneficial for suppressing the humidity warping stress of the pavement slab. The internal curing with SAP was the most effective for the shrinkage of the pavement slab within 7 days, and then, the anti-shrinkage effect began to decrease. After internal curing with SAP, the cracking risk of concrete was degraded, and cracking could be avoided.