Curing Law and Strength-Age Prediction Model of a Dense Polyurethane Mixture under the Influence of Moisture and Temperature

Abstract

The strength development of pavement polyurethane mixture is primarily dependent on the degree of curing reaction of polyurethane adhesive. In this work, the effects of temperature, humidity, and curing time on the curing rate of a dense polyurethane mixture, stone mastic polyurethane mix (SMPU), were investigated. Two strength-age prediction models were established to forecast the compressive strength and the splitting strength development of SMPU under different curing conditions, respectively. The results indicate that the optimal curing conditions for SMPU are at a temperature of 30°C and a humidity of 55%. Furthermore, the two types of strength of cured SMPU can exceed 90% of their corresponding maximum strength values, respectively, when cured at temperatures between 20°C and 40°C, and at a humidity range of 30% to 70%. Finally, the validity of the strength-age prediction models was confirmed through experiments, thereby providing a theoretical basis and reference for on-site construction technology of SMPU.