Influence of Temperature on the Mechanical Properties of Modified Low Exothermic Polyurethane Grouting Material and Engineering Applications

Low exothermic polyurethane grouting material, as a new type of material, is used for road reinforcement and repair engineering in frozen earth areas. This study investigates the mechanical properties of this grouting material under different ambient temperatures. The effects of temperature and density on the expansion pressure, compressive strength, and tensile strength of the materials were determined in this study. The characteristics of the material's stress–strain curves were analyzed microscopically. The results demonstrate that temperature significantly influenced the material properties. The expansion properties of the material decreased with decreasing temperature. In contrast, the tensile and compression properties of the material increased with decreasing temperature, which is shown in the tensile and compressive strengths. From the view of failure mode, lower temperature makes the material more brittle. Moreover, the constitutive model based on the temperature variation was established according to the experimental results. This provides a basis for a simple evaluation of the compressive strength and elastic modulus of materials. Finally, the mechanical response of road cavitation in cold areas before and after repair was analyzed through finite-element numerical simulation and full-scale model test. The low exothermic polyurethane grouting material effectively reduced the vertical deformation of the wheel load in the distressed area. This study provides a reference for road reinforcement and repair projects in cold regions.