Study on dynamic modulus of polyurethane mixture: Impact factors and prediction models

Abstract

Polyurethane mixture (PUM) is proposed as an innovative and promising paving material due to its superior engineering performance and environmentally-friendliness. This study aims to experimentally investigate dynamic modulus of PUM at various temperatures, loading frequencies and loading strains. Furthermore, prediction models on its dynamic modulus considering factors of temperature, loading frequence as well as their coupling effect are proposed. The results demonstrate that dynamic modulus of PUM approximately varies between 2000 MPa and 19,000 MPa in temperature range of 15–50°C, loading frequency range of 0.1–25 Hz, and loading strains range of 20–100με. Dynamic modulus of PUM at 15°C is approximately 5.62 times higher than that at 50°C. The value at 20 Hz is approximately 2.76 times higher than that at 0.2 Hz. By implementing the analysis of variance (ANOVA) method, it is explored that temperature and loading frequency yield significant impact on dynamic modulus of PUM while loading strain imposes negligible influence on dynamic modulus of PUM. By statistical fitting analysis, dynamic modulus of PUM is linear with temperature and presents power function with loading frequency. Moreover, by considering coupling effect of temperature and loading frequency, prediction model on dynamic modulus of PUM is proposed and verified through experiments. The outcome of this study facilitates design and applications of PUM at different climate conditions and traffic loads.