Abstract: Studying high-performance environmental-friendly pavement material is of great significance to economy and environment. A dense polyurethane mastic mixture (SMPU) was designed by using polyurethane adhesive instead of asphalt as binder. The mix ratio of SMPU was designed according to Cantabro scattering loss test, Schellenberg binder drain-down test and Marshall test. With SBS modified asphalt mixture (SMA) as a comparison, the road performance of SMPU was evaluated by rutting test, uniaxial penetration test, immersion Marshall test, freeze-thaw splitting test and low-temperature bending test. The mechanical properties of SMPU were also investigated by compression, bending and splitting tests at different temperatures by different immersion types. Results demonstrate that SMPU has better stability in high and low temperatures and water than SMA; but is greatly affected by the coupling of negative temperature and water. SMPU is lowly sensitive to temperature, and its compressive strength, flexural strength and splitting strength are 17-21 MPa, 2.9-3.6 MPa and 1.7-1.9 MPa, respectively. Under different soaking methods, the loss rates of compressive strength, flexural strength and splitting strength of SMPU are less than 7%, which means that SMPU can effectively resist water damage at normal temperature. Fitting of test data suggest that the conversion formula of flexural strength and splitting strength based on SMPU compressive strength is of high correlation, which offers a reference for the strength-related research of dense polyurethane mixture. In conclusion, SMPU has broad application prospects in green highway construction and areas with severe pavement deformation.

Key words: road engineering, stone matrix polyurethane, mix ratio, road performance, mechanical property