聚氨酯玛蹄脂混合料的设计及性能

Design and Performance of Stone Matrix Polyurethane

研究高性能的环境友好型路面材料对经济、环境具有重要的意义。采用聚氨酯胶粘剂代替沥青作为结合料,设计出密实型聚氨酯玛蹄脂混合料(SMPU)。通过飞散试验、析漏试验以及马歇尔试验对SMPU进行配合比设计,以SBS改性沥青混合料(简称SMA)做对比,通过车辙试验、单轴贯入试验、浸水马歇尔试验、冻融劈裂试验以及低温弯曲试验,对SMPU的路用性能进行了评价,并通过不同温度、不同浸泡方式下的抗压、抗折以及劈裂试验,考察了SMPU的力学性能。结果表明:SMPU具有比SMA更优异的高低温及水稳定性能,但负温-水的耦合作用会对其造成较大影响;SMPU的温度敏感性低,在路面正常工作温度内,SMPU的抗压、抗折及劈裂强度分别为17~21 MPa、2.9~3.6 MPa及1.7~1.9 MPa;在不同浸泡方式下,SMPU的3种强度损失率均<7%,能有效抵抗常温下的水损伤。拟合试验数据显示,基于SMPU抗压强度的抗折与劈裂强度转换式相关性高,可为密实型聚氨酯混合料强度相关研究提供参考。在绿色公路建设及路面变形严重区域,SMPU具有广阔的应用前景。

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.