环氧树脂/聚氨酯复合改性沥青及其混合料性能研究

Studyon performance of epoxy resin/polyurethane composite modified asphalt and its mixture

针对环氧沥青柔韧性差、低温下沥青路面易产生裂缝的缺陷,本研究选用环氧树脂(EP)、聚氨酯(PU)和90号基质沥青制备EP/PU复合改性沥青,并以此为结合料制备了AC-13沥青混合料。利用傅里叶红外光谱仪(FTIR)和原子力显微镜(AFM)对EP/PU复合改性沥青反应机理和微观结构等进行了分析;通过车辙试验、小梁弯曲试验、浸水马歇尔试验和冻融劈裂试验分别研究了EP/PU复合改性沥青混合料高温稳定性、低温抗裂性以及水稳定性,并与环氧沥青混合料和PU改性沥青混合料进行性能对比。结果表明,复合改性过程中环氧基、酸酐羰基C=O、-NCO以及-OH可以进行化学反应,生成醚键C-O-C和酯基C=O;与基质沥青相比,复合改性沥青中“蜂形”结构不明显,连续相与分散相边界模糊,表面粗糙度增加,与集料接触面积增加。EP/PU复合改性沥青混合料拥有良好的综合路用性能。EP/PU复合改性沥青混合料高温稳定性和水稳定性相较于环氧沥青混合料有所降低,但低温抗裂性得到改善。

In view of the defects of poor flexibility of epoxy asphalt and easy cracks of asphalt pavement at low-temperature,in this study,epoxy resin(EP),polyurethane(PU)and No.90 base asphalt were selected to prepare EP/PU composite modified asphalt,and AC-13 asphalt mixture was prepared by using this binder.The reaction mechanism and microstructure of EP/PU composite modified asphalt were analyzed by Fourier infrared spectrometer(FTIR)and atomic force microscope(AFM).The high-temperature stability,low-temperature crack resistance and water stability of EP/PU composite modified asphalt mixture were studied by rutting test,trabecular bending test,immersion Marshall test and freeze-thaw splitting test,and compared with the performance of epoxy asphalt mixture and PU modified asphalt mixture.The results show that the epoxy group,acid anhydride carbonyl group C=O,-NCO and-OH could undergo chemical reactions during the composite modification process to form ether bond C-O-C and ester group C=O.Compared with the base asphalt,the"bee-shaped"structure in the composite modified asphalt was not obvious,the continuous phase and the dispersed phase were blurred,and the surface roughness and the contact area with the aggregate increased.EP/PU composite modified asphalt mixture had good road performance.The high-temperature stability and water stability of EP/PU composite modified asphalt mixture were slightly lower than that of epoxy asphalt mixture,but the low-temperature crack resistance was improved.