摘要
单组份聚氨酯是一种反应型胶黏剂,其力学性能优于常规沥青结合料,但聚氨酯的反应过程易受到温度、空气、水等环境因素的影响。在聚氨酯混合料的摊铺、碾压施工过程中,需结合现场温、湿度工况,严格把控各工序施工时间节点。为了普及单组份聚氨酯在道路方面的应用,对单组份聚氨酯的固化规律及黏结特性进行了研究,分别通过傅里叶红外光谱、拉拔试验、剪切试验研究了2种单组份的固化规律和黏结特性。试验结果表明:在自然固化条件下,PU-I和PU-II的异氰酸酯指数逐渐下降,而脲基指数则逐渐增长;固化4 d后,聚氨酯的异氰酸酯含量和脲基含量变化较小,且4~7 d的PU-I的异氰酸酯指数和脲基指数的变异系数分别为10%、2%,PU-II的异氰酸酯指数和脲基指数的变异系数均为2%,属于小变异,表明该材料已基本达到完全固化状态。聚氨酯黏结体系的拉拔强度和剪切强度随着固化时间的增加呈增大的趋势,且石料-聚氨酯-石料黏结体系界面间的拉拔、剪切强度均优于石料-聚氨酯-橡胶、橡胶-聚氨酯-橡胶黏结体系,橡胶-聚氨酯-橡胶黏结体系界面的拉拔强度最差,石料-聚氨酯-橡胶黏结体系的剪切强度最差。
Monocomponent polyurethane is a reactive adhesive,and its mechanical properties are better than those of conventional asphalt binders,but the reaction process is easily affected by environmental factors such as temperature,air and water,etc.During the paving and rolling construction of polyurethane mixes,it is necessary to strictly control the construction time nodes of each process in combination with the site temperature and humidity working conditions.In order to popularize the application of single-component polyurethane in road,curing and adhesive characteristics of monocomponent polyurethane were studied in this paper.Curing and adhesion characteristics of two single-component polyurethane(PU)binders were studied from FTIR,pull-out and shear tests.With the increase of natural curing conditions,the results showed that the isocyanate index of PU-I and PU-II decreased,while the urea index had the opposite trend.Both the isocyanate index and urea index of PU were stable after 4 days natural curing,and the variation coefficients of isocyanate index and urea index of PU-I and PU-II were 10%and 2%,2%and 2%,respectively in 4-7 days,which belong to small variations,indicating that PU had basically reached the fully cured state.With the increase of curing time,the pull-out strength and shear strength of polyurethane bonding system generally increased,and the pull-out and shear strength of stone-polyurethane-stone interface were better than those stone-polyurethane-rubber,rubber-polyurethane-rubber bonding system.The pull-out strength of rubber-polyurethane-rubber interface was the worst,and the shear strength of stone-polyurethane-rubber interface was the worst.
作者
钟科
王雪
张勐
孙明志
孙晟凯
龚演
ZHONG Ke;WANG Xue;ZHANG Meng;SUN Mingzhi;SUN Shengkai;GONG Yan(College of Civil Engineering, Chongqing Jiaotong University, Chongqing 400041, China;Research Institute of Highway Ministry of Transport, Beijing 100088, China;Key Laboratory of Transport Industry of Road Structure and Material, Beijing 100088, China)
出处
《郑州大学学报（工学版）》
CAS
北大核心
2021年第6期80-84,92,共6页
Journal of Zhengzhou University（Engineering Science）
基金
国家自然科学基金资助项目(51908261)。
