增强纤维对沥青混凝土路用性能影响的研究

Study on reinforced fibre influence to road performance of asphalt concrete pavement

通过将增强纤维加入沥青混凝土中制成试件,与普通沥青混凝土进行一系列的对比试验,研究了纤维加入后沥青混合料的最佳沥青用量、密度、空隙率、矿料间隙率、饱和度和流值等马歇尔技术指标的变化;分析了纤维对沥青混凝土的高温稳定性、低温抗裂性能、抗劈裂特性、耐水害性能等路用性能的影响;探讨了纤维作用机理,并通过试验路段铺筑总结出纤维沥青混合料施工技术和经济指标等.室内研究表明:纤维加入后,最佳沥青用量、空隙率、矿料间隙率、稳定度和流值均有不同程度增加,而密度下降;高温稳定性、低温抗裂性能、抗劈裂特性和耐水害性能等路用性能均有明显改善.试验路铺筑结果表明:纤维沥青混合料具有良好的使用效果,可延长道路使用寿命,降低养护成本,有较好的经济和社会效益.

The traditional pavement materials could not solve the problems such as earlier surface breakdowns, insufficient usage life, lower surface performance, ruts and cracks appeared on the asphalt concrete pavement. The advanced pavement materials and improved technology should be developed and introduced. Ningxia Highway Administration Bureau based on the provincial 201 rebuilt engineering project did the research of subject “fiber asphalt mixtures experimental road”in year 2000. Samples were made through adding the strengthened fiber into the asphalt concrete. The test results were compared with the common asphalt concrete. The changes of Marshal technical indexes were studied, such as optimum asphalt content, density, air void rate, clearance rate of the mineral powder, saturation degree, and flow value of the asphalt mixtures with fiber. The road performance influenced by additional fiber was analyzed, i.e. the stability of asphalt concrete under high temperature condition, anti crack ability under low temperature condition, anti splitting character, and water resistance. The fiber function mechanism was discussed. And the construction technology and economic index of the fiber asphalt mixtures were concluded through paving the experimental road section. It was showed through the indoor research that the optimum asphalt content, air void rate, clearance rate of the mineral powder, saturation degree, and the flow value increased and the density were decreased after adding the fiber. The road performance (such as stability of asphalt concrete under high temperature condition, anti crack ability under low temperature condition, anti splitting character, and water resistance) was obviously improved. The result of paving the experimental road section showed that the fiber asphalt mixture had good usage effect, longer road usage life, lower maintenance cost, and better economic and social benefit.