机械发泡温拌技术在高速公路沥青路面的应用

Application of Mechanical Foaming Warm Mix Technology in Asphalt Pavement of Expressway

热拌沥青的拌和及摊铺过程需要较高的温度,不仅会造成沥青的老化,而且产生的烟雾会危害施工人员的身心健康。为了降低沥青混合料施工过程中的老化现象和产生的烟雾,将沥青和微量水通过机械发泡装备制备了泡沫沥青。依托甘肃甜永高速公路对温拌沥青混合料进行了下面层的配合比设计,分析了机械发泡温拌沥青混合料应用在下面层的路用性能。重点研究了机械发泡温拌沥青技术的施工工艺,分析了机械发泡温拌沥青技术的经济效益和环境影响。结果表明:机械发泡温拌技术生产的沥青混合料强度、水稳定性和高温车辙性能均满足规范要求,试验路的空隙率、饱和度及矿料间隙率也均达到技术指标要求,表明了机械发泡温拌沥青技术在高速公路中的应用具有可行性;机械发泡温拌沥青混合料的出料温度、运输到现场温度范围分别为120~135℃,130~145℃,出料温度比普通热拌沥青混合料降低了约28℃,混合料的摊铺温度、初压温度以及终压温度分别不低于120℃,110℃和70℃;与传统热拌沥青混合料相比,采用机械发泡温拌工艺生产普通沥青混合料可节约燃气费用约6.8元/t,节能率达到26%;对机械发泡温拌沥青混合料施工现场实测发现二氧化碳、一氧化碳、二氧化硫以及烟尘排放量分别降低了44%,12%,48%和34%,表明机械发泡温拌沥青技术具有很大的经济和社会效益,极具推广价值。

The mixing and paving process of hot mix asphalt requires high temperature, which not only causes the aging of asphalt, but also the produced smoke will endanger the physical and mental health of the construction personnel. In order to reduce the aging phenomenon and generated smoke during the construction of asphalt mixture, the foamed asphalt is prepared with asphalt and trace water by mechanical foaming equipment, Relying on the Gansu Tianshuibao-Yonghe expressway, the mix proportion design of the lower surface course of the warm mix asphalt mixture is carried out, and the road performance of the mechanical foamed warm mix asphalt mixture applied in the lower surface course is analyzed. The construction process of mechanical foamed warm mix asphalt technology is studied, and the economic benefits and environmental influence of mechanical foamed warm mix asphalt technology are analyzed. The result shows that(1) The strength, water stability and high-temperature rutting performance of the asphalt mixture produced by mechanical foaming warm mix technology meet the requirements of the specification, and the air voids, saturation and ore gap rate of the test road also meet the technical indicator requirements, indicating that the application of the mechanical foamed warm mix asphalt technology in expressway is feasible.(2) The discharge temperature and transport to site temperature of mechanical foamed warm mix asphalt mixture are 120-135 ℃ and 130-145 ℃ respectively. The discharge temperature is about 28 ℃ lower than that of ordinary hot mix asphalt mixture. The paving temperature, initial compaction temperature and final compaction temperature of the mixture are not lower than 120, 110, 70 ℃ respectively.(3) Compared with the traditional hot mix asphalt mixture, the use of mechanical foaming warm mix process to produce ordinary asphalt mixture can save about 6.8 yuan/t of gas costs, and the energy saving rate reaches 26%.(4) According to the measurement on the construction site of mechanical foaming warm mix mixture, the emissions of carbon dioxide, carbon monoxide, sulfur dioxide and smoke and dust decreased by 44%, 12%, 48% and 34% respectively, indicating that the mechanical foamed warm mix asphalt technology has great economic and social benefits, which is worth popularizing.