沪苏通长江公铁大桥主航道桥公路钢桥面铺装技术研究

沪苏通长江公铁大桥主航道桥公路钢桥面铺装采用“环氧沥青混凝土EA10+高弹改性沥青混凝土SMA-10”结构。针对铺装材料受力复杂、低温施工难度大及摊铺时降温速度过快等技术难题,从关键环氧类铺装材料性能、钢桥面铺装施工工艺和环氧沥青混凝土EA10保温措施3个方面开展研究。结果表明:国产环氧树脂粘结料和环氧沥青的23℃拉伸强度、断裂伸长率均优于同类进口产品,国产环氧沥青混凝土EA10的强度相比同类进口产品提高了10%,路用性能良好;环氧沥青在施工前进行预加热处理,以保障其低温施工和易性;环氧沥青混凝土EA10摊铺后前20 min升温、后期迅速降温;通过设置挡风墙、利用当日高温时段进行施工、增加30%的压实机械、优化施工碾压工艺等措施,有效保障了低温条件下大桥公路钢桥面的铺装施工质量。

Research on Steel Highway Deck Paving Techniques for Main Navigational Channel Bridge of Shanghai-Suzhou-Nantong Changjiang River Rail-cum-Road Bridge

The steel highway deck of main navigational channel bridge of Shanghai-Suzhou-Nantong Changjiang River Rail-cum-Road Bridge is paved with epoxy asphalt concrete EA10 and highly-elastic modified asphalt concrete SMA-10.The placement of pavement faced a series of technical challenges,for instance,the complex mechanical property of the materials,low-temperature construction environment and fast dropping of temperature during placement.To address this issue,studies were carried out from aspects of mechanical properties of key epoxy pavement materials,steel deck paving techniques and thermal insulation for epoxy asphalt concrete EA10.The results show that the tensile strength and breaking elongation of the domestic epoxy resin binders and epoxy asphalt at 23℃are better than similar imported products,and the strength of domestic epoxy asphalt concrete EA10,compared with similar imported products,is improved by 10%,which is a better choice for road pavement.The epoxy asphalt should be heated before placement to ensure its workability at low temperatures.The epoxy asphalt concrete EA10 was heated 20 minutes before placement,and rapidly cooled during placement.A series of measures were taken to ensure the placement quality of the highway steel deck pavement at low temperatures,including installing wind walls,placing within the high temperature period of a day,supplying 30%compaction equipment,and optimizing compaction technique.