施工参数对热拌环氧沥青混合料性能的影响研究

Study on the Influence of Construction on Performance of Hot-mixed Epoxy Asphalt Mixture

热拌环氧沥青在我国钢桥面铺装上的应用已长达十五年之久,现结合苏通大桥养护工程,利用现场热拌环氧沥青混合料的施工,从容留时间、养生时间、养生温度、桥面振动、施工缝五个方面来分析施工因素的变化对热拌环氧沥青混合料性能的影响,为指导施工提供技术支撑。研究发现,热拌环氧沥青混合料容留时间越长,混合料空隙率越大,强度明显下降;强度随养生时间的延长逐步增大,室外养生5 d后趋于稳定;室外养生温度越高,混合料所需养生时间越短;桥面振动对固化初期的环氧沥青混合料强度和抗高温水损坏有一定影响,抗冻劈裂强度基本无影响;施工缝和裂缝处铺装层的回弹强度明显低于常规铺装层,不同类型裂缝扩展至5 cm时,铺装层强度恢复正常。

Hot-mixed epoxy asphalt has been used in steel bridge deck pavement in China for 15 years.In this paper,combined with the maintenance project of Sutong Bridge,the influences of construction of reserved time,curing time,curing temperature,bridge vibration and construction joints on the performance of hot-mix epoxy asphalt mixture were analyzed,in order to provide technical support for guiding construction.The study found that the longer the reserved time of the hot-mix epoxy asphalt mixture,the greater the void ratio of the mixture could achieve,and the strength could decrease significantly.The strength gradually increased with the extension of the curing time,and the strength tended to be stable after five days of outdoor curing.The higher the outdoor curing temperature,the shorter the time was required for the mixture.Bridge deck vibration had certain effect on the strength of the epoxy asphalt mixture in the early stage of curing and resistance to high temperature water damage.The resistance to frost splitting had basically no effect.The rebound strength of the pavement at the construction joints and cracks was significantly lower than that of the conventional pavement.When the different types of cracks extended to 5cm,the pavement strength returned to normal.