再生沥青混凝土桥梁路面的动力响应研究

Dynamic Response of Recycled Asphalt Concrete Bridge

目的再生沥青混凝土路面由于其极大节省路面原材料而越来越得到广泛应用,其可行性及物理性能已得到广泛研究,但关于其承受动荷载的能力则急需验证。方法在桥梁的设计和评估中,冲击系数(IM)是桥梁结构动力响应的一个重要标准,其大小是否合理直接反应桥梁承受汽车冲击荷载的能力。通过三维车桥模型计算再生沥青混凝土路面和普通沥青混凝土路面的冲击系数。结果将计算的冲击系数值与国内规范值进行比较,并讨论两种路面的冲击系数随路面不平整度、速度的变化规律。结论在正常运营路面条件下,再生沥青混凝土路面的冲击系数可以满足国内规范要求,且在其它条件相同的情况下,再生沥青混凝土路面的冲击系数随路面不平整度、速度的变化规律与普通沥青路面的冲击系数基本相同。

Objective With the rapid development of traffic system,recycled asphalt concrete pavement is more and more widely used because of its enormous saving of pavement raw materials.The feasibility and physical properties of this kind of road material have been extensively studied,but its ability to withstand dynamic loads is in urgent need of verification.Methods In the design and evaluation of bridges,the impact factor（IM）is an important criterion for the dynamic response of bridge structures,which directly reflects the ability of the bridge to withstand the impact load of the automobile.In this study,impact factors of two kinds of surface material were calculated,i.e.,ordinary concrete road surface and road surface with application of recycled asphalt concrete with a three-dimensional vehicle-bridge coupled model.Results The calculated impact factors were compared with the standard values in our country,and the variation law of the impact factors of two kinds of pavements with the road roughness and velocity was discussed.Conclusion The results show that in the normal operation of the road conditions,the impact factors of recycled asphalt concrete can meet our Chinese bridge design code;under the same conditions,the changing relationship between the impact factors of the speed and road roughness condition were basically the same as the two kinds of surface material.