旧水泥混凝土路面加铺沥青结构性能动力评价研究

发布时间：2018-04-19 18:03

本文选题：复合路面 + 结构性能　；参考：《福州大学》2014年硕士论文

【摘要】：目前有关旧水泥混凝土路面加铺沥青复合路面结构的理论研究、数值模拟研究已十分广泛,但基于现场监测和具体结构试验评价的比较研究则相对缺乏。鉴于此,本文结合具体试验路工程,重点开展旧水泥混凝土路面加铺沥青结构性能动力评价方法和工程实践研究。具体包括复合路面落锤弯沉特性动力数值模拟分析,水泥混凝土加铺沥青复合路面的落锤弯沉评价方法、现场复合路面试验路的动力试验检测,不同复合路面结构性能的现场评估,具体研究成果与结论如下：复合路面结构在脉冲荷载作用下的弯沉盆曲线,离荷载作用中心点距离越远,相应各测点的弯沉值越小,各个测点的弯沉值与距荷载作用中心点距离成近似反比关系。各点弯沉时程曲线存在上下波动现象,随时间逐渐衰减于零。复合路面弯沉盆曲线大致为一条凸曲线,一般弯沉盆曲线存在明显拐点,反映沥青加铺层与旧水泥混凝土面板模量的突变,路面顶面沥青结构模量相对面板越柔、厚度越大折线越大。对复合路面弯沉敏感性最高的是旧水泥混凝土板模量,其次是土基模量,沥青混合料模量。其中,土基模量并不改变复合路面的折线形式,但会改变整体的弯沉幅值(整体平行下移),以及最后几个弯沉点离开零点的幅度。对于水泥混凝土加铺沥青路面,荷载中心弯沉越大,且曲率越连续,说明旧水泥混凝土板破损破碎越严重。基层模量与沥青面层模量的大小关系,影响复合路面荷载中心点弯沉随沥青面层厚度增加的的变化特性。旧水泥稳定基层模量小于沥青加铺层模量时,沥青加铺层厚度越大,复合路面弯沉越小；当旧水泥稳定基层模量大于沥青加铺层模量时,沥青加铺层厚度越大,复合路面弯沉越大。提出了复合路面承载力指标和分级。提出以水泥混凝土路面代表弯沉为下限、沥青路面平均弯沉为上限,采用荷载作用中心点弯沉d0评价复合路面性能接近沥青路面的趋势的柔化系数指标和分级。试验路对八种典型复合路面结构的评价发现,“白加黑”复合路面结构比“白改黑”承载能力高,其中,应力吸收层+12cmAC复合路面承载力最高;“白改黑”复合路面比“白加黑”更具柔性,其中,旧水泥混凝土板碎石化+20cm沥青面层复合路面结构柔化系数最高,柔性最好。综合考虑复合路面承载力和柔化系数,对于旧水泥混凝土路面加铺沥青改建复合路面工程中,建议旧水泥混凝土板采取打裂处理方式。
[Abstract]:At present, the theoretical research on asphalt composite pavement structure of old cement concrete pavement is very extensive, but the comparative study based on field monitoring and concrete structure test evaluation is relatively lacking.In view of this, this paper focuses on the dynamic evaluation method and engineering practice of asphalt overlay structure of old cement concrete pavement combined with the concrete test road project.It includes the dynamic numerical simulation analysis of the overlay deflection characteristics of composite pavement, the evaluation method of concrete overlay asphalt composite pavement, and the dynamic test test of the field composite pavement test road.The concrete research results and conclusions of the field evaluation of the performance of different composite pavement structures are as follows: the more distance from the center of load, the smaller the deflection value of each measuring point of composite pavement structure under the action of pulse load.The deflection value of each measuring point is approximately inversely proportional to the distance from the center of the load.The curve of deflection time history of each point fluctuates up and down, and gradually attenuates to zero with time.The deflection basin curve of composite pavement is about a convex curve, and the curve has obvious inflection point, which reflects the sudden change of the modulus of asphalt overlay and old cement concrete slab, and the softer the modulus of asphalt structure on the top of pavement is relative to the slab.The greater the thickness, the larger the broken line.The modulus of the old cement concrete slab is the most sensitive to the deflection of the composite pavement, followed by the modulus of the soil foundation and the modulus of the asphalt mixture.Among them, the modulus of soil foundation does not change the curve form of composite pavement, but it will change the deflection amplitude of the whole (the whole parallel downward shift, and the amplitude of the last few deflection points leaving zero point).For cement concrete overlay asphalt pavement, the greater the deflection of the load center and the more continuous curvature, the more serious the damage and breakage of the old cement concrete slab.The relationship between base modulus and asphalt surface modulus affects the variation of load center deflection of composite pavement with the increase of asphalt surface thickness.When the modulus of old cement stabilized base is smaller than that of asphalt overlay, the greater the thickness of asphalt overlay, the smaller the deflection of composite pavement, and the greater the thickness of asphalt overlay is when the modulus of old cement stabilized base is greater than that of asphalt overlay.The greater the deflection of the composite road.The bearing capacity index and classification of composite pavement are put forward.Taking the representative deflection of the cement concrete pavement as the lower limit and the average deflection of the asphalt pavement as the upper limit, the flexibility coefficient index and classification of the composite pavement performance close to the trend of asphalt pavement are evaluated by the load action center point deflection d0.The evaluation of eight typical composite pavement structures shows that the load-carrying capacity of "White plus Black" composite pavement is higher than that of "White to Black", among which, the bearing capacity of 12cmAC composite pavement with stress absorption layer is the highest."White to black" composite pavement is more flexible than "white plus black". Among them, the softness coefficient of old cement concrete slab 20cm asphalt pavement is the highest and the flexibility is the best.Considering the bearing capacity and softness coefficient of the composite pavement, it is suggested that the old cement concrete slab should be cracked in the asphalt overlay reconstruction of the old cement concrete pavement.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.217

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