旧水泥路面改扩建拼接结构优化及性能评价

Optimization and Performance Evaluation of Old Cement Pavement Reconstruction and Expansion Splicing Structure

针对目前旧水泥混凝土路面改扩建路面拼接结构的特征和缺陷,对新旧水泥混凝土路面拼接结构进行优化设计.水泥混凝土面板拼接缝设置在旧水泥混凝土面板的硬路肩上,在旧路上基层、旧路下基层、旧路垫层设置台阶作为过渡,扩建部分的新路上基层采用贫混凝土,路床采用未筛分碎石;新旧水泥混凝土面板采用双层钢筋来连接;水泥混凝土面板拼接缝上,先粘贴高分子聚合物抗裂贴,再加铺沥青混凝土抗裂调平夹层,最后再依次加铺沥青混凝土下面层、上面层,其中沥青混凝土下面层掺质量百分比为0.3%且长度为6 mm的短切玄武岩纤维.运用Abaqus软件,对新旧水泥混凝土路面拼接缝处沥青层底的受力、台阶宽度,以及受荷板板底竖向位移进行了分析.结果表明:拼接后路面的疲劳损伤寿命得以延伸,路面结构整体强度提高,路用性能得到有效提升,经济效益显著.

According to the characteristics and defects of the splicing structure of the existing cement concrete pavement reconstruction and expansion,the splicing structure of the new and old cement concrete pavement was optimally designed.Cement concrete panel stitching seams were arranged on the hard road shoulders of the old cement concrete panel,and steps were arranged on the upper base layer,the lower base layer and the cushion layer of the old road as transitions.The new road base of the extension part was made of lean concrete,the road bed was made of unscreened crushed stone,and the new and old cement concrete panels were connected by double-layer steel bars.On the joint of cement concrete panels,high molecular polymer anti-cracking paste was pasted first,then asphalt concrete anti-cracking leveling interlayer was additionally paved.Finally,a lower layer and an upper layer of asphalt concrete were sequentially paved,wherein the lower layer of asphalt concrete was mixed with chopped basalt fibers with a mass percentage of 0.3%and a length of 6 mm.Abaqus software was used to analyze the stress,step width and vertical displacement of asphalt layer bottom at the joint of new and old cement concrete pavement.The results show that the fatigue damage life of the spliced pavement can be extended and the overall strength of the pavement structure can be greatly improved.The pavement performance can be effectively improved,and the economic benefits are remarkable.