现行规范旧水泥混凝土路面加铺层设计的若干问题研究

Study on Some Problems in Current Specifications for Design of Overlay on Old Cement Concrete Pavement

结合潭耒高速公路旧水泥混凝土路面提质改造工程,针对目前国内常用的CRC+AC复合式结构加铺、直接加铺沥青面层以及碎石化加铺沥青层3种加铺方案,探讨现行规范的旧路加铺层设计方法,指出其存在的不足并提出改进措施。研究结果表明:CRC+AC加铺结构综合应力与普通混凝土板有很大不同,应针对这种结构确定更为明确的设计方法;直接加铺沥青层路面温度应力计算中可通过matlab软件回归延伸曲线,拓宽系数ζ'a图,加铺层设计引入满足防止荷载型及温度型反射裂缝要求的设计标准具有重要意义;碎石化沥青加铺层结构按半无限地基上的弹性层状体系理论方法设计得到的加铺层厚度初期实测弯沉代表值不能满足要求。

Combining with the reconstruction project of old cement concrete pavement of Xiangtan - Leiyang expressway, aiming at the 3 kinds of overlaying method commonly used in China at present, i. e. , CRC ＋ AC composite structure, paving asphalt surface directly and paving asphalt surface after rubblization, we discussed the design methods of overlaying on old pavement in current specifications, pointed out the flaws and put forward the improvement measures. The result shows that （ 1 ） the comprehensive stress of CRC ＋ AC composite structure is very different from the normal concrete structure, a more clear design method be determined for this kind of structure; （2） when calculating the temperature stress of directly paved asphalt pavement surface, the curve can be regressed and the figure of coefficient ∫^9a can be broadened through Matlab software, and to add design criterion about meeting the requirements of preventing the load reflective cracking and the temperature reflective cracking is of great significance; （2） the initial measured deflection value of the asphalt overlaying thickness after rubblization, which is designed by the theory of elastic layer system on semi-infinite foundation, cannot meet the requirements.