碎石化后沥青加铺层应力对比分析

Stress Comparison Analysis of Asphalt Overlay on Rubblized PCC Slab

碎石化是一种旧水泥混凝土路面处治重要技术,它能降低建设成本,加快建设周期.文章基于有限元分析方法,首先对比分析了碎石化后加铺沥青面层和同厚度级配碎石层上加铺沥青面层的应力,结论认为碎石化后沥青加铺层底的拉应力要小于级配碎石的情况,证明碎石化后水泥混凝土板块优于级配碎石的力学性能;然后,通过改变碎石化层中两个主要分层的厚度和模量,分析不同的破碎程度对加铺层应力的影响,结论认为,碎石化下层厚度在10cm左右时,既能保证碎石化层仍然具有一定强度使沥青层底拉应力不至于过大,又能起到防止反射裂缝的作用.碎石化下层厚度不变时,加铺沥青层的受力状况随着碎石化下层模量的增大会稍有改善,拉应力、拉应变和弯沉都会有所减小,总体幅度在3%～9%之间.

Rubblization is important way to deal with old PCC slab, it can reduce cost and shorter constructing time. Based on finite element analysis, the paper compares the stress of asphalt overlay on mbblized PCC slab and graded gravel, which shows that stress on mbblized slab is less than on gravel. It is testified that the mbblized slab is better than graded gravel for base layer. By changing the height of two main parts of rubblized slab, it is found that 10 cm is the suitable height of under part, this height will keep the intensity of slab and avoid reflective crack at the same time. When the height of under layer fixed, the stress situation of asphalt overlay will be better if increasing the modulus of under part, tension stress, strain and deflection will all be reduced, and the range is between 3% and 9%.