Study on Water Proofing to Increase Durability for Fatigue of Reinforced Concrete Slabs of Highway Bridges

在日本，大约自1970年以来，钢筋混凝土板的恶化一直是一个严重的问题。这种恶化可以解释为车辆重载引起的疲劳失效。此外，雨水渗透到楼板的裂缝中，增加了破坏的速度。为了提高楼板的耐久性，在沥青路面和混凝土楼板之间铺设防水层似乎是非常有效的。然而，现有的防水材料都是为建筑屋面开发的，不进行疲劳耐久性校核，很难应用于桥板。研究人员在车轮运行载荷下进行了一系列疲劳试验，以找到合适的防水材料。疲劳试验方法是研究公路桥梁板在车轮荷载作用下发生劣化的一种新颖方法。对环氧树脂、合成沥青片材、丙烯酸树脂、丙烯酸胶树脂和丙烯酸树脂混凝土等5种材料进行了研究。从材料环境试验来看，它们似乎是适用的。通过疲劳试验，研究人员可以推荐预制沥青板和Akuril树脂组用于楼板防水。

In Japan, deterioration of reinforced concrete slabs have been serious problem since about 1970. The deterioration can be explained as a fatigue failure due to heavy vehicle loads. Furthermore, penetration of rain water into cracks occurring in the slabs is increasing the rate of damages. To increase the durability of slabs, it seems to by very effective to put water proofing between pavement of asphalt and concrete slab. However, the existing water Proofing materials were developed for roof of buildings and it is difficult to apply them to the bridge slabs without check of fatigue durability. The researchers have carried out a series of fatigue tests under a running wheel load to find out suitable water proofings. The fatigue testing method is an original method to investigate slabs of highway bridges because the slabs occur deterioration due to running wheel loads. Five materials such as Epoxy resins, Fabricated asphalt sheet, Acrylic resins, Acrylic-gum resins, and Acrylic resin concrete were examined. They seem to be applicable from the material environmental tests. From the fatigue tests, the researcher can recommend the Fabricated asphalt sheet and Akuril resin troups for the water proofing on slabs.