EXPERIMENTAL STUDY ON DETERIORATION CHARACTERISTICS OF PARTIALLY REPAIRED RC SLABS UNDER FREEZING-THAWING AND FATIGUE COMBINED ACTION

摘要

As to bridge RC slabs in cold and snowy regions, the reduction of effective thickness due to frost damage of upper concrete affects load carrying capacity and fatigue durability. In Japan, actually, subsidence with upper frost damage has occasionally happened in RC slabs principally constructed in the late 1950s and 1960s, and it is predicted that the occurrence drastically increases in the near future. Accordingly, from the viewpoint of preventative maintenance to extend life of RC slabs, it is necessary to develop an upper repair method for cold and snowy environment. This study experimentally investigated the influence of upper repair on fatigue behaviour of RC slabs under frozen environment by using the experimental installation which can alternately apply both wheel running load repetitions and freezing-thawing cycles. From the experimental results, it was indicated that upper repair effect might not be sufficiently obtained in cold and snowy regions when using low durable materials against frozen environment, although the temporal improvement of fatigue durability was observed during frozen.