EVALUATION OF STIFFENING EFFECT AND FATIGUE RESISTANCE OF ADHESIVE-APPLIED BOTTOM SURFACE THICKNESS INCREASE RC SLAB WITH CFRP GRID

In bottom surface thickness increase reinforcement method applied tension members with reinforcing bar of Road bridge reinforced cocrete (RC) slabs. But, the crossing part of reinforcing bar has thickness diamater of 2 times, there are concern cover concrete thickens and the dead load enlargement. Therefore, this study evaluates in two case of bottom surface thickness increase reinforcing method of stiffening effects and fatigue resistance, the reinforcement substitute carbon fiber reinforced polymer (CFRP) grid for reinforcing bar reinforcing method and applied adhesive to thickness increase interface. The reinforcing effects were evaluated as fatigue resistance of the RC slabs examined under the load carrying wheel tracking machine. As the results the re-bar applied specimen by 3.1 times, the CFRP grid applied specimen by 3.8 times, and applied-adhesive reinforcing specimens prove stiffening effect by 16.4 and 19.2 times, than compared to standard specimen. This study was evaluated by number of equivalent cycles. Accordingly, it is prove that CFRP grid and applied adhesive has stiffening effected and fatigue resistance. From the above, CFRP grid and applied adhesive reinforcing method is practical method.RC床版の下面増厚補強法の引張補強材には鉄筋が用いられている。しかし、鉄筋の交差部は鉄筋径の2倍となり、かぶりを考慮すると増厚部が厚くなり、死荷重の増大が懸念されている。そこで本研究は引張補強材にCFRP格子筋を用いた補強法、増厚界面に接着剤を塗布し、CFRP格子筋を用いた補強法の補強効果および耐疲労性を評価した。その結果、RC床版供試体に比してワイヤーメッシュを用いた供試体は3.1倍、CFRP格子筋を用いた補強法は3.8倍、接着剤を塗布した補強においてはそれぞれ16.4倍、19.2倍の補強効果が得られた。よって、CFRP格子筋および接着剤を塗布する補強法は耐疲労性が評価され、実用的である。