Evaluation of remained fatigue life of expressway reinforced concrete slab strengthened by steel plate adhesion method

Abstract

Expressway reinforced concrete slabs designed according to the old design standards are fatigue critical members because of insufficient slab depth and reinforcements. Hanshin expressway, an urban expressway company in Osaka, Japan, has been retrofitting those reinforced concrete slabs by steel plate adhesion method to improve fatigue life since 1980’s. According to the most recent studies, internal horizontal cracks are still developing in the retrofitted reinforced concrete slabs; therefore, the remained fatigue life of retrofitted reinforced concrete slabs under current traffic loading is an urgent issue for maintaining expressway slabs in good condition. Under these circumstances, Hanshin expressway conducted the fatigue life study of retrofitted reinforced concrete slabs subjected to wheel loading test using extracted slab specimens from the expressway viaducts under service. According to the results of the wheel loading test with incremental wheel loading condition, the remained fatigue life of the retrofitted reinforced concrete slab with internal horizontal cracks is pretty short compared to the specimen without internal horizontal cracks. The paper will describe the detail results of the wheel loading tests.