The Inspection of the Deterioration Factor and Examination of Durable Improvement Measures in the Upper Thickness Increasing Method for Slab Deck Reinforcement

Abstract

SynopsisIn NEXCO, upper thickness increasing method has been commonly adapted for slab deck reinforcement, it is, however, reported that pavement deterioration arisen from de-bonding of the interface between actually RC slab and reinforced concrete cast by this method within several years after the cast, it is, therefore, required to know the causes and its de-bond provisions. The study presents the specific causes obtained by investigation and small specimen tests, and the provision effects followed by the wheel running fatigue test. As the results, pavement deteriorations are strongly affected by the deterioration level of the actual slabs, the de-bonding commonly occurred at the interface between actual slabs and newly cast concrete. It is concluded that adequate provision is required to keep superior bonding strength, and then RC slab reinforcement have to be executed with consideration of deterioration level of the RC slab, are important.Keywords： slab deck, upper thickness increasing method, wheel running fatigue test, bond performance, de-bond provision, concrete crack