An investigation of the deterioration characteristics of concrete bridge decks with asphalt concrete in Korea

One of the most serious problems in maintaining and rehabilitating bridges is the deterioration of the asphalt concrete overlay, and subsequent deterioration of the deck concrete under the overlay. Although it is important from the perspective of the road managers to evaluate the exact status of the bridge deck thorough detailed examination, it still remains a difficult problem to determine the condition of the bridge deck under the overlay without coring samples. Accordingly, it is still a common and daily practice to examine the overlay surface and bottom of the bridge deck to evaluate its condition. Instead, this study collected cores from bridges with asphalt concrete in public service, which had manifested deterioration of the concrete deck. The study aimed to delineate the relationship between the deterioration status of the concrete bridge deck and the asphalt concrete overlay, waterproof layer, cover thickness of rebar, corrosion of rebar, and chloride contents in the concrete. The results of this investigation found that the deterioration of the concrete of the bridge deck was closely related to the functionality (performance) of the waterproof layer, and the deteriorated depth was significantly related to the average chloride content in the cover concrete of the top rebar.