Title:
Deterioration of Reinforced Concrete
Wharf
Author(s):
Hiroshi Seki
Publication:
Concrete International
Volume:
3
Issue:
3
Appears on pages(s):
57-65
Keywords:
compressive strength; cores; corrosion
resistance; cover; marine atmospheres; mix propor-tioning;
piles; precast concrete; reinforced concrete;
reinforcing steels; salt water; seawater; sodium
DOI:
Date:
3/1/1981
Abstract:
The reinforced concrete peired wharf inspected is located at the western part of Japan (the northern part of Kyushu Island) and has been exposed to com-paritively mild natural and sea environments for 20 years. The structures are composed of reinforced concrete piles at the lower part and a reinforced con-crete beam-slab system at the upper part. In each reinforced concrete member there is a different eawater condition, construction methods (concrete cast in situ, precast concrete), quality of concrete, and cover of reinforcement. The deterioration was discussed based on the field observation and the laboratory testing results of core specimens. The experimental results consist of such items as concrete compressive strength, estimation of mix proportioning, neutralization of concrete, salt content accumulated in concrete, cover, and corrosion of rein-forcements. Concrete members exposed to the tidal zone tend to contain higher salt content compared to those exposed above the seawater or in the seawater. Reinforcement has no, or slight, corrosion which gives influence toward the damage of members, providing that concrete members are constructed under control. No deterioration is observed for precast standing crete members con Salt content decreases as the depth from the con crete surface increased, which corresponds the tendency of corrosion of reinforcement. The deeper the cover of reinforcement, the less the corrosion ol reinforcement. The upper members of the Wharf have to be designed in consideration of the impact factor or the excessive load such as the falling load must be prohibited at the unloading work of the cargos