| 種別 | paper |
| 主題 | Influence of Construction Defects on Corrosion of Reinforcement |
| 副題 | |
| 筆頭著者 | Kamal Gad SHAROBIM （Hiroshima University） |
| 連名者1 | Ei-ichi TAZAWA （Hiroshima University） |
| 連名者2 | Hisashi MIYAMOTO （Hiroshima University） |
| 連名者3 | Tetsuya HIRONAKA （Hiroshima University） |
| 連名者4 | |
| 連名者5 | |
| キーワード | |
| 巻 | 11 |
| 号 | 2 |
| 先頭ページ | 703 |
| 末尾ページ | 708 |
| 年度 | 1989 |
| 要旨 | INTRODUCTION The corrosion of reinforcing steel in concrete had received increasing attention in recent years because of its wide spread occurrence in many types of structures and the high cost of repairs. Corrosion of steel,however,can occur if concrete is not adequate in quality,structure is not properly designed for the service environment,or the environment is not as anticipated or changed during the service life of the concrete. In reinforced concrete structures exposed to chlorides and subjected to intermittent wetting,the degree of protection against corrosion is determined primarily by design and construction practices. Permeability of concrete and depth of cover over the steel are some of the factors which control the onset and rate of corrosion. Other factors which play an important role in the corrosion of embedded steel are crack width, and implementation of measures designed specifically for corrosion protection. In this study,influences of construction practices such as consolidation,finishing practices,and arrangement of the reinforcing bars on corrosion of reinforcement were investigated. In addition,other defects such as cracking of concrete and missing of surface coating were discussed. CONCLUSION Based on the experiments carried out in this study,the following conclusions can be drawn:1)Equipotential measurement of half cell can predict the location of corrosion of reinforcing bars.2)The consolidation of concrete is one of the important factors by which the protection of reinforcing steel afforded by portland cement can be maximized.3)The presence of the annealed wire sticking out or located near concrete surface did not cause corrosion of reinforcement,hence it is suggested that these wires behaved as anode of corrosion cell while the reinforcing bars behaved as cathode. But,it would influence the appearance of concrete due to the occurrence of stains on concrete surface.4)There is no difference between corrosion of straight and bent bars if good protection is afforded by concrete.5)The presence of crack has a significant effect to accelerate the chloride corrosion of reinforcement especially those cracks parallel to the bars. Also,crack width has remarkable effect on corrosion areas.6)Concrete surface coating is one of protective method by which external chloride attack on reinforcement could be eliminated. Water repellent agent,as well as polymer coating can be regarded as one of the promising methods. |
| PDFファイル名 | 011-01-2118.pdf |