| 種別 | Paper |
| 主題 | DEVELOPMENT OF HIGHLY DURABLE CONCRETE |
| 副題 | |
| 筆頭著者 | Masaharu SAKUTA |
| 連名者1 | Itoshi IZUMI |
| 連名者2 | Kyoichi TANAKA |
| 連名者3 | Masashi SUGIYAMA |
| 連名者4 | |
| 連名者5 | |
| キーワード | |
| 巻 | 9 |
| 号 | 2 |
| 先頭ページ | 645 |
| 末尾ページ | 650 |
| 年度 | 1987 |
| 要旨 | 1.INTRODUCTION In an ordinary atmospheric environment, corrosion of reinforcing steel in a concrete structure can occur when carbon dioxide permeates the concrete and the protective film of the steel is destroyed. Thus the rate of carbonation in concrete can be a significant factor in influencing the durability of the concrete structure. In urban areas, such as Tokyo or Osaka, sulfurous acid gas from the exhaust of automobiles is diffused in the atmosphere which greatly lowers the pH of rainwater falling in these areas. The penetration of this rainwater into concrete surfaces hastens the carbonation of the conerete and creates a problem. According to the results ofrecent measurements, the pH of rainwater in the Tokyo district is about 3.0. There have been many examples of exposed concrete surfaces being attacked by the strong acidity(1). Since carbonation of concrete results from the reaction between carbon dioxide and sulfurous acid in the atmosphere and calcium hydroxide in cement hydration products, the predominant concept in the past had been that this reaction was unavoidable. In view of this situation, the authors conducted studies principally on the use of chemical actions with the objective of providing a means of prolonging the lives of concrete structures by reducing the rate of carbonation. 5.CONCLUSIONS 1) The progress of carbonation and penetration of chloride ions are extremely slow in concrete containing the glycol ether derivative. 2) An amino alchohol derivative used for desulfurization and deoxidization during petroleum refining demonstrates an ability to absorb carbon dioxide and chloride ions even when added to mortar or concrete. 3) Carbonation and penetration of chloride ions in mortars containing these amino alchohol derivatives proceed at an extremely slow rate. 4) Through the life expectancy system for reinfroced concrete structure it was estimated that the life of the structure could be prolonged to several hundred years by utilization of these two derivatives. |
| PDFファイル名 | 009-01-2111.pdf |