| 種別 | Paper |
| 主題 | ADHESION OF POLYMER-MODIFIED MORTARS TO FORCING BARS |
| 副題 | |
| 筆頭著者 | Sanjay Narendra PAREEK（Nihon University） |
| 連名者1 | Yoshihiko OHAMA（Nihon University） |
| 連名者2 | Katsunori DEMURA（Nihon University） |
| 連名者3 | |
| 連名者4 | |
| 連名者5 | |
| キーワード | |
| 巻 | 13 |
| 号 | 1 |
| 先頭ページ | 957 |
| 末尾ページ | 962 |
| 年度 | 1991 |
| 要旨 | INTRODUCTION In recent years, the rapid deterioration of reinforced concrete structures has become a serious problem in the world, and various repair and renovation techniques for damaged reinforced concrete structures have actively been developed. Polymer-modified mortars are widely used as repairing materials because of their superior durability and good adhesion to concrete surfaces. However, the bond or adhesion of the polymer-modified mortars to reinforcing bars remains doubtful, because it is considered that the bond or adhesion depends on the type of polymer dispersion and the polymer-cement ratio. In this research work, polymer-modified mortars using cationic, anionic and nonionic polymer dispersions are prepared with various polymer-cement ratios, and tested for bond strength through the pull-out of vertically embedded reinforcing bars in the mortars. Since the polymer-modified mortars are found to reduce their bond strength to some extent after water immersion, the retention of the bond strength of the polymer-modified mortars to the reinforcing bars through water immersion is also examined. Moreover, the bond or adhesion mechanism of the polymer-modified mortars to the reinforcing bars has been proposed with the help of model diagrams. CONCLUSIONS (1) The bond strength of cationic polymer-modified mortars to reinforcing bars is much higher than that of unmodified, anionic and nonionic polymer-modified mortars. In particular, the bond strength of the cationic polymer-modified mortars increases considerably with raising polymer-cement ratio. In general, the type of electrical charge on the polymer particles in the polymer dispersions used and the polymer-cement ratio are the most dominant factors in the bonding of the polymer-modified mortars to the reinforcing bars. (2) Generally, the retention of the bond strength of polymer-modified mortars to reinforcing bars after water immersion is 60 to 80%, and is almost the same as that of unmodified mortar. (3) The bond or adhesion between polymer-modified mortars and reinforcing bars is the result of presence of elctrochemically active polymer-cement co-matrixes at the interfaces which helps to relax stresses during loading and retards the friction-controlled slip of the reinforcing bars. |
| PDFファイル名 | 013-01-1166.pdf |