| 種別 | paper |
| 主題 | Application of Polymer Dispersions as Primers for Troweling Works |
| 副題 | |
| 筆頭著者 | Yoshihiko OHAMA （Nihon University） |
| 連名者1 | Katsunori DEMURA （Nihon University） |
| 連名者2 | Sanjay Narendra PAREEK （Nihon University） |
| 連名者3 | |
| 連名者4 | |
| 連名者5 | |
| キーワード | |
| 巻 | 11 |
| 号 | 2 |
| 先頭ページ | 697 |
| 末尾ページ | 702 |
| 年度 | 1989 |
| 要旨 | INTRODUCTION Ordinary cement mortar,one of the most common construction materials has widely been used as a finishing or repairing material. Thus it is extremely important to maintain the certain adhesion or bond of fresh mortar to concrete or mortar surfaces in the construction industry. For the purpose of obtaining the certain adhesion,polymer dispersions (latexes or emulsions) have been employed as primers or bonding agents for the concrete or mortar surfaces for the past 20 years. In the United States,an ASTM Standard for the quality requirements of such polymer dispersions has already been published. However, the effectiveness of the polymer dispersions as adhesion aids has differently been evaluated by their manufacturers and users till now. The mechanism of improving the adhesion between fresh mortar and concrete or mortar substrates by polymer dispersion coatings is generally considered as follows:(1)The prevention of dry-out due to the inhibition of water absorption into the concrete or mortar substrates and of air bubbles releasing with water absorption from the substrates by the effects of the formed polymer films.(2)The reinforcement of the bonding surfaces due to the penetration of the polymer dispersions into the surface layers of the concrete or mortar substrates.(3)The formation of chemical bonds and micromechanical interlocking mechanisms through the formed polymer films at the adhesive interfaces.(4)Relaxation of stresses occurring at the adhesive interfaces by the formed polymer films. The paper deals with a basic study on an improvement in the adhesion of fresh mortar to mortar substrates with polymer dispersion coatings. Mortar substrates are coated with three types of polymer dispersions as primers with various polymer solid contents at various coverage rates. After various open times,the polymer dispersion coated mortar substrates were bonded or placed with fresh mortar,and the coated mortar substrates bonded with the fresh mortar were tested for adhesion in tension. The effects of the open time,polymer solid content and coverage rate on the adhesion in tension are discussed. CONCLUSIONS (1)The adhesion in tension of fresh mortar to polymer dispersion coated mortar substrates is increased to about 2 to 3 times that to uncoated mortar substrates.(2)A suitable open time is necessary for the good adhesion of fresh mortar to polymer dispersion coated mortar substrates.(3)The effects of the polymer solid content and coverage rate of polymer dispersions on the adhesion in tension of fresh mortar to polymer dispersion coated mortar substrates are not clarified in this study. |
| PDFファイル名 | 011-01-2117.pdf |