Studies on Improvement of Concrete Durability by Surface Treatement

Research Project

Project/Area Number	60850092
Research Category	Grant-in-Aid for Developmental Scientific Research
Allocation Type	Single-year Grants
Research Field	コンクリート工学・土木材料・施工
Research Institution	Institute of Industrial Science, University of Tokyo
Principal Investigator	KOBAYASHI Kazusuke Institute of Industrial Science, University of Tokyo, 生産技術研究所, 教授 (10013096)
Co-Investigator(Kenkyū-buntansha)	MASAKI Daimon Faculty of Engineering, Tokyo Institute of Technology, 工学部, 助教授 (10016579) OOHAMA Yoshihiko Faculty of Engineering, Nippon University, 工学部, 教授 (40102579)
Project Period (FY)	1985 – 1986
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥5,500,000 (Direct Cost: ¥5,500,000) Fiscal Year 1986: ¥1,500,000 (Direct Cost: ¥1,500,000) Fiscal Year 1985: ¥4,000,000 (Direct Cost: ¥4,000,000)
Keywords	Durability of Concrete / Corrosion of Reinforcing Steel / Polymers / コンクリート表層部 / 含浸 / セメント硬化体の細孔構造
Research Abstract	This research was carried out with the purpose of establishing an effective technique for long-term corrosion protection of steel in concrete taking advantage of the fact that concrete is a porous material and causing an organic substance to impregnate the surface layer portion of the concrete to form a layer impervious to corrosive elements such as chloride ions and oxygen. The contents of the research done are as follows : 1) As a result of investigating the relationship between mass transfer and constitutional structure with the surface portion of concrete which is the part that allows the impregnating material to penetrate and which at the same time is also the part serving as the route for ingress of corrosive elemwnts, it was revealed that mass transfer through this part depends greatly on microcracks produced by shrinkage rather than on pores. 2) In proceeding with development of an impregnating materials suited for the purpose of this research the performance of various materials including those commercially available were evaluated, and since as a result it was found that paint-on penetration type impregnating materials of alkyl alkoxysilane base had exellent chloride shielding effects, research was done to develope a normal-temparature reacting and hardening impregnating material of this type. 3) A study was made of a technique to quantitatively evaluate the degree of impregnation of impregnating material to the surface layer of concrete and a high-freguency resistance measuring apparatus for obtaining the degree of impregnation by impregnating material by non-destructive tests was manufactured on a trial basis.