Investigation on the effect of various factors on the rate of corrosion of reinforcing bar in concrete and estimation of the life of RC buildings

Research Project

Project/Area Number	21560579
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Building structures/materials
Research Institution	Utsunomiya University
Principal Investigator	MASUDA Yoshihiro 宇都宮大学, 工学研究科, 教授 (30272214)
Project Period (FY)	2009 – 2011
Project Status	Completed (Fiscal Year 2011)
Budget Amount *help	¥5,070,000 (Direct Cost: ¥3,900,000、Indirect Cost: ¥1,170,000) Fiscal Year 2011: ¥520,000 (Direct Cost: ¥400,000、Indirect Cost: ¥120,000) Fiscal Year 2010: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000) Fiscal Year 2009: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000)
Keywords	腐食速度 / 質量減少 / 塩分量 / 水セメント比 / かぶり厚さ / 鉄筋コンクリート / 鉄筋腐食 / 含水率 / 塩化物量
Research Abstract	The long term outdoor exposure test on the rate of corrosion of reinforcing bar in concrete which contains chloride ion. The factor of experiment are sodium chloride content(0～1.0%/sand), water-cement ratio(50～65%), and thickness of concrete cover(15～40mm). It is conclude as follows. The corrosion loss of reinforcing bar in long term outdoor exposure test increases in proportion to square root of exposure period. Rate of corrosion of reinforcing bar decrease with increasing thickness of concrete cover in sodium chloride content(0～0.3%/sand). The estimation equation of the rate of corrosion of sodium chloride content are proposed by thickness of concrete cover and water cement ratio.