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Degradation Process and Life Span Estimation of Marine Concrete Structures

海洋混凝土结构的退化过程和寿命估算

基本信息

批准号：
09305032
负责人：
MIYAGAWA Toyoaki
金额：
$ 16.13万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09305032/
关键词：
Marine Concrete Structure Degradation Process Life Span Estimation Chrolide Corrosion High Performance Concrete Fiber Sheet Confined Concrete Construction Joint 海洋コンクリート繊維補強コンクリート

项目摘要

In this study, in making width volume ratio of confinement, existence of the CFRP sheet reinforcement, placing joint of the concrete including the salinity on the assumption of the macrocell corrosion, use of high workable concrete to be a factor, reinforcement corrosion of the RC flexural member in the salt water sprinkling accelarating environment was monitored. Results got are as follows.(a) The axial crack of width over 0.2mm and over several length has been all generated in specimens under salt water sprinkling at present. Though the difference of the crack by rho_s was not clear, in the CFRP sheet specimen, the crack width tended to be small. Both crack width and length of the high workable concrete specimen tended to be larger than the plain concrete(b) From corrosion loss rate of the bending span of the degraded specimen by AC corrosion monitor, more corrosion loss rate was observed in those specimens with confinement. Corrosion loss rate of the CFRP sheet reinforcement specimen comparatively small, It is due to the shielding of the salinity by the restraint of the crack in addition to the surface coating of the CFRP sheet.(c) Judging from aging of corrosion rate by the rectangular wave corrosion monitor, corrosion rate once increases on the dispersion from the axial cracking (around 97/7) and it tends to decrease afterwards. The increase is due to the crack propergation and the decrease is due to plugging of corrosion product.

在这项研究中，在制定约束宽度体积比、CFRP片材钢筋的存在、混凝土的浇筑缝（包括假设宏细胞腐蚀的盐度）、使用高和易性混凝土作为因素的过程中，监测了盐水喷洒加速环境中RC受弯构件的钢筋腐蚀。得到的结果如下：(a)目前盐水喷洒下的试件均已产生宽度超过0.2mm、长度超过数个的轴向裂纹。虽然rho_s裂纹的差异并不明显，但在CFRP片材样品中，裂纹宽度趋于较小。高和易性混凝土试件的裂缝宽度和长度都比素混凝土大。(b)从AC腐蚀监测仪对退化试件弯曲跨度的腐蚀损失率来看，在有约束的试件中观察到了更多的腐蚀损失率。 CFRP片材加固试件的腐蚀损失率相对较小，这是由于除了CFRP片材的表面涂层之外，裂纹的抑制对盐度的屏蔽。(c)从方波腐蚀监测仪的腐蚀速率时效来看，腐蚀速率在轴向裂纹的分散上(97/7左右)一度增大，之后呈下降趋势。增加是由于裂纹扩展，减少是由于腐蚀产物的堵塞。