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WATER PERMEABILITY OF REINFORCED CONCRETE MEMBER WITH NON-PENETRATION CRACK.

具有非贯穿裂缝的钢筋混凝土构件的透水率。

基本信息

批准号：
08650536
负责人：
OTSUKA Koji
金额：
$ 1.22万
依托单位：
TOHOKU GAKUIN UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08650536/
关键词：
Non-penetration crack Water permeability X-ray technique with contrast medium Diffusion coefficient Micro crack X線造影剤撮影法

项目摘要

Experiments were carried out to investigate the influence of the non-penetration crack formed in reinforced concrete member on the water permeability of the member. Beam type specimen which has one bending crack was used. The crack formation was controlled by a notch cut on the tension side of the beam at the center of the span. The beam was loaded by sustained loading. A ionized solution of x-ray contrast medium was injected into the crack and x-ray technique was used to inspect the penetrated area of the contrast medium in the concrete.As results of experiments, the following conclusion can be drawn :(1) By new x-ray technique, the penetrated area of contrast medium in concrete through a crack could measure.(2) When the contrast medium was injected into a crack by the pressure of 245 kPa, the pressure at the tip of the crack in the concrete was 225 kPa. The pressure loss was 8 %.When the contrast medium was injected into a crack by the pressure of 490kPa, the penetration area in the concrete was about two times of that obtained by the pressure of 245 kPa. It can be said that when the injection pressure of contrast medium is higher, the penetration speed of the contrast medium into the concrete through a crack becomes higher.(4) The penetration area of the contrast medium in the specimen which surface was sealed by coating material becames smaller than that of non-sealed specimen at the same injection test period. It can be said that when the concrete is more dry, the penetration speed becomes more high.(5) Results for permeability obtained by the x-ray technique using contrast medium were not the same value as that obtained by the direct splitting observation test using real water. Experiments were done to clear reasons whey the differences occurred. One of the reasons is supposed that the dynamic coefficient of viscosity of the contrast medium (1.06, density : 50 %) is higher than that of water (1.00).

通过试验研究了钢筋混凝土构件中非穿透性裂缝对构件透水性的影响。梁型试样，其中有一个弯曲裂纹。裂缝的形成是由在梁的受拉侧的跨度中心处切出的切口控制的。梁承受持续载荷。将电离的X射线造影剂溶液注入裂缝中，用X射线技术检测造影剂在混凝土中的渗透面积，实验结果表明：（1）采用新的X射线技术，可以测量造影剂在混凝土裂缝中的渗透面积; (2)当以245 kPa的压力将造影剂注入裂缝中时，混凝土中裂缝尖端处的压力为225 kPa。压力损失为8%，当压力为490 kPa时，造影剂在混凝土中的渗透面积约为压力为245 kPa时的两倍。可以说，当造影剂的注入压力越高时，造影剂通过裂缝进入混凝土的渗透速度越快。(4)在相同的注射时间内，经涂层材料封闭的试样中造影剂的渗透面积小于未封闭的试样。可以说，当混凝土更干燥时，渗透速度变得更高。(5)通过使用造影剂的X射线技术获得的渗透率结果与通过使用真实的水的直接分裂观察试验获得的渗透率值不同。并通过实验分析了产生差异的原因。原因之一是造影剂的动态粘度系数（1.06，密度：50%）高于水的动态粘度系数（1.00）。