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Study on Impact Tensile Strength of Concrete and Impact Falure of Reinforced Concrete Members

混凝土抗拉强度及钢筋混凝土构件冲击破坏研究

基本信息

批准号：
09650083
负责人：
DAIMARUYA Masashi
金额：
$ 2.11万
依托单位：
Muroran Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
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-09650083/
关键词：
Impact strength Impact breaking Impact tensile strength Concrete Stress Waves Reflected tensile stress waves Cumulative fracture probability コンクリート引張り応力波の集中破壊確率

项目摘要

(1) A newly developed measuring method for impact tensile strength of concrete has been proposed. The measurement method is based on the superposition and concentration of tensile stress waves reflected both from the free ends of a striking bar and a specimen bar. The impact tensile experiment is conducted by means of an air gun arrangement and a stress-bar technique. The setup consists of a striking bar shot out from an air gun and an input bar colliding collinearly with the striking bar on its one end. Another end of the input bar is in tight contact with one end of a specimen bar.(2) The measuring theory and the impact breaking behavior of concrete specimens were discussed on the base of the simple theory of stress waves propagated in a bar. They were verified by not only the experimental measurement but also the numerical simulation in axsymmertrical two demensional analysis using FEM code MARC.Reasonable agreements between the experimental measurement and calculated results were obtained.(3) The impact tensile experiment of some kinds of concrete specimens was performed, together with static strength tests such as direct tension, splitting tension, bending, and compression tests. The breaking position in a concrete specimen bar almost corresponded to the predicted position at which tensile stress concentration was initiated. It was found from the statistical analyses of the experimental data that the impact tensile strength of concretes was significantly influenced by loading-rates, and was found to be more than twice the static value.

(1)提出了一种新的混凝土冲击抗拉强度测试方法。该测量方法是基于冲击杆和试件自由端反射的拉伸应力波的叠加和集中。冲击拉伸实验是通过气枪装置和应力杆技术进行的。该装置包括从气枪射出的打击杆和与打击杆在其一端共线碰撞的输入杆。输入杆的另一端与试样杆的一端紧密接触。(2)从应力波在杆中传播的简单理论出发，讨论了混凝土试件的冲击破坏特性和测试原理。通过实验测量和有限元程序MARC轴对称二维分析的数值模拟，验证了理论分析的正确性，实验测量与计算结果吻合较好。(3)对几种混凝土试件进行了冲击拉伸试验，并进行了直拉、劈拉、弯曲、压缩等静强度试验。混凝土试件的断裂位置几乎与预测的拉应力集中开始的位置相对应。通过对试验数据的统计分析发现，混凝土的冲击抗拉强度受加载速率的影响很大，其值是静态值的2倍以上。