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Development of Pullout Test Method and Proposal for Quality Assurance System of In-place Concrete Strength

现浇混凝土强度拉拔试验方法的研制及质量保证体系的建议

基本信息

批准号：
60850107
负责人：
MORITA Shiro
金额：
$ 6.14万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1985
资助国家：
日本
起止时间：
1985 至 1987
项目状态：
已结题

项目摘要

With the increasing use of high-strength concrete for cast in-situ concrete structures, the prediction of reliable in-place concrete strength becomes more important at every critical construction operation. The first objective of this project is to develope the pullout method of in-place strength evaluation of concrete. The second objective is to propose an application method of the pullout test for the quality assurance of in-place concrete. Summary of the main results of this project are as follows:1. On the basis of the studies by earlier researchers on the pullout method, the appropriate size and the test equipment for testing building structures could be developed from the viewpoints of reliablity, simplicity, cost performance and time effectiveness.2. The test method for examining the strength distribuition alog the axis perpendicular to a surface could be developed.3. The developed pullout method was applied to the construction site of a thirty six story building structure, to which high strength concrete was used. The strength assurance method applied could give reliable records of in-place concrete strength of the structure.4. The pullout method could be successfully applied for the evaluation of eight hour strength of steam cured precast pannels.5. It was shown from laboratory tests that the average value of the coefficients of variation were about 3% for cylinder test, 6% for core tests and 10% for pullout tests.6. From the non-linear finite element analysis, the mechanism of failure of the pullout method was clarified.7. A quality assurance system of in-place concrete was proposed in which the pullout method played an important role.

随着高强混凝土在现浇混凝土结构中的应用越来越广泛，在每一个关键的施工操作中，可靠的现浇混凝土强度的预测变得更加重要。本计画的第一个目标是发展混凝土强度现场评估的拔出法。第二个目的是提出一个应用方法的拔出试验的质量保证，在现场混凝土。本项目的主要成果总结如下：1.在前人对拔出法研究的基础上，从可靠性、简便性、性价比和时效性的角度出发，可以开发出适合于建筑结构测试的尺寸和测试设备.建立了检测垂直于表面的轴向强度分布的试验方法.将该方法应用于一座36层高强混凝土结构的施工现场。所采用的强度保证方法能够可靠地记录结构的现浇混凝土强度.拔出法可以成功地应用于蒸养预制板的八小时强度评估.室内试验结果表明，圆筒试验变异系数平均值约为3%，岩芯试验变异系数平均值约为6%，拉拔试验变异系数平均值约为10%.通过非线性有限元分析，阐明了拔出法的破坏机理.提出了以拔出法为核心的现浇混凝土质量保证体系。