Study on the Evaluation of Influence of Creep on Autogenous Shrinkage Stress

蠕变对自收缩应力影响的评价研究

基本信息

批准号：
09650506
负责人：
MORIMOTO Hiroaki
金额：
$ 1.28万
依托单位：
Gifu University
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 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650506/
关键词：
High strength concrete Autogenous shrinkage Young age Compressive creep Tensile creep Variable stress Method of superposition Effective Young's modulus 自己収縮

项目摘要

The following concepts were clarified on the compressive and tensile creep, the evaluation method of creep under changing stress and the calculation method of autogenous shrinkage stress of high strength concrete in early ages.1. Creep is proportion to a stress to the extent of 40 % of stress-strength ratio, at least.2. A significant difference is not recognized with compressive and tensile creep.3. Creep characterisitic changes greatly near by the age of 1 or 2 days, and the change is small after the age of 3 days.4. Basic creep function for high strength concrete in early age can be given by the product of final creep value and creep progress function.5. Creep value right after the stress reversal estimated by the method of superposition is grater than the measured a little, yet the estimated value generally agree well with the measured value.6. There are no remarkable differences between the estimated values by the time hardning rule and the strain hardning rule, and the estimated vales are fairly small compared with the measured value, especially right after the stress reversal.7. The time hardining rule and the time hardning rule require some appropriate correction considering the softning due to the stress reversal.8. The autogenous shrinkage stress of 1.5N/mmィイD12ィエD1 at the age of 7 days and 2.2N/mmィイD12ィエD1 at the age of 60 days were measured by using JCI method in high strength concrete having water-cement ratio of 30%.9. The autogenous shrinkage stress can be estimated by the increment method using the effective Young's modulus calculated from measured creep coefficient of high strength concrete having water-cement ratio of 30%.10. The Young's modulus reduction coefficient for calculation of autogenous shirinkage stress is a little smaller than that for thermal stress calculation

在早期驴子中，高强度混凝土的自体收缩应力的压缩和拉伸蠕变均与应力的范围相称有意义的压缩和拉伸蠕变均未达到1或2天的年龄。在通过叠加方法估计的应力之后，测得的稍微稍微稍微与tomasured值相关的值。6。 Hardning规则和估计的阀门与测量值相当紧张，尤其是在压力逆转之后。 7天的1.5N/mm II D12 Yi D1和60天的2.2n/mm II D1是高强度混凝土的JCI方法，可以通过水泥收缩率30％估算。使用测得的蠕变系数的缩放系数为.10的蠕变系数的增量。