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On Modified Pull-off Method Assessing Strength at Arbitrary Distance from Concrete Surface

改进的拉脱法评估距混凝土表面任意距离的强度

基本信息

批准号：
07555470
负责人：
TSUKINAGA Yoichi
金额：
$ 0.51万
依托单位：
Hachinohe Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555470/
关键词：
Non-destructive test Strength Deterioration Quality control Maintenance Pull-off method

项目摘要

(1) Establishment of test method1) Variations of pull-off tensile strength at each different distance from concrete surface were analyzed in the relation between maximum size of coarse aggregate and the size of core.2) Relations of the pull-off tensile strength versus the compressive strength, splitting tensile strength, pulse velocity, rebound number and pin penetration depth were examined.3) The accuracy of prediction of compressive strength by the pull-off tensile strength was made clear and compared to those by above non-destructive testing methods.(2) Application for evaluating strength in various kinds of concrete1) Characteristics of pull-off tensile strength at each different distance were investigated using specimens with a variety of mix proportion, age of test, cement type and moisture content.2) Pull-off tensile strength was available to evaluate the interface behavior such as bond strength between concrete and finishing materials.3) Pull-off tensile strength in the surface layr of concrete increased with the lowering of water cement ratio by using permeable form.(3) Application for assessing the deterioration1) Pull-off tensile strength was available to evaluate the degree of damage at each different distance due to freeze-thaw action.(4) Application for repair construction method1) Pull-off tensile strength was available to evaluate the required chipping depth of weakend portion, and the interface behavior such as bond strength after repairing.

(1)试验方法的建立1)分析了粗集料最大粒径与岩心粒径在离混凝土表面不同距离处拉脱抗拉强度的变化规律。2)考察了拉脱抗拉强度与抗压强度、劈裂抗拉强度、脉冲速度、回弹次数、销入深度的关系。3)明确了拉脱抗拉强度预测抗压强度的准确性，并与上述无损检测方法进行了比较。(2)在各种混凝土强度评定中的应用1)采用不同配合比、试验龄期、水泥类型和含水率的试件，研究了不同距离下的拉拔抗拉强度特性。2)拉脱抗拉强度可用于评价混凝土与饰面材料之间的粘结强度等界面行为。3)采用透水形式，随着水灰比的降低，混凝土表层拉脱抗拉强度增大。(3)评价劣化程度的应用1)拉脱抗拉强度可用于评价冻融作用在不同距离下的损伤程度。(4)修复施工方法的应用1)拉脱抗拉强度可用于评估弱端部分所需的切分深度，以及修复后的粘结强度等界面行为。