Studies on Methods to Assess the Quality of the Surface Layer of Concrete

混凝土表层质量评价方法的研究

基本信息

批准号：
02555107
负责人：
SHOYA Masami
金额：
$ 3.07万
依托单位：
Hachinohe Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1992
项目状态：
已结题

项目摘要

1. Establishment of test methods and assessment of concrete quality.The convenient assessing methods of concrete quality were introduced, which were applicable on site and composed of non-destructive tests on surface strength and surface durability. Two kinds of pull-off and pull-out strength tests for the former strength and three kinds of permeability tests applying Figg's method for the latter durability were proposed.2. Influencing factor on test results.Two strength tests and there permeability tests well reflected the change of concrete quality due to the change of water cement ratio, the age and so on. However, permeability values required the correction o f moisture content, and the maximum size of coarse aggregates greatly affected the estimated strength. The coefficients of variation were up-most 20% for the former strength tests and 30% for the latter permeability tests.3. Application of proposed tests for quality control and maintenanceTwo strength tests are available to estimate the structural strength of concrete as well as the change of near surface strength due to freeze-thaw action, carbonation and other causes. In special, the propose d pull-off strength test is promising for estimating the strength in a aribitary depth. Three permeability test data were closely related to the porosity change of concrete and also available to judge the change of surface concrete quality. However, the more detailed study was needed to set up the threshold values determining the deterioration of concrete.

1。建立测试方法和混凝土质量的评估。引入了便捷的混凝土质量评估方法，这些方法适用于现场，并由表面强度和表面耐用性的非破坏性测试组成。提出了两种针对以前强度的推出和拉出强度测试，并提出了三种应用FIGG方法的渗透率测试，以用于后一种耐用性。2。影响因素对测试结果的影响。两次强度测试和渗透性测试很好地反映了由于水泥比的变化，年龄等的变化，混凝土质量的变化。但是，渗透率值需要对水分含量进行校正，而粗骨料的最大尺寸极大地影响了估计的强度。以前的强度测试的变异系数最高为20％，而后者的渗透率测试为30％。3。可以使用拟议的测试用于质量控制和维护强度测试，以估算混凝土的结构强度以及由于冻融作用，碳酸化和其他原因而引起的近表面强度的变化。在特殊情况下，提出的D推出强度测试有望估计贵族深度的强度。三个渗透性测试数据与混凝土的孔隙率变化密切相关，也可用于判断表面混凝土质量的变化。但是，需要更详细的研究来设置确定混凝土恶化的阈值。