掺膨胀剂混凝土的限制膨胀率及限制干缩率的测定误差研究

Research on measurement error of limiting expansion rate and limiting drying shrinkage rate of concrete with expansion agent

按照GB/T 23439-2017《混凝土膨胀剂》附录B试验方法A测定掺膨胀剂混凝土的限制膨胀率及干缩率,和备选方法外径千分尺测定法相比,重复性测定误差率较大。通过三位试验员独立检测,单个试件重复三遍,附录B试验方法A是外径千分尺法平均差值的4.8倍,建议规范附录B试验方法A改用外径千分尺测量或增加外径千分尺法。

In accordance with GB/T 23439-2017 "Expansive agent for concrete", when using Method A of Appendix B to determine the limiting expansion rate and drying shrinkage rate of concrete mixed with expansion agent, it is found that the repeatability measurement error rate is much larger that of "outside micrometer method". Each test piece is repeated three times by three testers independently. The average error of Appendix B Method A is 4.8 times of that of the "outside micrometer method". It is recommended that Appendix B method A should be changed to "outside micrometer method" or the "outside micrometer method" should be added.