混凝土膨胀剂限制膨胀率试验方法在应用中值得注意的几个问题

Several remarkable issues in the restrained expansion ratio test of expansive agents for concrete

在依据《混凝土膨胀剂》GB23439-2009检测膨胀剂限制膨胀率时,影响检测结果准确性的因素比较多,本文就其中几个关键性因素做了分析,指出养护环境湿度的准确测定取决于干湿球温度计的正确使用及选择合适的校准方式;保证恒温恒湿室样品区域湿度稳定的有效措施是对区域进行简单的遮挡和围护;应注意恒温恒湿箱箱体内的风速对试件限制膨胀率值的影响,建议在以后修订标准中给出试件表面风速的上限值;即使在标准规定的养护温度范围内,试件的温度线膨胀系数对检测结果依然有很大影响;保证长度测量值稳定应注意的几个方面。

There are some factors that impact the testing accuracy in the restrained expansion ratio test of concrete expansive agents in accordance with the national standard GB23439-2009.This study investigated several important factors, and finds out that the accurate test of humidity in the curing environment depends on the correct use and calibration of the wet and dry bulb thermometer;the effective measures to guarantee the stable humidity in the constant temperature and humidity chamber is to provide the covering and enclosure for the chamber;the wind speed in the constant temperature and humidity chamber has effect on the restrained expansion ratio of samples,and the upper range value of surface wind speed of samples should be given in the future revision of the national standard;the thermally linear expansion ratio of samples has a big effect on the testing result even within the stipulated curing temperature range by the standard;the several notable aspects to guarantee the stable measure value of length.