机制砂预拌砂浆开放时间的影响因素分析

Factors Analysis on Operation Time of Manufactured Sand Mortar

为解决机制砂预拌砂浆开放时间控制不精确的问题,本实验研究了机制砂特性、外加剂、粉煤灰以及温度对机制砂预拌砂浆开放时间的影响。结果表明:合理的砂级配以及石粉含量能够降低砂浆标准稠度用水量以及外加剂掺量。HPMC、引气剂以及粉煤灰的掺入可以显著提高砂浆的初始稠度。而缓凝剂与温度主要影响预拌砂浆的稠度下降速度,较高的环境温度会显著的减少砂浆开放时间。砂浆稠度变化方程能够帮助判断预拌砂浆早期稠度变化过程,可用于计算预拌砂浆的开放时间。

In order to accurately control the operation time of manufactured sand mortar,the effect of sand properties,admixture,fly ash and the temperature of sand mortar operation time was studied in this experiment.The results show that the reasonable graded sand and stone powder content can reduce water and admixture consumption of mortar.HPMC,air entraining agent and fly ash can improve the initial consistency of mortar.The decline rate of consistency mainly affected by the retarder and temperature,higher temperature can significantly reduce mortar＇s operation time.Mortar consistency change equation can be applied to determine the consistency of the early changes of ready mixed mortar,it can be used for operation time calculation of mortar.