干混砂浆早期收缩变形性质研究及预测

Study and Prediction of Early Shrinkage Deformation Properties of Dry Mixed Mortar

试验研究了不同强度等级的干混砂浆早期失水率变化趋势及收缩变形的性质。试验结果表明:随着龄期的增长干混砂浆失水率不断提高,在增长到一定程度后基本保持不变;当龄期相同时,砂浆的失水率随水胶比的降低而减小。干混砂浆的早期干燥收缩值随龄期增加不断提高,前期变化速度较快,后期逐渐变缓;在龄期相同时,砂浆的干燥收缩值随水胶比的降低而降低。通过干燥收缩值预测模型对干混砂浆的收缩进行预测,模型计算结果与试验结果吻合程度较好。

The changing trend of early water loss rate and the properties of shrinkage deformation of dry mixed mortar with different strength grades were studied. The experimental results show that the water loss rate of dry mixed mortar increases with the increase of age, and remains unchanged after increasing to a certain extent, and decreases with the decrease of water-binder ratio when the age is the same. The early drying shrinkage value of dry mixed mortar increases with the increase of age, and the change rate of the early stage is faster, and that of the later stage gradually becomes slower, and the drying shrinkage value decreases with the decrease of water-binder ratio when the age is the same. Using prediction model of dry shrinkage value predict the shrinkage of dry mixed mortar and the calculated results of the model are in good agreement with the experimental results.