高石粉含量灰岩人工砂混凝土的收缩及其预测模型

摘要

In the process of artificial sand preparation,a certain high amount of stone powder will inevitably be produced.These stone powders have important influence on properties of concrete.The shrinkage charac-teristics of 7 artificial sand concrete mixtures with different stone powder contents (12%,15%,18%,20%, 22%,25% and 28%)are studied.According to the test results,4 commonly used concrete shrinkage predic-tion models are evaluated,namely model of China Academy of Building (1986),CEB-FIP model (1990),GZ 1993 model and GL 2000 model.The results show that the shrinkage mode recommended from GZ 1993 and GL 2000 agreed well with the measured results from the specimens.On this basis,the influence coefficient of stone powder is introduced to revise the GZ 1993 and GL 2000 models respectively.A shrinkage prediction model of artificial aggregate concrete with high stone content is established.%人工砂制备过程中不可避免地会产生大量的石粉,这些石粉会对混凝土的性能产生重要影响.试验研究了7种石粉含量(12%、15%、18%、20%、22%、25%、28%)的人工砂混凝土的收缩性能,根据试验结果评估了目前4种常用的混凝土收缩预测模型,即中国建科院模型(1986)、CEB-FIP模型(1990)、GZ 1993模型以及 GL 2000模型的适用性.结果表明,GZ 1993和 GL 2000收缩模型的预测结果与试验结果较为吻合.在此基础上,引入石粉影响系数分别对GZ 1993和GL 2000模型进行修正,建立了高石粉含量人工砂混凝土的收缩预测模型.