CFD自密实混凝土泵送性能模拟研究进展

Research Progress on CFD Self-compacting Concrete Pumping Performance Simulation

自密实混凝土(SCC)因其更好的可泵性被广泛用于混凝土泵送施工。由于成本高、耗时久、且结果可重复性较低,混凝土的泵送性能实验研究已逐渐被数值模拟研究所取代。本文综述了自密实混凝土泵送规律的近期研究成果。归纳了SCC在泵送管道流动过程中流速、压力损失等的变化规律。讨论了自密实混凝土在泵送过程中的流变规律。综述了自密实混凝土的流变模型在国内外的研究进程,分析了相关自密实混凝土模型的验证与改良及对一些自密实混凝土的流变性测试方法进行了统分。除对自密实混凝土的流变模型进行分析外,还描述了自密实混凝土在泵送前后的流变性能的差异。阐述了自密实混凝土微观状态下的DEM模型对坍落度试验的帮助,对目前较为认可的自密实混凝土泵送规律评估模型作了评述。结果表明自密实混凝土在泵送过程在CFD的模拟下节省了大量的人力物力,CFD自密实混凝土的泵送模拟发展还要再进一步完善,目前的流变模型能够准确地预测混凝土的泵送,但要想得到一个最佳的参数还需要大量验证试验去减小误差,CFD自密实混凝土的模拟还需要去不断完善。

Self-compacting concrete(SCC)is widely used in concrete pumping construction because of its better pumpability.The experimental study of pumping performance of concrete has been gradually replaced by numerical simulation research due to high cost,long time-consuming,and low reproducibility of results.The recent research results of self-compacting concrete pumping law were reviewed.The changes of flow velocity and pressure loss of SCC in the flow process of pumping pipeline were reviewed.The rheological law of selfcompacting concrete in the pumping process was discussed.The research process of rheological models of self-compacting concrete at home and abroad was reviewed,and the verification and improvement of related self-compacting concrete models were analyzed.The rheological test methods of some self-compacting concrete were divided.In addition to the analysis of the rheological model of self-compacting concrete,the difference in rheological properties of self-compacting concrete before and after pumping was also described.The DEM model in the microstate of self-compacting concrete in the slump test was described.The currently recognized evaluation model of self-compacting concrete pumping law was reviewed.The results show that self-compacting concrete in the pumping process in the CFD simulation saves a lot of manpower and material resources,CFD self-compacting concrete pumping simulation development to be further improved,the current rheological model can accurately predict the pumping of concrete,in order to obtain an optimal parameter also need to do a lot of verification tests to reduce the error,CFD self-compacting concrete simulation also needs to be continuously improved.