The Research Of Discrete Element Method Simulation For Particle Packing-based Cementitious Materials

Cementitious material has been used widely as construction material. The ecologization of cementitious material is one of the most popular research areas in material. One of the ecological approaches is particle packing model design method. This thesis was based on Compressible Packing Model(CPM), and discrete element modelling(DEM) was used to investigate the property of particle packing, the agglomerating effects of fine particles and the flowability of concrete mixtures. The main works are as follows:Firstly, the particle packing density based on CPM was researched. Main works including: 1) The influence of particle shape upon packing density was studied; 2) The influence of vibration process upon packing density was analyzed; 3) Calibration of the model with binary date; 4) Modified model was used to assess ternary particle mixtures.Secondly, the packing state of agglomerating fine particle was researched and the CPM model was modified. Main works including: 1) The interaction function of fine particle was proposed. 2) The contact model in DEM was defined. 3) The CPM model combined with interaction and compaction was developed.Finally, the fresh concrete composed of particles was simulated. The DEM model of fresh concrete was proposed. The manual and automated mixing progress, the flow test and the pumping procedure of concrete were simulated.Above all, the thesis was based on CPM model, and DEM was used to study the property of particle packing, the agglomerating effects of fine particles and the flowability of concrete mixtures. In addition, it provides a practicable method for those relevant particle system research.