Numerical simulation of cost-effective green high-ductility engineered cementitious composites based on meso-scale particle flow model

Abstract

To promote the sustainable development of building materials and reduce their cost, the cost-effective green high-ductility engineered cementitious composites (ECC) was developed by using domestic low-cost polyvinyl alcohol (PVA) fibers, ordinary river sand and high-volume incorporation of fly ash (FA) and silica fume (SF). The effects of different river sand particle sizes, sand-binder ratio and water-binder ratio on the bending and tensile properties of ECC were studied. Meanwhile, the meso-scale particle flow model based on discrete element method (DEM) is used to simulate the multi cracking behavior of ECC under four-point bending load and uniaxial tensile load. This is a new application of particle flow model in ECC. Moreover, the distribution characteristics and temporal-spatial evolution law of the of micro-cracks in ECC are simulated by using the DEM. Further on, the distribution of the force chain of the ECC are analyzed, and the visualization of the force chain under bending and tensile load is realized for the first time. Simulation results show that the multi cracking behavior mainly occurs in the pure bending section under four-point bending load, and the micro-cracks under uniaxial tensile load is uniformly distributed on the sample surface. Meanwhile, the unstable fracture of the strong force chain arch is the essential reason for the ECC failure. The curves and failure patterns obtained by simulation is compared to experimental results to verify the effectiveness of the numerical model.