Construction of Real Mesostructure Model and Numerical Analysis of Uniaxial Compression for Fiber Reinforced Permeable Concrete

In this paper, fiber reinforced permeable concrete (FRPC) is considered to consist of aggregate, mortar (containing polyacrylonitrile fibers inside), interface transition zone (ITZ) and pores from mesoscopic perspective. Trainable Weka Segmentation (TWS) segmentation algorithm and morphological processing were applied on Computer Tomography (CT) images to extract the components of FRPC to establish a 3D real mesostructure model with realistic spatial structure. The 3D model was used to carry out qualitative numerical simulation of uniaxial compression process of FRPC specimen. Stress, displacement, macroscopic and mesoscopic cracks of the model were analyzed to reveal the fracture process of FRPC. The results showed that the fracture of the model is mainly caused by stress concentration and large deformation at local weak positions. The macroscopic fracturing process of the model consists of three stages: (i) crack initiation period, (ii) slow development period, (iii) rapid propagation period model fracture period. The fracturing process in mesoscopic componnets can be concluded as a progressive failure that consists of three stages: (i) pores and ITZ cracking period, (ii) cement mortar cracking period, (iii) aggregates fracture and structural failure period. The accuracy and reliability of the numerical model construction method was verified by comparing the crack distribution pattern of the model and the destruction characteristics of the specimen in physical uniaxial compression experiment.