Study on the non-linear deformation and failure characteristics of EPS concrete based on CT-scanned structure modelling and cloud computing

To understand the complex deformation features and failure mechanisms of expanded poly-styrene (EPS) concrete and reveal the composite effect of expanded polystyrene beads and polypropylene fibers, a series of experiments were conducted on the poured EPS concrete spec-imens. Meanwhile, a cloud computing system for 3D realistic failure process analysis (RFPA3D) was established to model the fine failure process of a real concrete structure. The micromor-phology of the EPS concrete specimens was obtained via CT scanning and further processed using digital image processing technology. The Otsu algorithm was applied to automatically recognize the segmentation thresholds of each partition image and a procedure for CT image processing was designed to automatically realize digital image segmentation and merging. Then, the numerical models reflecting the microstructures of the EPS concrete specimens were built using the pro-cessed digital images and a series of 3D numerical simulations were performed using cloud-computing-based RFPA3D. The results show that for concrete with low EPS volume fracture, the non-smooth convex-step-shaped failure morphology, which is a typical brittle fracture char-acteristic, appears. In contrast, ductile fracture occurs for concrete with a high EPS volume fracture. Simultaneously, the addition of polypropylene fibers of a certain length can effectively prevent the formation and expansion of new cracks in the cement matrix. In addition, the peak strength of concrete increases with an increase in homogeneity while the residual strength generally decreases with an increase in homogeneity. Moreover, a more heterogeneous material presented more acoustic emission precursors before macro fracture. All these achievements greatly improve our knowledge of the design, construction, and maintenance of EPS concrete in civil engineering.

Automated summary

This study conducted experiments and numerical simulations to understand the complex deformation features and failure mechanisms of expanded polystyrene (EPS) concrete and investigate the composite effect of polypropylene fibers. The results showed that concrete with low EPS volume fracture exhibited typical brittle fracture, while concrete with high EPS volume fracture displayed ductile fracture. The addition of polypropylene fibers effectively prevented the formation and expansion of new cracks and increased the peak strength of the concrete.