Drying shrinkage crack simulation and meso-scale model of concrete repair systems. (30th June 2020)

• Record Type: Journal Article
• Authors: Zhou, Yuliang; Jin, Hao; Wang, Binglong
• Is Part Of: Construction & building materials. Volume 247(2020)
• Publication Date: 2020-06-30
• Subjects: Concrete repair systems -- Meso-scale -- Cohesive element -- Bonding strength -- Rough interface; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.118566
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: A meso-scale model of concrete repair systems similar to reality was presented. The zero-thickness cohesive element was applied to simulate the shrinkage crack. Model parameters were verified by comparison with the Li's experiment. Effect of aggregate, interface roughness and strength on shrinkage crack was studied. Abstract: Repairing materials and interfacial bonding quality are the two crucial factors that affect the shrinkage performance of concrete repair systems. The objective of this paper is to provide a fine meso-scale modelling method of concrete repair systems and to get a better understanding of shrinkage cracks propagation mechanism due to the influence of overlay materials, interface roughness and bonding strength. Through the laser scanning test and different algorithms, e.g. random cutting and random midpoint interpolation algorithm, geometry models of the 2D actual aggregate and rough interfaces with different fractal dimensions were generated. Besides, zero-thickness cohesive elements were inserted in mesh as the reserved path for cracks by modifying the inp file of ABAQUS. The validity of the model was verified by comparing with LI's experiment. Results of the simulation suggested that the final length of surface cracks and interface debonding depended on the overall shrinkage of the repair system and surface cracks mainly occurred in high bonding strength cases; aggregate nearby the interface caused the initial damage at low bonding strength interface, leading to the "stepped" debonding with time; The rough interface was more difficult to debond because it required more fracture energy and local shear stress was converted into compressive stress to prevent the development of debonding.