An integrated macro-microscopic model for concrete deterioration under external sulfate attack. (December 2020)

• Record Type: Journal Article
• Authors: Yin, Guang-Ji; Zuo, Xiao-Bao; Li, Xiang-Nan; Zou, Yu-Xiao
• Is Part Of: Engineering fracture mechanics. Volume 240(2020)
• Publication Date: 2020-12
• Subjects: Concrete deterioration -- External sulfate attack (ESA) -- Integrated macro-microscopic model -- Crystallization pressure -- Volume increase; Fracture mechanics -- Periodicals; Rupture, Mécanique de la -- Périodiques; Fracture mechanics; Periodicals; 620.112605
• DOI: 10.1016/j.engfracmech.2020.107345
• Languages: English
• ISSNs: 0013-7944

Abstract

Highlights: ESA-induced deterioration of concrete is divided into dormant and detrimental periods. An integrated macro-microscopic model for concrete deterioration is developed. Diffusion, reaction of sulfate and its-induced expansion of concrete can be analyzed. Deterioration process of concrete pipe exposed to Na2 SO4 solution is investigated. Abstract: Concrete deterioration caused by external sulfate attack (ESA) is a macro-microscopically interactive expansion process, including two stages, namely a dormant period and detrimental duration. Based on ESA-induced deterioration mechanism, an integrated macro-microscopic model has been developed to describe the deterioration of concrete. In this model, a critical characteristic related to crystallization pressure is proposed to recognize two stages of ESA, and a criterion of ESA-induced boundary movement in concrete specimen is established by its total damage associated with micro and macroscopic damages. A diffusion-reaction model is constructed to characterize macroscopic sulfate diffusion and microscopic ettringite/gypsum formation in concrete, which are respectively used to determine the crystallization pressure and volume increase. The macro and microscopic mechanical models, combining with the plastic-damage model, are built to analyze the expansion-induced deterioration of concrete. The integrated model is validated by the experimental results of expansion deformation and damage distribution.