Multi-scale investigation of silane coupling agent for enhanced corrosion resistance in reinforced concrete

• Published in: Construction & building materials Vol. 442; p. 137653
• Main Authors: Ren, Dongya, Su, Shaonan, Wang, Zilin, Luo, Wenrui, Niu, Maoqing, Xu, Qiang, Kong, Lin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 06-09-2024
• Subjects: Digital image correlation technology; Microscopic mechanism; Reinforced concrete; Reinforcement corrosion; Silane coupling agent; Microscopic mechanism; Silane coupling agent; Digital image correlation technology; Reinforcement corrosion; Reinforced concrete
• ISSN: 0950-0618
• DOI: 10.1016/j.conbuildmat.2024.137653

Reinforcement corrosion is a significant factor leading to the deterioration of building performance. In order to enhance the serviceability of reinforced concrete under corrosive environments, this study employs a silane coupling agent (γ-aminopropyltriethoxysilane) for steel reinforcement treatment. The anti-corrosion mechanism, crack propagation patterns, and modified corrosion resistance of the steel are investigated at multiple scales. Experimental techniques such as scanning electron microscopy (SEM), X-ray energy-dispersive spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FT-IR) are utilized to explore the influence of the self-assembled coating of the silane coupling agent on the microscopic morphology, elements, and functional groups of the steel. Concrete specimens with treated reinforcement are fabricated, and electrochemical accelerated corrosion tests are conducted to compare corrosion differences among different specimens. Using untreated specimens as a control group, digital image correlation (DIC) technology is employed to capture the full-field strain and displacement distribution during the loading process. The crack propagation and slip behavior at the steel-concrete interface in the composite specimens are analyzed. The research findings indicate that, at the optimal concentration of 1.2 %, the self-assembled coating of the silane coupling agent successfully adheres to the steel surface, significantly enhancing the interfacial abrasion resistance and mechanical strength of the steel-concrete interface, thereby validating the improved corrosion resistance of the steel. This study proposes the self-assembly mechanism and interfacial enhancement mechanism of the silane coupling agent on steel at multiple scales, contributing to a comprehensive understanding of its effectiveness.
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•Microscopic techniques verified silane coupling agents' mechanism and optimal concentration.•Corrosion resistance of silane-treated steel was confirmed by electrochemical tests.•Digital image correlation techniques showed improved reinforced concrete performance and failure traits.