Comprehensive Evaluation and Analysis of Aging Performance of Polymer-Rich Anchoring Adhesives

TL;DR

This study evaluates how polymer-rich anchoring adhesives degrade under different aging conditions, showing significant strength loss and chemical changes.

Contribution

The study provides a comprehensive comparison of aging effects on polymer adhesives using multiple analytical methods.

Findings

Alkali treatment caused up to 70% reduction in bending strength within 500 hours.

Hygrothermal and water-curing treatments reduced strength by 16–77%, depending on adhesive composition.

Infrared spectroscopy confirmed chemical degradation, including ester group breakage and molecular chain scission.

Abstract

In civil engineering, with the increasing demand for structural reinforcement and renovation projects, polymer-rich anchoring adhesives have attracted much attention due to their performance advantage of having high strength and have become a key factor in ensuring the safety and durability of buildings. In this study, polymer-rich anchoring adhesives underwent three artificial aging treatments (alkali medium, hygrothermal, and water bath) to evaluate their aging performance. Alkali treatment reduced bending strength by up to 70% (sample 5#) within 500 h before stabilizing, while hygrothermal and water-curing treatments caused reductions of 16–51% and 15–77%, respectively, depending on adhesive composition. Dynamic thermomechanical analysis revealed significant loss factor decreases (e.g., epoxy adhesives dropped from >1.0 to stable lower values after 500 h aging), indicating increased rigidity. Infrared spectroscopy confirmed chemical degradation, including ester group breakage in vinyl ester resins (peak shifts at 1700 cm−1 and 1100 cm−1) and molecular chain scission in unsaturated polyesters. The three test methods consistently demonstrated that 500 h of aging sufficiently captured performance trends, with alkali exposure causing the most severe degradation in sensitive formulations (e.g., samples 5# and 6#). These results can be used to establish quantitative benchmarks for adhesive durability assessment in structural applications.

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