Alkali silica reaction in concrete - Revealing the expansion mechanism by surface force measurements
OPEN ACCESS
Loading...
Author / Producer
Date
2024-02
Publication Type
Journal Article
ETH Bibliography
yes
Citations
Altmetric
OPEN ACCESS
Data
Rights / License
Abstract
Alkali-silica reaction (ASR) is a major cause for concrete deterioration worldwide. However, the mechanism leading to cracking has not been identified yet. In this study, the extended Surface Force Apparatus (eSFA) has been used to determine the surface forces of alkali-silica solutions between two atomically smooth mica surfaces. The setup imitates the situation present in reactive concrete aggregates with negatively charged silicate surfaces and negatively charged polynuclear silica in solution. The distance of strong electrostatic repulsion increases with increasing concentration of dissolved silica, leading to the buildup of pressure up to 6 MPa. When the precipitation of ASR products in confined conditions is triggered by the addition of CaCl₂ to the alkali-silica solution, the resulting solidification pressure forces the mica platelets apart and reaches 6–13 MPa. The eSFA experiments shows that solidification pressure is the mechanism leading to aggregate cracking and expansion of ASR-affected concrete.
Permanent link
Publication status
published
Editor
Book title
Journal / series
Volume
176
Pages / Article No.
107392
Publisher
Elsevier
Event
Edition / version
Methods
Software
Geographic location
Date collected
Date created
Subject
Concrete; Alkali-silica reaction; Polynuclear silica; Surface forces; Solidification pressure