Synthesis of alkali-silica reaction (ASR) products and the role of Al and Li in mitigating ASR

Using Al-rich supplementary cementitious materials to partially replace Portland cement is a well-established empirical approach to mitigate expansion of concrete caused by alkali-silica reaction (ASR). However, the mechanisms behind it are still not completely understood. Synthesis of ASR products in the laboratory provides a unique opportunity...

Effect of reactive aggregate on the early age reaction of water-glass activated slag/fly ash mortars

Alkali activated materials (AAMs) have received worldwide attention due to its lower embodied energy and environmental impact than that of traditional cementitious materials. However, the activators with high alkalinity may raise the risk of alkali silica reaction (ASR) induced deterioration when reactive aggregates are used, which thereby...

Experimental investigation of ASR-affected concrete – The influence of uniaxial loading on the evolution of mechanical properties, expansion and damage indices

The alkali silica reaction (ASR) in concrete causes internal localized swelling and micro cracking, which result in expansion and correlated deterioration of the concrete material. The stress state of the concrete is known to affect expansion due to ASR, with an anisotropic stress state giving rise to anisotropic expansion. Similarly, the...

The effect of an embedded cathode on lithium migration in mortar specimens

The currently available treatment techniques for concrete structures affected by alkali-silica reaction (ASR) are limited and electrochemical lithium migration has been proposed as an alternative. Lithium compounds have shown to have beneficial effects on ASR expansion when used as admixtures to fresh concrete. During the electrochemical...

Elastic modulus of the alkali-silica reaction rim in a simplified calcium-alkali-silicate system determined by nano-indentation

This work aims at providing a better understanding of the mechanical properties of the reaction rim in the alkali-silica reaction. The elastic modulus of the calcium alkali silicate constituting the reaction rim, which is formed at the interface between alkali silicate and Ca(OH)2 in a chemically-idealized system of the alkali-silica reaction...

Studies on the alkali-silica reaction rim in a simplified calcium-alkali-silicate system

This work is intended to provide a better understanding about the properties and roles of the reaction rim in an alkali-silica reaction. A simplified calcium-alkali-silicate system was created to simulate the multiple interactions among reactive silica, alkaline solution and portlandite near the aggregate surface during the formation and...

Measuring and modelling the deteriorating impact of Alkali-Silica Reaction in concrete on the mechanical characteristics

Unaffected and ASR-affected concrete, experimentally, appear as substantially different materials. Since the material characterization is one of the main points of attention within a structural assessment, the deteriorating impact of ASR on concrete in terms of both expansion and degradation of the mechanical properties is studied. Both...