Effect of Confinement on Properties and Characteristics of Alkali-Silica Reaction Gel

Abstract

This paper studies how steel microfibers can generate confinement of the resulting alkali-silica reaction (ASR) gel. ASR gel, which develops as a byproduct between certain types of aggregates and the cement paste, can lead to crack formation in concrete. As the amount of local confinement found within the material determines the degree of damage, the research also investigates how confinement affects the formation and characteristics of the ASR gel. Both solid and liquid forms of ASR gel are studied, via microprobe analysis (to determine chemical composition) and inductive coupled plasma spectroscopy. The research also measures the viscosity of the liquid alkali-silicate solution. Results show that the use of steel microfibers in controlling cracks leads to a chemo-mechanical confinement of the ASR gel. The authors note that this type of confinement reduces volumetric expansion, ASR gel formation, and the reactivity of the reactive aggregate.