Alkali-silica reaction products and cracks: X-ray micro-tomography-based analysis of their spatial-temporal evolution at a mesoscale

Journal Article · Wed Dec 15 04:00:00 EST 2021 · Cement and Concrete Research

DOI:https://doi.org/10.1016/J.CEMCONRES.2021.106593· OSTI ID:23206148

Shakoorioskooie, Mahdieh ^[1]; Griffa, Michele; Leemann, Andreas ^[1]; Zboray, Robert ^[2]; Lura, Pietro ^[1]

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1. Concrete and Asphalt Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf (Switzerland)
2. Center for X-ray Analytics, Empa, Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf (Switzerland)

In this study, we propose a laboratory-scale methodology, based on X-ray micro-tomography and caesium (Cs) as a contrast agent, to advance the understanding of cracking due to alkali-silica reaction (ASR) in concrete. The methodology allows achieving a completely non-destructive and time-lapse characterization of the spatial-temporal patterns of both the cracks and the ASR products. While Cs addition slightly accelerated the ASR kinetics, the crack patterns, with and without Cs addition, were statistically equivalent. Cracks with ASR products appeared first in the aggregates, close to the interface with the cement paste. They propagated afterwards towards the aggregates interior. Some products were then extruded for several mm into air voids and cracks in the cement paste. This process suggests that, in the early stage, the ASR products may be a low-viscosity gel that can flow away from the source aggregate and may settle later elsewhere as a rigid phase, upon calcium uptake.

• OSTI ID: 23206148
• Journal Information: Cement and Concrete Research, Journal Name: Cement and Concrete Research Vol. 150; ISSN 0008-8846; ISSN CCNRAI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CEMENTS
CESIUM
CONCRETES
CONTRAST MEDIA
CRACKING
GELS
IMAGE PROCESSING
INTERFACES
KINETICS
SILICA
TOMOGRAPHY
UPTAKE
VISCOSITY
VOIDS
X RADIATION