Influence of stress restraint on the expansive behaviour of concrete affected by alkali-silica reaction

Journal Article · Wed Sep 15 04:00:00 EDT 2010 · Cement and Concrete Research

DOI:https://doi.org/10.1016/j.cemconres.2010.05.002· OSTI ID:21483651

Berra, M ^[1]; Faggiani, G ^[1]; Mangialardi, T; Paolini, A E ^[2]

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1. ERSE S.p.A., Via Rubattino, 54-20134 Milano (Italy)
2. Facolta di Ingegneria, Universita 'La Sapienza', Via Eudossiana, 18-00184 Roma (Italy)

The primary objective of this study was to ascertain whether the Threshold Alkali Level (TAL) of the concrete aggregates may be taken as a suitable reactivity parameter for the selection of aggregates susceptible of alkali-silica reaction (ASR), even when ASR expansion in concrete develops under restrained conditions. Concrete mixes made with different alkali contents and two natural siliceous aggregates with very different TALs were tested for their expansivity at 38 {sup o}C and 100% RH under unrestrained and restrained conditions. Four compressive stress levels over the range from 0.17 to 3.50 N/mm{sup 2} were applied by using a new appositely designed experimental equipment. The lowest stress (0.17 N/mm{sup 2}) was selected in order to estimate the expansive pressure developed by the ASR gel under 'free' expansion conditions. It was found that, even under restrained conditions, the threshold alkali level proves to be a suitable reactivity parameter for designing concrete mixes that are not susceptible of deleterious ASR expansion. An empirical relationship between expansive pressure, concrete alkali content and aggregate TAL was developed in view of its possible use for ASR diagnosis and/or safety evaluation of concrete structures.

• OSTI ID: 21483651
• Journal Information: Cement and Concrete Research, Journal Name: Cement and Concrete Research Journal Issue: 9 Vol. 40; ISSN 0008-8846; ISSN CCNRAI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALKALINE EARTH METALS
BUILDING MATERIALS
COLLOIDS
CONCRETES
DIAGNOSIS
DISPERSIONS
ELEMENTS
EXPANSION
GELS
MATERIALS
METALS
MINERALS
OXIDE MINERALS
REACTIVITY
SAFETY ANALYSIS
SILICA
STRESSES