A new approach to evaluate alkali-silica reactivity using loss in concrete stiffness. (10th April 2018)

• Record Type: Journal Article
• Authors: Islam, Mohammad S.; Ghafoori, Nader
• Is Part Of: Construction & building materials. Volume 167(2018)
• Page Start: 578
• Page End: 586
• Publication Date: 2018-04-10
• Subjects: Alkali-silica reactivity -- Stiffness loss -- ASR-induced expansion -- Concrete cylinder -- Mortar bar -- Failure criteria; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2018.02.047
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Loss of concrete stiffness occurs at 4 weeks, and significantly increases at 26 weeks. Loss of concrete stiffness at 26 weeks of more than 18% is considered as reactive. Loss of concrete stiffness between 4 and 26 weeks of more than 9% is treated as reactive. The proposed limits of loss in concrete stiffness shows a good ASR prediction. Abstract: This paper reports the loss of concrete stiffness due to the adverse effect of alkali-silica reactivity (ASR). The concrete cylinders prepared with fourteen aggregate groups were immersed in water at 20 °C (68°F), and in the 1.0 N NaOH at 80 °C (176°F). The percent loss in stiffness (PLIS) between water- and alkali-cured cylinders was determined at 4 and 26 weeks, and was correlated with the expansion of the mortar bars (immersed in the 1.0 N NaOH at 80 °C (176°F)) containing the companion aggregate source at the test durations of 2, 4 and 8 weeks. The results concluded that the loss in stiffness of the concrete cylinders occurred at 4 weeks, and it significantly increased at 26 weeks. The study also suggested that the ASR classification of the aggregates based on the expansion limits of mortar bars showed a good correlation with that produced from the proposed limit of stiffness loss of concrete.