Optimization of concrete prism test for ASR expansion by alkali-wrapping and a new approach assessing the alkali reactivity of concrete for nuclear facilities

Author(s): Kazuo Yamada, Yuichiro Kawabata, S. Ogawa, K. Shibuya, J. Etoh, A. Teramoto, G. Igarashi
Paper category: Proceedings
Book title: Proceedings of the International Conference on Sustainable Materials Systems and Structures (SMSS2019) Durability, Monitoring and Repair of Structures
Editor(s): Ana Baričević, Marija Jelčić Rukavina, Domagoj Damjanović, Maurizio Guadagnini
ISBN: 978-2-35158-217-6
e-ISBN: 978-2-35158-218-3
Publisher: RILEM Publications SARL
Publication year: 2019
Pages: 152-159
Total Pages: 813
Language: English

Abstract: There are many testing methods to evaluate the alkali reactivities of aggregates. However, the expansion of concrete by the alkali-silica reaction (ASR) is determined by many factors other than the characteristics of the aggregate, and the acceptable level of expansion and design life depends on the type of structure in which the concrete is used. Therefore, a performance evaluation or a quantitative expansion estimate of the concrete mixture that takes into account environmental conditions is required. The concrete prism test is a promising method for a reliable test procedure; however, the traditional test suffers from alkali loss from the test prism, known as alkali leaching, and insufficient moisture supply during the test. These problems may be avoided by wrapping concrete prisms with a wet cloth containing an alkaline solution, whose pH is close to that of pore solution in the concrete. This process is called AW-CPT. In order to assess the alkali reactivity of concrete, especially for nuclear facilities, not only AW-CPT but also the holistic procedure is required. A new approach was proposed combining petrographic observations, an accelerated mortar bar test at 80 oC, and an AW-CPT at 60 and 40 oC depending on the reactivity of aggregate.

Online publication :2019
Publication type : full_text
Public price (Euros) : 00

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