The effects of different cementitious binders on expansion induced by alkali silica reaction

Author(s): Taehwan Kim, Dinesh Arachchige, Quang Dieu Nguyen, Mohammad Khan, Arnaud Castel
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: 200
Total Pages: 813
Language: English

Abstract: Different types of cementitious materials have been developed and investigated to construct and restore infrastructure in an economical, durable, and sustainable manner while reducing carbon footprint. However, the durability of concrete using these alternative cementitious materials has yet to be fully investigated and the results are still controversial. This paper presents the effect of different binders on alkali silica reaction (ASR). It is expected that each binder involves different chemical reactions, consequently, resulting in different mortar systems for ASR to occur.
Six different mortar mixtures were prepared using a highly reactive aggregate, including: a) one portland cement mixture, b) three geopolymer mixtures (9, 4, and 1 of fly ash to ground granulated blast furnace slag (GGBFS) ratios), and c) two limestone calcined clay cement (LC3) mixtures (20% and 30% of replacement rates). The accelerated mortar bar tests were performed for an extended period. ASR phases of different mixtures were investigated using Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) at different exposure time in NaOH solution. Dissolution behaviors of the reactive aggregate were monitored in four different NaOH solutions.
The expansions of three geopolymer mortars showed initial delay (about 20 days). It implies that the geopolymer system requires an extended test period to assess the ASR expansion. The higher content of GGBFS in geopolymer binder caused the greater expansion, which indicates the calcium content is associated with the expansion induced by ASR. ASR gels observed from SEM-EDS also supported the effect of calcium on the expansion. The LC3 mortars significantly reduced the expansion of mortar bars at all ages. 30% OPC substituted by calcined clay and limestone restricted the expansion of mortar bars below the 10-day limit and 21-day limit, which can prevent the potential ASR in concrete structure using reactive aggregate.

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

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