The combined effect of alkalis and aluminum in pore solution on alkali-silica reaction

Wei, Shihua; Zheng, Keren; Zhou, Jin; Prateek, Ghimire; Yuan, Qiang

doi:10.1016/j.cemconres.2022.106723

Cited by 22 publications

(5 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The decrease in Si available is likely due to the suppression of reactive silica by the additional Al in solution contributed by the fly ash. [18][19][20] Although the results show the mitigation of fly ash substitution in both the expansion and ERI, the ERI for MR-1-1.55%-FA is larger than would be expected based on Eq. ( 4).…”

Section: Mitigation Of Expansion and Reduction In Eri With Cement Rep...mentioning

confidence: 57%

“…An increase in Al in the simulated pore solution corresponds with a mitigation of expansion potential and has shown mitigation in other studies. [18][19][20] The final component of the T-FAST results is the Ca concentration, which has generally exhibited more mixed data regarding its role in ASR expansion, but in the T-FAST model is shown to reduce the expansion potential. 3,15,16,[21][22][23][24] Combined, these concentrations form a chemical reactivity index, shown in Eq.…”

Section: Chemical Testing Of Expansion Susceptibilitymentioning

confidence: 99%

See 1 more Smart Citation

Chemical Detection of Expansion Susceptibility of Concrete

2024

View full text Add to dashboard Cite

This experimental study evaluated the correlation between measured concrete expansion from a modified version of the miniature concrete prism test (MCPT) with the concentration of chemical markers leached from the prisms into an alkaline soak solution. Fifteen concrete mixture designs were tested for expansion and soak solution concentrations over time. The changes in expansion and soak solution concentrations were found to correlate well even with variations in alkali loading and substitution of cement with Class F fly ash. A model was developed to estimate the expansion potential of concrete based on an expansion reactivity index (ERI) that incorporated the concentrations of silicon, sulfate, calcium, and aluminum. The relationship between ERI and expansion was then used to identify potentially expansive concrete mixtures using the ERI of cores taken from a structure exhibiting potential alkalisilica reaction (ASR) expansion and concrete cylinders matching the mixture designs of the MCPT specimens.

show abstract

Section: Mitigation Of Expansion and Reduction In Eri With Cement Rep...mentioning

confidence: 57%

Section: Chemical Testing Of Expansion Susceptibilitymentioning

confidence: 99%

Chemical Detection of Expansion Susceptibility of Concrete

2024

View full text Add to dashboard Cite

show abstract

“…Table 2 shows the oxide composition reported by some authors. From the results, the major compounds are SiO2, Al2O3, and Fe2O3, with a total of over 96%-98% [12][13][14]. These oxides are those required for the pozzolanic reaction.…”

Section: Characterisation Of Metakaolin 31 Oxide Compositionmentioning

confidence: 99%

“…Wei et al [40] investigated the combined effect of alkalis and aluminium in the pour solution on the alkalisilica reaction using Portland cement (PC) and MK as cementitious materials. The study investigated the effects of alkali ions and aluminium in the pour solution of ASR through an accelerated mortar bar test (AMBT), partially replacing 100% PC with 5% MK with various amounts of NaOH to increase the Na2Oeq from 0.65%, 1.25%, 2.25% and 2.75%.…”

Section: Influence Of Metakaolin In the Mitigation Of The Alkali-sili...mentioning

confidence: 99%

Towards understanding the influence of metakaolin in the prevention of alkali-silica reaction

2022

View full text Add to dashboard Cite

The role of supplementary cementitious materials (SCM) in the prevention and mitigation of the Alkali-Silica Reaction (ASR) in concrete materials and structures is becoming increasingly significant and relevant in the civil engineering. The use of SCMs in South Africa is limited to Ground Granulated Blast-Furnace Slag (GGBS) and Fly Ash (FA) as they are readily available. With recent advancements in concrete technologies, it has been found that calcined clays such as Metakaolin (MK) have been useful in concrete to improve the chemical, mechanical, and physical properties of concrete material. Deposits of MK have been found in some regions of South Africa and are now available for consumption with various applications but have not yet been widely accepted as conventional SCM within the concrete ready-mix industry. This article aims to summarise state-of-the-art and existing knowledge gaps in the application of SCMs in concrete material and identify the feasibility and benefits of extending the use of SCMs with MK in a comparative study with FA Class F and SF. The performance of MK with respect to the key variables such as exposure conditions, reaction mechanisms and pore solution composition in the prevention of ASR in concrete material relative to the mentioned SCMs is discussed.

show abstract

“…Most studies of pore solutions focus on cement pastes cured at room temperature (20-23 • C), a good summary of these can be found in the review by Vollpracht et al [32]. A limited number of studies have investigated the pore solution composition at the elevated temperatures used for expansion testing [15,16,[47][48][49][50][51], but to our knowledge none have systematically compared the impact of increasing the temperature from 20 to 60 • C on the pore solution composition and linked it to ASR expansion.…”

Section: Introductionmentioning

confidence: 99%