Evaluation of sulfate resistance of Portland and high alumina cement mortars using hardness test

Aye, Thidar; Oguchi, Chiaki T.; Takaya, Yasuhiko

doi:10.1016/j.conbuildmat.2009.11.016

Cited by 39 publications

(7 citation statements)

References 26 publications

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“…10. Circular ettringite crystals were detected with their needle-like structure, identical to that identified in the previous research [52,53]. AH 3 can be found in the shape of villous spherical particles that are 1-10 μm, which mainly contains Al and O along with a small amount of Ca [49].…”

Section: Fesemsupporting

confidence: 79%

Development of Cold-Bonded Briquettes Using By-Product-Based Ettringite Binder from Ladle Slag

Abdelrahim

Nguyen

Omran

et al. 2022

J. Sustain. Metall.

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The recycling of steel plant side streams through cold-bonded briquettes has become quite common. However, Portland cement is mainly used as a binder in the briquettes, contributing significantly to the energy consumption, costs, and carbon footprint associated with the production of cold-bonded briquettes. This paper reports on a more sustainable method for side stream recycling that involves replacing cement with an ettringite-based binder. Ettringite binders develop early high strength and mainly consist of ladle slag, another side stream of the industry. Here, the ettringite-based binder is assessed in terms of its mechanical and thermal properties against a reference briquette made using the conventional technique. Three different briquette types are produced using several side stream materials and varying ettringite-based binder content. Briquettes produced using 15% and higher ettringite-based binder content exhibited excellent mechanical properties within a shorter curing period compared to conventional used binder. Moreover, the ettringite-based binder briquettes exhibited a better swelling behavior to conventional cement briquettes under conditions simulating a blast furnace. Graphical Abstract

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Section: Fesemsupporting

confidence: 79%

Development of Cold-Bonded Briquettes Using By-Product-Based Ettringite Binder from Ladle Slag

Abdelrahim

Nguyen

Omran

et al. 2022

J. Sustain. Metall.

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“…For each series of readings from the surface layers (a, b, and c measurements), a relative surface hardness (RSH) value ( sensu Aye et al, 2010, Kamh & Koltuk, 2020) was obtained, that is the ratio between the median value and the median value of the series of readings from the core of the same block (d measurement). The value, reported as a percentage (RSH % ), represents the variation of stone hardness due to edge effects (a) and bioweathering (b and c) compared with unweathered stone hardness (d):

{RSH}_{%} goodbreak= ((), {median}_{surface ((), normala, normalb, normalc)} / {median}_{core ((), d)}) goodbreak\times 100 - 100 .

…”

Section: Methodology and Methodsmentioning

confidence: 99%

Lichen impact on sandstone hardness is species‐specific

Tonon

Bernasconi

Martire

et al. 2022

Earth Surf Processes Landf

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The balance between lichen biodeterioration and bioprotection processes on stone surfaces depends on many variables and is crucial to understanding the role of lichens in biogeomorphology and their threat to stone heritage conservation. However, stones colonized by lichens have still been mostly examined in terms of affected volumes and physico-chemical modes of interactions, overlooking the overall effects on properties related to surface durability. In this study, the impact of lichen colonization patterns on Cortemilia sandstone was examined beneath thalli of three lichen species. Rock hardness, a proxy for rock durability, was measured at different depths from the surface using an Equotip hardness tester and compared to that of freshly cut surfaces and exposed surfaces uncolonized by lichens. Mineralogical analyses were performed by X-ray powder diffraction on rock beneath lichen colonization, in comparison with unweathered rock. Equotip analyses quantified a differential, species-specific decrease in stone hardness. This variability was related to differences in hyphal penetration patterns and, possibly, calcite (re-)precipitation. In particular, in the case of the species most impacting rock hardness, X-ray diffraction patterns of calcite showed a remarkable stability of crystallographic plane (01-12), known to be enhanced in the presence of organic chelants. These results confirm that decisions on lichen removal from stone surfaces should consider species-specific behaviour. Moreover, the innovative approach of measuring stone hardness variation in association with the analysis of biomineralization processes contributes to unveil the extension of the sphere of lichen interaction within the stone substrate beyond the limit of the hyphal penetration.

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“…The instrument has also been used to study mechanical properties, such as compressive strength and elastic modulus, of rock materials (Hack et al 1993;Muramiya et al 2011). This tester has further been used to measure the surface hardness of concrete exposed to sulfuric acid and salty environments (Aye et al 2010;Coombes et al 2013).…”

Section: Proposed Measurement Methods Using An Equotip Hardness Testermentioning

confidence: 99%

A Simple Method to Evaluate the Depth of Concrete Degradation by Fire

Kubo

Hirata

Yashiro

et al. 2019

ACT

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A method was developed to estimate the depth of concrete degradation caused by a fire using the rebound number measured with a compact Equotip hardness tester. The method was experimentally verified by measuring a core taken from a concrete specimen heated according to the RABT curve to confirm the distribution of the rebound number from the heating surface. The results were then compared with the distribution of the residual compressive strength estimated from the heated temperature of the concrete specimen and further measured with a core taken from the specimen. This confirmed that the distribution of the damage depth of concrete can be simply estimated by measuring the rebound number of test pieces obtained by cutting a core sample in half. The distribution of the damage depth coincides with the distribution of the measured compressive strength and the residual compressive strength estimated from the temperature data obtained in the fire resistance test.

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Evaluation of sulfate resistance of Portland and high alumina cement mortars using hardness test

Cited by 39 publications

References 26 publications

Development of Cold-Bonded Briquettes Using By-Product-Based Ettringite Binder from Ladle Slag

Development of Cold-Bonded Briquettes Using By-Product-Based Ettringite Binder from Ladle Slag

Lichen impact on sandstone hardness is species‐specific

A Simple Method to Evaluate the Depth of Concrete Degradation by Fire

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