The Leeb Hardness Test for Rock: An Updated Methodology and UCS Correlation

Corkum, A. G.; Asiri, Y.; Naggar, Hany El; Kinakin, Derek

doi:10.1007/s00603-017-1372-2

Cited by 50 publications

(29 citation statements)

References 12 publications

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“…Our data on the influence of thickness and volume for four sandstones confirms and adds a wider body of evidence to the work of Corkum et al (2018). Indeed, our data indicate that even smaller block sizes can give reliable results.…”

Section: Discussionsupporting

confidence: 84%

“…The appropriate numbers of readings for a robust test measurement on the sandstones studied have been evaluated through using the method of Corkum et al (2018) as 20 for D and C probes. These are much smaller than the 45 readings recommended by Wilhelm et al (2016b) for some limestones.…”

Section: Discussionmentioning

confidence: 99%

“…Previous studies have produced different empirical relationships between UCS and Equotip hardness data (sometimes including density or porosity as well) for a range of rock types (Kawasaki et al, 2000;Aoki and Matsukura, 2007;Yilmaz, 2013;Asiri et al, 2016). Corkum et al (2018) present a good summary and compilation of these and conclude that power functions provide the best fit, with different coefficients for different rock types.…”

Section: Introductionmentioning

confidence: 95%

“…Yilmaz, 2013; Wilhelm et al, 2016b;Asiri et al, 2016;Corkum et al, 2018). Yilmaz, 2013; Wilhelm et al, 2016b;Asiri et al, 2016;Corkum et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

“…Despite the popularity of the Equotip and other similar rebound devices to measure rock and stone surface hardness, there are no standards for generating Equotip data on these materials, although several papers have proposed different methods of data collection, index calculation and statistical analyses (e.g. Yilmaz, 2013;Wilhelm et al, 2016b;Asiri et al, 2016;Corkum et al, 2018). Standards exist for the Schmidt Hammer (e.g.…”

Section: Introductionmentioning

confidence: 99%

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A laboratory study of Equotip surface hardness measurements on a range of sandstones: What influences the values and what do they mean?

Désarnaud

Kiriyama

Biçer-Şimşir

et al. 2019

Earth Surf Processes Landf

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The Equotip rebound tester is a simple, non‐destructive technique to measure the surface hardness of materials. Having a low impact energy gives the Equotip advantages over the commonly used Schmidt Hammer on weathered rock and stone. In this study we have investigated the influence of different parameters (sample size, moisture content and surface roughness) on the surface hardness values obtained from freshly cut blocks of four types of sandstone. In a series of laboratory experiments both Single Impacts (SIM) and Repeat Impacts (RIM) methods have been used with C and D probes (which have different impact energies). Our results show that whilst sample size is of great importance we find that smaller samples can be reliably evaluated than previously reported. Moisture contents are also found to exert a more important influence on both SIM and RIM results than previously thought, with up to 26% lower hardness values recorded on saturated vs dry sandstone. Conversely, we find that surface roughness (over Sz values of 100 to 800 microns) does not have a significant impact on SIM measurements collected using the D probe. Both SIM and RIM data are found to be good proxies for compressive strength and open porosity, with SIM data collected with the C probe showing the best fits. Data collected using 3D microscopy helps visualize and quantify the small impact marks created by the Equotip and confirms that these are much reduced when using the C vs D probe. The results highlight the benefits of the Equotip to studies of the nature and deterioration of sandstone, the need for careful evaluation of any confounding factors which might influence the values obtained, and illustrate the different advantages of C and D probes. © 2019 John Wiley & Sons, Ltd.

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Section: Discussionsupporting

confidence: 84%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 95%

“…Yilmaz, 2013; Wilhelm et al, 2016b;Asiri et al, 2016;Corkum et al, 2018). Yilmaz, 2013; Wilhelm et al, 2016b;Asiri et al, 2016;Corkum et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

A laboratory study of Equotip surface hardness measurements on a range of sandstones: What influences the values and what do they mean?

Désarnaud

Kiriyama

Biçer-Şimşir

et al. 2019

Earth Surf Processes Landf

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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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A Three Hinge Buckling Laboratory Test

Ghasemi

Corkum

2020

Rock Mech Rock Eng

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The Leeb Hardness Test for Rock: An Updated Methodology and UCS Correlation

Cited by 50 publications

References 12 publications

A laboratory study of Equotip surface hardness measurements on a range of sandstones: What influences the values and what do they mean?

A laboratory study of Equotip surface hardness measurements on a range of sandstones: What influences the values and what do they mean?

Lichen impact on sandstone hardness is species‐specific

A Three Hinge Buckling Laboratory Test

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