• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2004.04a
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• pp.147-155
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• 2004

• Journal of Conservation Science
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• v.26 no.3
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• pp.325-334
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• 2010

In order to clarify the effect of consolidant, the artificial porous material with low intensity was manufactured using granite powder and Portland cement. We have prepared four kinds of alkoxysilane system consolidants, a acrylic resin and a epoxy resin and investigated about characteristics before and after consolidation. As a result of the research, Silres BS OH 100 was effective for density and surface hardness. SS-101 with hydrophobicity and Site SX-RO with hydrophilicity had the good durability over salts weathering. On the other hand, Syton HT-50 and Paraloid B72 were easily destructed by salt weathering because they were concentrated on surface area by the low penetration depth. Araldite 2020 was the most effective consolidant for improvement of physical properties.

• Journal of Conservation Science
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• v.28 no.3
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• pp.285-296
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• 2012

This study was to assess the effect of consolidation for intension measures of stone cultural heritage using artificially weathered stones. We have prepared four kinds of stones (Gyeongju Namsan Granite, Iksan Granite, Yeongyang Sandstone, Jeongseon Marble), and manufactured fresh, weathered and highly weathered stone samples by thermal shock for each rock type. The samples were treated with three consolidants (Wacker OH 100, Remmers KSE 300, 1T1G) by three methods {immersion, capillary rise (partial immersion), spray}, and tested for weight, porosity, ultrasonic velocity, Equotip hardness and color before and after treatment. As a result, the effect of consolidation was widely influenced by porosity and treatment methods. Wacker OH 100 was shown the highest consolidation effect in almost every stone sample.

• Economic and Environmental Geology
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• v.28 no.3
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• pp.251-257
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• 1995

Three PEA (Pulverised Fuel Ash) samples, which were fresh, 17 and some 40 years weathered, were collected from two major British power plants. Batch leaching tests with these samples using distilled water and simulated industrial leachate showed higher amounts of element liberation from fresh ash, including Ca, Na, K, S (as $SO^{2-}_4$, $Cr_{total}$, Cu, Li Ni, Mo and CI and this seems to indicate their surface association and easier dissolution when contact with water. On the contrary Mg, Al, Ba, Si, V, As and Se do not show such readily leachable concentrations and these elements might be more associated with glass fraction in PFA particle rather than surface. Although element concentrations in the weathered ash are much lower than those in the initial leachate from the fresh ash, elements are still detected as resonable concentrations, with rather constant levels and this seems to demonstrate the element release from unstable glass phase of PFA particle. Fe, Ca, $Cr_{total}$, Cu, Ni, Zn and Hg were removed from the synthetic leachate by PFA and this is also confirmed by gain in solid PFA. The order of element retention is Meaford weathered ash > Drax weathered ash > Drax fresh ash in decreasing order and this conforms with the degree of weathering. Namely, the more wethered, the more wethered, the more effective in metal retention from the synthetic leachate.

• Journal of the Korean Geotechnical Society
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• v.22 no.7
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• pp.55-64
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• 2006

Shallow failures of slopes in weathered soils are caused by infiltration caused by prolonged rainfall. These failures are mainly triggered by the deepening of the wetting band accompanied by a decrease in suction induced by the water infiltration. In this paper, hysteresis on soil-water characteristic curve (SWCC) of granite and gneiss weathered soils is investigated using transient flow analysis respectively. Each case was subjected to artificial rainfall intensities and time duration depending on the laboratory-based drying and wetting processes. The results show that the unsaturated seepage on weathered slopes are very much affected by the initial suction of soils and unsaturated permeability of the soils. In addition, a granite weathered soil has a lower air-entry value, residual matric suction, and wetting front suction and less hysteresis loop than a gneiss weathered soil.

• Tunnel and Underground Space
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• v.19 no.4
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• pp.287-303
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• 2009

Rock mass in Baekrokdam at the summit of Hallasan in Jeju island is composed of two volcanic rock types: Baekrokdam trachybasalt at the eastern region and Hallasan trachyte at the western region. On-going rockfall and subsequent collapse of Baekrokdam wall rock are closely linked to the weathering of trachyte distributed in the western region of Baekrokdam. Samples of Hallasan trachyte showing different weathering grades had been collected and the polarizing microscopic observation, X-ray diffraction analysis and analysis for chemical weathering had been conducted. Formation of secondary minerals, especially clay minerals, by chemical weathering has not been identified, but the change of chemical weathering indices indicated that chemical weathering process had been proceeded to the degree for increasing and decreasing the contents of some chemical components. Changes in physical and mechanical rock properties due to weathering has also been examined. Artificial weathering test of freezing-thawing reveals that the process of crack initiation and propagation deteriorated the mechanical characteristics of Hallasan trachyte and $D_B$ = 1.5 or porosity = $20{\sim}21%$ would be the ultimate limiting value induced by the mechanical weathering processes.

• Journal of the Mineralogical Society of Korea
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• v.28 no.2
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• pp.135-145
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• 2015

In order to predict the deterioration of stone monument due to acid fog, an artificial fog test using pH4.0 and pH5.6 was applied to the Gyeongju Namsan granite, decite and marble. After the test had weathered Gyeongju Namsan granite a larger weight reduction due to acid fog than fresh one. Decite has shown the most significant changes among the tested rocks with about 0.005 % of weight reduction. Decite and weathered granite will have considerable weight reduction due to acid rain than the acid fog, whereas the marble was expected to show a weight reduction regardless of the phase of water. The porosity and water absorption rate of weathered granite had significantly increased. This result means that the weathered rock is predicted to be more susceptible to acid fog than the fresh rock. The absorption rate of the marble after the test had shown approximately 50 % increase. The color of the samples had slightly changed towards yellow, such tendency was greater shown in weathered rocks. The marble reacted with acid fog had an increased whiteness. A large amount of cation in the samples is caused mainly by the dissociation of minerals through the reaction with acid fog.

• Journal of Conservation Science
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• v.29 no.3
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• pp.249-259
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• 2013

This study was experimented on accelerated weathering test using salt and freeze-thaw to prove effects of consolidants and consolidation for stone cultural heritage. The samples used four kinds of stones (Gyeongju Namsan Granite, Iksan Granite, Yeongyang Sandstone and Jeongseon Marble) which to distributed by three type of weathering grade (Fresh, Weathered Stone and Highly Weathered Stone) added for thermal treatment. The samples were treated with three consolidants (Wacker OH 100, Remmers KSE 300 and 1T1G), and tested by 500 cycles with freezing-thawing and 50 cycles of salt weathering test. As a results of freezing-thawing test, the crack and destruction occurred from some samples. And total immersed samples maintained effect of consolidation to 200 cycles. Also, The rock particle was fall off and gradually destructed by salts weathering test. The consolidated sample relatively had fewer changes by the weathering than not treated sample. The sprayed sample had not continuous effect on weathering.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.65-70
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• 2005

A low resistivity zone is found in many places such as a fractured fault zone, weathered zone and aquifer. The electrical resistivity is influenced mainly by pore fluid as well as the clay mineral types and contents, Hence, it is very important to understand the relationship between the electrical resistivity and clay contents associated with the low resistivity zone for geotechnical applications such as civil engineering. This study examines the characteristics of clay mineral types and contents to electrical resistivity through sample measurements, and proposes an expression relating the resistivity and clay content. The electrical resistivity is measured for an artificial agar specimen with clay minerals instead of a natural rock. The clay minerals used are Kaolinite and Montmorillonite. Montmorillonite shows remarkably lower resistivity than Kaolinite, although its clay content is fewer than that of Kaolinite. Also, the proposed expression shows a good correlation coefficient as high as 0.89 or more in all clay minerals.

• Journal of the Mineralogical Society of Korea
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• v.26 no.4
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• pp.273-283
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• 2013

The artificial rain (pH 4.0, pH 5.6 and pH 6.85) and weathering simulation test are applied in dolomitic marble for the prediction of deterioration of the stone monuments constructed with carbonate rock by acid rain. pH of the applied rain all increase to about neutral pH after reaction of marble. The contents of $Ca^{2+}$ and $Mg^{2+}$ have increased more than twofold in two acid rain and deionized neutral rain after reaction of marble. The weight of marble is expected to decrease $0.00037kg/m^2$ each test cycle by pH 4.0 rain. This weight reduction rate of marble is 1.4 and 3.1 times more in pH 5.6 and pH 6.85 rain respectively, and 3.7 times more in only artificial weathering test. The compressive strength of marble is expected to decrease 0.2468, 0.1791 and $0.1280kg/m^2$ per test cycle with pH 4.0, pH 5.6 and pH 6.85 rain, respectively. These results mean that more acidic rain more enfeeble the strength of marble. Dolomite and small amount of calcite are precipitated in the rains after reaction of marble.