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A. B. Yavuz 《Environmental Geology》2006,51(2):211-227
?zmir is the third largest city in Turkey and has being the centre of art, culture, tourism and trade activities throughout the 5,000 years of its history. Natural stones brought from different parts of the world have been widely used for construction of the prestigious buildings, monuments and roads etc., in the past in the city. Renovation of the street pavements and public gathering areas in the city centre has been undertaken by the Metropolitan Municipality in 2000 and continued through the year of 2001. These renovation activities have mainly been carried out in the streets running parallel to the sea shore. Volcanic rocks brought from the Central Anatolia Ankara-Gölba?? (andesites) and Kayseri-?ncesu (tuffs) have been used in the renovation works. These rocks have shown extensive deteriorations within 4 years of their usage between 2001 and 2005 under the influence of different environmental factors. In this study, the deteriorations developed in the recently placed volcanic rocks used as kerb and pavement stones in the city centre of ?zmir in the light of their mineralogical, chemical, physical and mechanical properties, used locations and the environmental factors are presented. 相似文献
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Moisture in stone material is the key factor for all stone deterioration processes and also in weathering of cultural heritage. With additional presence of salts in the material the situation gets even more critical. While the properties of pure salts with moisture are well known, knowledge about the interaction of salt mixtures with moisture is still poor. In different approaches the reactions of salt-contaminated stone material on changing moisture were tested in the laboratory. Experiments with different solutions in the Na-Mg-SO4-NO3-H2O system revealed interesting new results on the moisture behaviour of salt-contaminated samples. Theoretical considerations and computer simulations are helpful to interpret the data obtained, but are not yet sufficient to explain the real processes acting on site at the monuments. More encouraging to this fact are complementary studies on visible efflorescences in the same salt system. It is shown how by experimental approaches the understanding on salt-induced stone deterioration is strongly complemented. 相似文献
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甘肃舟曲、武都地区是我国滑坡、泥石流等地质灾害发育最为密集、活动最为频繁的区域之一,该区广为出露的志留纪板岩的水岩劣化进程是滑坡、泥石流高度发育的主要原因之一。研究通过对经历不同次数饱水循环、干湿循环养护后板岩的宏观形态的观测,质量变化、弹性波速和单轴抗压强度的测试,对板岩在两种不同水岩作用方式下裂纹扩展过程、质量、波速和强度等相关指标的变化进行了对比研究,揭示了水岩作用方式下板岩的劣化规律,并初步探讨了板岩在不同水岩作用方式下的劣化机理,为滑坡、泥石流灾害的区划评价和防治提供有益的参考。 相似文献
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This study presents a laboratory study of the following two aspects: (1) the influence of sea laver treatment acid on the
geoenvironmental properties of Ariake Sea tidal mud, and (2) the natural remediation effect on the sea laver treatment acid
contaminated Ariake Sea tidal mud caused by the upward seepage of pore water liquid in the mud. Firstly, the mechanisms of
the transport of sea laver treatment acid in the Ariake Sea tidal mud and the generation mechanisms of the upward seepage
flow in the Ariake Sea tidal mud are discussed. Secondly, a series of one-dimensional laboratory infiltration tests were carried
out to investigate the deterioration of the Ariake Sea tidal mud caused by the sea laver acid treatment practice. Test results
reveal that the acid treatment practice caused considerable change in the geochemical properties of the mud in terms of increase
in sulfide content and decrease in pH value. After the treatment by the sea laver treatment acid, the sulfide content of the
mud even exceeded the safe limit value for the benthos, which represents undesirable living condition for benthos. Thirdly,
series of laboratory fresh seawater infiltration tests for the deteriorated Iida site mud were conducted to illustrate this
natural remediation efficiency. It is found that with the infiltration of the fresh seawater, the sulfide content of the Iida
site mud was considerably reduced and pH value increased to an acceptable range for benthos living in the tidal flat mud.
With the increase in the infiltration time and the hydraulic gradient, the remediation efficiency could be increased. 相似文献
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Analyses of deterioration of the Cappadocian tuff, Turkey 总被引:8,自引:3,他引:5
The Cappadocian tuff contains unique erosional features, the so-called fairy chimneys, some of which in the past were dwelled
in and contain valuable wall paintings. These historical heritages, however, are undergoing chemical and physical deterioration
due to atmospheric effects. For the conservation studies, understanding of the deterioration phenomenon of the tuff is essential.
In this study, engineering geological and physicochemical characteristics of the tuff were determined. The durability of the
tuff was assessed through wetting-drying, freezing-thawing, and salt crystallization. The test results suggest that chemical
weathering may be traced to a depth of 2 cm below lichen-covered surfaces and 20 cm adjacent to discolored joint walls. Based
on durability assessment methods, the tuff may be classified as having poor to very poor durability.
Received: 16 December 1996 · Accepted: 3 April 1997 相似文献
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岩石地球化学特征显示,西天山木札尔特岩群成岩于塔里木原始古陆台内部毗邻陆缘活动带部位.后期木札尔特岩群总体经历3期变质作用和4期变形作用改造:早期低角闪岩相区域动力热流变质作用(M1)与前震旦纪塔里木运动(D1)相对应,构成近EW向断续展布的普通角闪石变质相带;主期角闪岩相区域动力热流变质作用(M2)与奥陶纪末至泥盆纪初的俯冲造山(D2)相对应,宏观上构成近NEE向展布的铁铝榴石-矽线石变质相带;晚期中高绿片岩相区域动力退变质作用(M3)与泥盆纪末至石炭纪末期的同碰撞造山(D3)相对应,宏观上构成叠加于先期变质相带之上的具网结状组构的动力变质带. 相似文献
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The deterioration of buildings and monuments by gypsum is the result of crystallization cycles of this salt. Although gypsum
can dehydrate to a hemihydrate, the mineral bassanite, and to an anhydrate, the mineral anhydrite, this reaction occurs in
nature on a geological time scale and therefore it is unlikely to occur when gypsum is found on and in building materials.
The CaSO4–H2O system appears deceptively simple, however there are still discrepancies between the experimental and thermodynamically
calculated data. The reason for the latter can be attributed to the slow crystallization kinetics of anhydrite. Apart from
this, the large numbers of studies carried out on this system have focused on industrially important metastable phases, such
as the hemihydrate and soluble anhydrite. The paper presents a review of the studies dealing with the phase equilibria of
the CaSO4–H2O system as well as the influence of other salts on the solubility of gypsum. It tries to glean out the relevant information
that will serve to explain the deterioration observed on building materials by the crystallization of gypsum and thus allows
developing improved conservation methods. 相似文献
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