Evaluation of effectiveness of silicoorganic treatments using hydric properties

14 páginas, 1 tablaIn this work, the effectiveness of silicoorganic treatments for the consolidation, with or without waterproofing, of silicified stones (one conglomerate and four sandstones) from Zamora is analyzed, provided that these treatments are applied in the same way. Changes in the following properties have been monitored: total and free porosity, real and apparent density, absorption coefficient, imbibition coefficient, and capillary absorption coefficient. These intrinsic stone properties and the treatments employed have a significant effect on changes in these variables and lead to differences in the transport of fluid in the stone. This is the first time that the Canonical Biplot has been applied to this type of data to determine the control of the effectiveness of silicoorganic treatments applied to rocks. It was observed that the double action treatment RC80, which includes both waterproofing and consolidating, is more effective than the consolidating treatment RC70.The authors are grateful for financial support for this work from the Ministry of Education and Science (CGL2007-62168BET and FEDER funds) and Ministry of Science, Innovation (MAT2010-20660) and Ministry of Science, Innovation and Universities (PGC2018-098151-B-100).Peer reviewe

Multivariate analyses of soluble salts responsible for pathologies in granites of the roman aquecuct of Segovia, Spain.

8 páginas, 2 figuras, 3 tablasThe aim of this work is to characterize the main pathologies caused by salt crystallization in granitic monuments (crusts, salt efflorescence, disaggregation and disaggregation with salt efflorescence). Water soluble ions were determined quantitatively. Using the Canonical Biplot multivariate method it was determined that: a) there is a relationship between the content of water soluble salts and the different identified pathologies; b) sulphate and NO3 -, Cl-, Ca2+, Mg2+, K+ and Na+ ions are the major components of salt efflorescence; c) carbonate is a major component of the crust; and d) the disaggregated granites, with or without salt efflorescence, have a low proportion of soluble salts but no predominant ion composition.The authors are grateful for the funding received from the Town Hall of Segovia, and the National Plan project funded by the Ministry of Education and Science (CGL2007-62168BET and FEDER funds) and Ministry of Science and Innovation (MAT2010-20660)], which permitted this work to be carried out.Peer reviewe

Evaluation of colorimetric changes in the Itaquera granite of the Ramos de Azevedo Monument, São Paulo, Brazil

10 páginas, 6 figurasItaquera Granite, as a building stone material, was widely used in the early 20th century for the construction of buildings and monuments in the centre of the city of São Paulo, Brazil. The color variation of the Itaquera Granite of the Ramos de Azevedo Monument was monitored for two years and these data were compared with those obtained for fresh stone originated from a historic quarry. The oxidation of iron-rich minerals present in this granite, coupled with pollution (high levels of O3), biological colonization, leaching of bronze, and the dissolution and reprecipitation of mortar, causes colorimetric changes in the stone. Measurements were also performed on zones of the monument with pathologies. Two statistical Canonical Biplot analyses were made on the data of chromatic coordinates monitored (L*, a*, b*, C* and H*): orientation/year and orientation/pathologies. The results obtained for the chromatic variation in the monument are primarily related to yellowing caused by deposition of atmospheric pollutants and weathering of iron-rich minerals.FAPESP (Foundation for Research Support of the State of São Paulo) for granting the master’s scholarship (proj. no. 2011/03728-0) and research grant (proj. no. 2009/02519-8)Peer reviewe

Geología en la calle: un acercamiento a la geografía física de tu comunidad

Memoria ID-0214. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2014-2015

Geotools, a 3D approach (GIS) for understanding morphometric parameters of drainage networks in civil engineering and geological sciences

Memoria ID-0213. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2014-2015

La personalidad pétrea de las ciudades: el papel de la Geología para el caso de Salamanca

Memoria ID12-0181. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2012-2013

New Perspectives for UAV-Based Modelling the Roman Gold Mining Infrastructure in NW Spain

This contribution discusses the potential of UAV-assisted (unmanned aerial vehicles) photogrammetry for the study and preservation of mining heritage sites using the example of Roman gold mining infrastructure in northwestern Spain. The study area represents the largest gold area in Roman times and comprises 7 mining elements of interest that characterize the most representative examples of such ancient works. UAV technology provides a non-invasive procedure valuable for the acquisition of digital information in remote, difficult to access areas or under the risk of destruction. The proposed approach is a cost-effective, robust and rapid method for image processing in remote areas were no traditional surveying technologies are available. It is based on a combination of data provided by aerial orthoimage and LiDAR (Light Detection and Ranging) to improve the accuracy of UAV derived data. The results provide high-resolution orthomosaic, DEMs and 3D textured models that aim for the documentation of ancient mining scenarios, providing high-resolution digital information that improves the identification, description and interpretation of mining elements such as the hydraulic infrastructure, the presence of open-cast mines which exemplifies the different exploitation methods, and settlements. However, beyond the scientific and technical information provided by the data, the 3D documentation of ancient mining scenarios is a powerful tool for an effective and wider public diffusion ensuring the visualization, preservation and awareness over the importance and conservation of world mining heritage sites

Implantación de una metodología multidisciplinar para la conservación de los materiales pétreos en el patrimonio monumental

Memoria ID12-0180. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2012-2013

Estudio estratigráfico y paleogeográfico de la Unidad Informal de San Miguel de Pedroso (Neógeno del Pasillo de Los Montes de Oca, Burgos)

The stratigraphy and sedimentology of the San Miguel of Pedroso unit from the Oca's Mountain Corridor (Between Duero Basin and Ebro). Its Palaeogeography during Neogene as well as these materials show important lateral variations. Their most important characteristics (composition, facies, distribution, etc.) are studied. They are interpreted as fluviolacustrine sediments and they've been summarized in this pape

Decay and preservation of building stones in non polluted enviroments (Spain)

Preservation of our Historical Cultural Heritage built in stone requires studies on the material itself, on the environment where the monument is located, and even on the microclimate affecting a particular stone in the building. Conservation treatments should be also non-agressive and restoration works should respect the chemical and mineralogical properties and surface characteristics or aesthetic aspect (colour) of the stones already existing in the monument. We have studied the intrinsic factors of several types of stones and their role in the type of degradation found in each case. Together with air pollution, salt crystallization seems to be one of the most important agents of decay, especially on porous stones and in environments where heating/cooling and wetting/drying cycles exist. Most of the results reported have been obtained on sandstones (arkosic) and granite materials used in building and restoration of monuments in Avila and Salamanca (World Cultural Heritage cities in Spain). The positive effect of several conservation and prevention treatments containing organic silicates and polysiloxane compounds, as well as methods for extracting salts by natural clays, have been studied. The results obtained represent an adequate way to evidence the problems and some of the solutions to solve them.Authors thank financial support from MCyT (grant MAT2000-0972-C02-01) and Junta de Castilla y León (CSI08/03). JGT and ACI acknowledge I3P grants from CSIC. This work is dedicated to the beloved memory of Dr. M. Angeles Vicente