Uso de RPAS (Remotely Piloted Aircraft System) para la docencia y divulgación de las Ciencias de la Tierra

Proyecto de Innovación docente enfocado a la elaboración de material audiovisual digital modular basado en las imágenes obtenidas con dron y enfocado a la enseñanza a nivel de grado y master, así como a la divulgación científica.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasFALSEsubmitte

RPAS (Remotely Piloted Aircraft Systems) para la elaboración de salidas de campo virtuales como recursos docentes “flipped classroom” para Grados relacionados con Ciencias de la Tierra

El principal objetivo del Proyecto es continuar con el desarrollo de material docente geológico y de recorridos de interés geológico virtuales además del uso de RPAS (Remotely Piloted Aircraft System) aeronaves no tripuladas que permiten acercarse a zonas de difícil accesibilidad. Este proyecto pretende desarrollar prácticas de campo virtuales mediante el manejo de nuevas tecnologías, tanto usando métodos de adquisición y elaboración de datos geológicos (RPAS: Remotely Piloted Aircraft System) como para su presentación y uso de la información y comunicación (TICs)

Long-Term Behavior of the Micro-Texture of Aggregates Used on Roads Subjected to Extreme Climate Conditions and Winter Maintenance Operations

The micro-texture of fine and coarse aggregates used on roads is one of the main factors responsible for the skid resistance of asphalt pavements. However, the long-term behavior of this property regarding the effects of traffic and climate conditions has been poorly studied. Therefore, in this paper, two types of aggregates, schist and amphibolite, commonly used on roads that are subjected to winter maintenance actions and high temperatures in summer have been studied. The micro-texture of the aggregates has been characterized with an optical roughness tester, fluorescence microscopy and the Polished Stone Value test. The extreme climate conditions have been simulated in a laboratory with durability tests (freeze-thawing and thermal stress cycles) including the NaCl used as deicer during winter maintenance operations. Results have shown that the wearing mechanisms of the aggregates? surfaces are different regarding their composition and internal texture. On schist aggregates, weather conditions applied do not significantly deteriorate their micro-texture. However, the combined effect of traffic and extreme climate conditions with NaCl, double the decrease of the surface roughness measured when these aggregates are subjected to extreme climate conditions in the laboratory, improving, in some cases, their skid resistance. Conversely, the external factors considered have the same effect on the micro-texture of the analyzed amphibolite aggregate

The origin and development of natural cements: The Spanish experience

Natural cement first appeared in England in 1796. Industrial production did not begin in Spain until the second half of the 19th century. Small scale production of natural cement started in different parts of the north and northeast of the country (the Basque Country and Catalonia) toward the end of the first half of the 19th century. This non-industrial manufacture took advantage of the infrastructure that existed at the time for the production of lime. Later industrial manufacture required important technological and logistical improvements. With the advent of large-scale production, the manufacture of natural cement became specialised, producing different cements with specific properties to satisfy different needs.Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

Thermal stress-induced microcracking in building granite

Microcracking induced by wide fluctuations in temperature affects granite quality and durability, making the stone more vulnerable to decay. Determining the extent of that effect is not always straightforward, however, given the excellent durability of these materials.Four types of construction granite quarried in the region of Madrid, Spain, and frequently used in both the built heritage and in de novo construction (Alpedrete, Cadalso de los Vidrios, Colmenar Viejo and Zarzalejo) were exposed to 42 thermal cycles (105-20 °C; UNE-EN, 14066, 2003). Petrographic and petrophysical properties were analysed using both destructive and non-destructive techniques. Microcracking generated in the granite stones by 42 thermal cycles had barely any impact on their petrophysical properties, which are the parameters normally assessed to establish material quality and durability. Their petrographic properties, which are not generally assessed in this type of studies, were affected, however. This study contends that petrographic analysis is needed to objectively quantify the actual quality and durability of the most highly resistant materials when petrophysical studies are inconclusive. Petrographic and fluorescence microscopy, along with fractography, are among the most prominent techniques for petrographic exploration. Thanks to the deployment of these techniques, mineral microcracking could be monitored throughout the present tests conducted.The microscopic findings revealed substantial micro-textural and microstructural change in and around the granite minerals, which play a prominent role in decay. The findings showed that pre-existing microcracks coalesced and generated further microcracking as decay progressed. Microcracking was most intense in Zarzalejo granite due to its textural characteristics determined by its high feldspar content. Microscopic observation revealed that the microstructure of feldspar minerals, with their crystallographic anisotropies and secondary mineral phases, favoured microcrack development. Zarzalejo granite exhibited lower quality and durability than Colmenar Viejo and Cadalso de los Vidrios granites, which were more resistant to heat treatment

Determination of anisotropy to enhance the durability of natural stone

Received 30 November 2010 / Accepted for publication 8 July 2011 / Published 23 August 2011 /Online at stacks.iop.org/JGE/8/S132 Copyright © 2011, Oxford University Press © 2011 NanjingGeophysical Research InstituteAnisotropy is a petrophysical property of natural stone and other construction materials thatdetermines their quality and resistance to decay due to a variety of agents, such as water. A studywas conducted on nine types of stone widely used in Spain’s built heritage, using six previouslydefined anisotropy indices. These indices can be used to determine the degree of anisotropy,which helps explain the differential decay observed in stone materials quarried in the same bedand used to build the same structure. The conclusion reached is that anisotropy should bedetermined in the natural stone used both to restore the architectural heritage and in newconstruction, since the appropriate choice of material quality ensures greater resistance to decayand, therefore, increased durability. Materials with the lowest possible anisotropy should beselected, as this property governs their hydraulic behaviour: the lower the anisotropy in amaterial, the better its behaviour in relation to water and the longer its durability.Comunidad de Madrid (España)Ministerio de Educación y Ciencia (España)Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

Analytical characterisation of 1st- and 2nd-century Roman mortars at the Utica archaeological site (Tunisia): Construction phases and provenance of the raw materials

The aim of this paper is to characterise the mortars from at the Roman site in Utica, Tunisia. In-depth knowledge of the composition of these Roman mortars is necessary to ensure the proper restoration and preservation of these ancient monuments. Despite the significance of this archaeological site, declared a UNESCO World Heritage Site in 1993, the Roman construction materials used there, particularly the mortars have never been analysed. The findings of this study allowed us to determine the particularities of the Roman mortars in Utica, highlighting the impact that local know-how, geological specificity and the history of the archaeological site had on the end product. The different mortars were analysed using petrographic (optical polarised and electron microscopes), mineralogical (X-ray diffraction), chemical and physical techniques. Three types of joint and coating mortars, associated with two different construction phases and a variety of uses, were identified. The mortars used in the city's first construction phase were low-hydraulicity calcium lime mortars containing inert quartz aggregates. Those related to the city's second phase of construction, are two types of mortar with a greater degree of hydraulicity by virtue of their artificial and natural pozzolanic aggregate content. The lime mortars containing artificial pozzolans (cocciopesto) were coated with lime mortars containing natural volcanic pozzolans. The foreign provenance of the natural and artificial pozzolans may be attributable to the amount of trade that passed through the Roman city’s port in the 1st and 2nd centuries AD.Ministerio de Economía y CompetitividadComunidad de MadridDepto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

Provenance of construction stone from the Wall of Plasencia, Cáceres

Cuando se aborda la restauración del Patrimonio arquitectónico y se piensa en la posibilidad de llevar a cabo tareas de sustitución de materiales pétreos muy degradados, es imprescindible realizar estas actuaciones con un material muy similar, en cuanto a características petrofísicas y geoquímicas se refiere, para evitar incompatibilidades de materiales y con ello una aceleración de deterioro del monumento. La localización de las canteras que abastecieron de materia prima a un monumento es de importancia para poder abordar los trabajos de restauración y conservación del Patrimonio arquitectónico. La piedra de construcción utilizada en la Muralla de Plasencia está constituida mayoritariamente por mampuestos de granito de dos micas de carácter porfídico. Las características petrográficas, geoquímicas y petrofísicas del granito han permitido localizar canteras de las que se pudieron abastecer. Estas canteras son las que se denominan actualmente como Cantera Codillo de San Antón y la Cantera de BerrocalRestoration of Heritage Patrimony by substitution of very degraded stony materials requires very similar materials, with similar petrophysical and geochemical characteristics, so as to avoid not compatible materials and the acceleration of deterioration of the monument. The location of the quarries that supplied with raw material the monuments is very important in restoration and conservation works of Heritage Patrimony. The construction stone used in the wall of Plasencia is mainly constituted by blocks of porphyric two-mica granites. Knowledge on petrographical, geochemical and petrophyscical characteristics of granites allow locating the quarries that could supply the appropriate material for restoration works. These quarries are “Cantera Codillo San Antón” and “Cantera Berrocal”.INTROMACMATERNAS (0505/MAT/0094)MINISTERIO DE EDUCACIÓN Y CIENCIA (CSD2007-0058)Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

Characterizing the Microbial Colonization of a Dolostone Quarry: Implications for Stone Biodeterioration and Response to Biocide Treatments

Received: 7 September 2010 / Accepted: 1 February 2011 / Published online: 26 February 2011 © Springer Science+Business Media, LLC 2011This study examines the microbial colonization of three fronts of an abandoned dolostone quarry (Redueña, Madrid, Spain) exposed to atmospheric conditions for different time periods since Roman times to the present. Through scanning electron microscopy in backscattered electron mode (SEM-BSE), endolithic colonization was predominantly detected in the most recently exposed front, while in the longer exposed quarry fronts, epilithic forms of growth were most often observed. These observations were confirmed by denaturing gradient gel electrophoresis (DGGE) analysis. Based on the distribution pattern of microbial colonization in the different quarry fronts, we then established a sequence of colonization events that took place over this long time frame. Bioalteration processes related to this sequential colonization were also identified. Characterizing these sequential processes can be useful for interpreting biodeterioration processes in historic dolostone monuments, especially those affecting constructions in the area of the Redueña stone quarry. In a second experimental stage, different biocide treatments were tested on this quarry rock to find the best way to avoid the microbial colonization effects identified. Through combined SEMBSE/ DGGE analysis, the efficacy of several biocides against the microorganisms inhabiting the dolostones was assessed after 4 and 16 months treatment. In general, all treatments were effective at reducing around 80% of the lichen cover, although effects on endolithic lithobiontic communities were dependant on how well the rock surface had been mechanically cleaned prior to treatment and gradually disappeared over time.Comunidad de Madrid (España)Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu