Durability of a ventilated stone facade: A case study of a limestone facade affected by the corrosion of the anchorage system

2020 ◽  
Author(s):  
Vera Pires de Almeida Ribeiro
Keyword(s):  
Chemical Characterization ◽  
Masonry Walls ◽  
Concrete Walls ◽  
Reinforced Concrete Walls ◽  
Correct Execution ◽  
Anchoring System ◽  
Ventilated Facade ◽  
Non Destructive

<p>The mechanical behavior of a natural stone ventilated facade is inevitably based on the correct execution of both anchoring elements, stone cladding and enclosure support, either with brick masonry walls or reinforced concrete walls. In the case studied in the present work, the origin of the damages on the facade of a building located in Lisbon has been analyzed, where stone detachments were starting to occur. This enclosure is a ventilated facade cladded with Portuguese limestone Lioz slabs. Non-destructive borescope analysis of the metallic anchoring system employed was performed, as well as X-Ray fluorescence laboratory analysis (FRX) for chemical characterization of the anchoring material. Results obtained demonstrated the problem cause on the stone facade due to incorrect metallic anchoring selection and poor execution combined with stress corrosion effect, especially for slabs with larger dimensions.</p>

Handheld Portable Energy-Dispersive X-Ray Fluorescence Spectrometry (pXRF)

2016 ◽  
pp. 362-381 ◽  
Author(s):  
Elisabeth Holmqvist
Keyword(s):  
Production Systems ◽  
Matrix Effects ◽  
Chemical Characterization ◽  
High Sensitivity ◽  
Limited Range ◽  
Energy Dispersive ◽  
Analytical Sensitivity ◽  
X Ray ◽  
Non Destructive

Handheld portable energy-dispersive X-ray fluorescence (pXRF) spectrometry is used for non-destructive chemical characterization of archaeological ceramics. Portable XRF can provide adequate analytical sensitivity to discriminate geochemically distinct ceramic pastes, and to identify compositional clusters that correlate with data patterns acquired by NAA or other high sensitivity techniques. However, successful non-destructive analysis of unprepared inhomogeneous ceramic samples requires matrix-defined scientific protocols to control matrix effects which reduce the sensitivity and precision of the instrumentation. Quantification of the measured fluorescence intensities into absolute concentration values and detection of light elements is encumbered by the lack of matrix matched calibration and proper vacuum facilities. Nevertheless, semi-quantitative values for a limited range of high Z elements can be generated. Unstandardized results are difficult to validate by others, and decreased analytical resolution of non-destructive surface analysis may disadvantage site-specific sourcing, jeopardize correct group assignments, and lead to under-interpretation of ceramic craft and production systems.

Beyond Death: Forensic Investigations of pre-Columbian Mummies from the Tarapacá Valley, Chile, Using Variable Pressure SEM and Raman Spectroscopy

2007 ◽  
Vol 15 (6) ◽  
pp. 6-11 ◽  
Author(s):  
S.V. Prikhodko ◽  
C. Fischer ◽  
R. Boytner ◽  
M. C. Lozada ◽  
M. Uribe ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Chemical Characterization ◽  
Quantitative Information ◽  
Mortuary Practices ◽  
Variable Pressure ◽  
Scientific Investigations ◽  
Non Invasive ◽  
Archaeological Materials ◽  
Non Destructive

Variable pressure scanning electron microscopy (VPSEM) coupled with other non-destructive analytical methods, such as energy dispersive (EDS) and Raman spectroscopy (RS) offers new capabilities for non-invasive imaging and chemical characterization of archaeological materials. This article underlines the application of VPSEM-EDS-RS on bioarchaeological specimens of pre-Columbian mummies from the Tarapacá Valley in northern Chile. The aim of the scientific investigations is to identify nonanatomical features and to provide qualitative and quantitative information at molecular levels, complementing the morphological record from studies in physical anthropology, in an effort to understand mortuary practices in the Tarapacá Valley and the effects of the burial environment in the preservation of mummified human remains.

Chemical characterization of submicron aerosol in summertime Beijing: A case study in southern suburbs in 2018

Chemosphere ◽  
2020 ◽  
Vol 247 ◽  
pp. 125918
Author(s):  
Tianzeng Chen ◽  
Jun Liu ◽  
Yongchun Liu ◽  
Qingxin Ma ◽  
Yanli Ge ◽  
...  
Keyword(s):  
Chemical Characterization ◽  
Submicron Aerosol

scholarly journals Mechanical and Typological Characterization of Traditional Stone Masonry Walls in Old Urban Centres: A Case Study in Viseu, Portugal

Buildings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 18 ◽  
Author(s):  
José Carlos Domingues ◽  
Tiago Miguel Ferreira ◽  
Romeu Vicente ◽  
João Negrão
Keyword(s):  
Safety Evaluation ◽  
Stone Masonry ◽  
Masonry Walls ◽  
Masonry Buildings ◽  
Existing Buildings ◽  
Urban Center ◽  
In Situ Characterization

Essential for any intervention in existing buildings, a thorough knowledge of both structural and material characteristics is even more important in the case of traditional stone masonry buildings, due both to the variability of this technology’s properties and the degradation buildings might have sustained. In Portugal, a number of in situ and laboratory experimental campaigns has allowed us in recent years to expand the knowledge on the mechanical properties of stone masonry walls. Nevertheless, the existence of different wall typologies built with the same material necessitates that this characterization takes into account the various regional constructive cultures. This paper presents the results obtained through an in-situ characterization campaign carried out in the old urban center of Viseu, for which there is no information available in the literature. Granite stone masonry walls of two different buildings were analyzed and characterized considering their geometrical and material features, contributing to the identification of stone masonry typologies present in the city’s old urban center. Flat-jack testing yielded resistance and deformability parameters to be used both in safety evaluation and intervention design. The properties obtained can be said to be consistent with those deriving from other experimental campaigns, conducted in granite walls of different typologies, throughout the country. Simultaneously, relevant conclusions about the use of flat-jacks to characterize this type of stone masonry were drawn.

scholarly journals Sonic and Impact Test for Structural Assessment of Historical Masonry

2019 ◽  
Vol 9 (23) ◽  
pp. 5148 ◽  
Author(s):  
Alessandro Grazzini
Keyword(s):  
Impact Test ◽  
Structural Parameters ◽  
Historical Masonry ◽  
2016 Amatrice Earthquake ◽  
The Impact ◽  
Santa Maria ◽  
Non Destructive ◽  
Non Destructive Techniques

Diagnostics is a very important tool of knowledge in the field of historical buildings. In particular, non-destructive techniques allow to deepen the study of the mechanical characteristics of the historical walls without compromising the artistic value of the monumental building. A case study of the use of sonic and impact tests was described, performed using the same instrumented hammer, for the characterization of the masonry walls at the Sanctuary of Santa Maria delle Grazie at Varoni, one of the churches damaged in the 2016 Amatrice earthquake. Sonic tests showed the presence of a discontinous masonry texture, as well as confirming the ineffectiveness of the strengthening work made by injections of lime mortar. The impact test allowed us to obtain the elastic modulus of the omogeneous stones of the masonry. The results obtained from the non-destructive techniques were confirmed by the flat jacks test carried out on the building, confirming the great potential of the non-destructive diagnostics suitable for analyzing important structural parameters without affecting the preservation of historical masonry structures.

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