Parameterisation of Gypsum Mortar for Alternative Structural Consolidation of Traditional Floors
Fernando Vegas,
Camilla Mileto,
Valentina Cristini,
José Ramón Ruiz-Checa
Issue:
Volume 2, Issue 4, August 2013
Pages:
48-52
Received:
23 July 2013
Published:
20 August 2013
Abstract: The role of gypsum as a construction material in vernacular architecture, not only as an auxiliary material, but also for enhancing structural features in floors and even in pillars, has had a long-standing history of application in different traditional buildings in some parts of Spain. The authors have identified the main properties of this material from a structural point of view by experimenting in situ on traditional gypsum jack arch floors as part of the project “Structural consolidation of traditional floors with compression layers of gypsum with fibres” (UPV/PAID-05-11/2893). Several traditional and commercial compression layers for traditional floors were made with different proportions of water in the mixture to parameterise its use and achieve the ideal thickness and dosage. In this research, the authors have used both traditional dosages and experimental mixtures containing fibres, which were monitored by standard tests of surface hardness and resistance to compression and flexion. This work presents the main results of the properties of the different types gypsum obtained in the laboratory analysis phase as an alternative option for the structural reinforcement of traditional floors.
Abstract: The role of gypsum as a construction material in vernacular architecture, not only as an auxiliary material, but also for enhancing structural features in floors and even in pillars, has had a long-standing history of application in different traditional buildings in some parts of Spain. The authors have identified the main properties of this mater...
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Changes in Internal Structure of Bronze and Iron over Time at Ambient Temperature
Jaroslav Fiala,
Jaroslav Pavelka,
Jiří Kříž,
Martin Hložek,
Pavel Hušťák
Issue:
Volume 2, Issue 4, August 2013
Pages:
53-58
Received:
6 July 2013
Published:
20 August 2013
Abstract: This study analyzes changes in the inner structure of metals (bronze and iron) resulting from aging and creeping processes. A remarkable disproportion was noticed during hardness analyses of original metal objects from archaeological finds and replicas likely made in the same way as the originals. The mechanism of such long-term changes at ambient temperature remain unknown. We examined the azimuthal (lateral) diffraction line profile, which includes the size, number and shape of individual diffraction spots comprising a discontinuous diffraction line. By x-ray analysis, all of the original bronze and iron artifacts were proven coarse–grained; coherent areas (mosaic blocks) were larger than 10 μm. The original structure of objects produced by the forging of sponge iron must have been much more fine–grained. The measurements revealed that the mechanism responsible for the change in the structure of forged artifacts over time is spontaneous recrystallization. We found that spontaneous recrystallization occurs much more quickly than usually expected at ambient temperature. We derived formulas explaining how the mechanism of relaxation changes on cooling from high to ambient temperature. Some low-energy mechanisms are blocked at elevated temperatures but released at ambient temperature. The activation energy of such mechanisms is much lower than the activation energy of relaxation processes at elevated temperatures. Our findings can be usefully exploited when monitoring processes that degrade the structure of a material in the course of its service.
Abstract: This study analyzes changes in the inner structure of metals (bronze and iron) resulting from aging and creeping processes. A remarkable disproportion was noticed during hardness analyses of original metal objects from archaeological finds and replicas likely made in the same way as the originals. The mechanism of such long-term changes at ambient ...
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