Hydric dilation of Mount Nemrut sandstones and its control by surfactants

Hydric dilation measurements of Mount Nemrut sandstones, using a linear variation differential transformer (LVDT), were used to quantify in order to understand the effect of wetting-drying cycles on Mount Nemrut sandstones. Trials with some surfactants to inhibit swelling, resulting from the clay minerals in the structure, were investigated in order to propose some conservation treatments for the Mount Nemrut monument sandstones. The hydric dilation measurements of surfactant-treated sandstones showed some decrease in swelling. Diaminoalkine (DAA) seemed to be most successful surfactant for the inhibition of clay swelling, which is in accordance with previous studies. In this study, hydric dilation was decreased by 40% with the use of DAA. (C) 2014 Elsevier Masson SAS. All rights reserved

Investigation of atmospheric corrosion layers on historic iron nails by micro-Raman spectroscopy

In this study, some Ottoman low carbon steel nails from a 16th century brickmasonry dome of Kilic Ali Pasha Bath in Istanbul and from a 19th century stone dwelling in Phocaea Izmir were studied for their long term corrosion characteristics. Their corrosion layers were examined with a Senterra Bruker micro-Raman spectrometer and Tescan Vega model Scanning Electron Microscopy (SEM) with Inca X-Stream 2 Energy-Dispersive X-ray spectroscopy (EDX). Powdered samples scraped from the corrosion layers were studied by X-ray powder diffraction and Fourier transform infrared spectroscopy. The corrosion layer consisted of two main sub-layers, namely an 'inner corrosion layer' including a 'reaction front' and a 'transformed medium' which included the depositions from the surrounding media. Peak intensities of X-ray powder diffraction traces were not proportional to the abundance of oxides and oxyhydroxides in the corrosion layer, most probably because of their partly amorphous and nano-size nature. Inner corrosion layer and transformed medium layers were studied in detail by micro Raman spectroscopy at 532 nm, 0.2 mW, 200 s. The Protective Ability Index (PAI) of the corrosion layers were expressed as the ratio of isotropic goethite band thickness to the thickness of reaction front composed of other oxides and oxyhydroxides being magnetite, maghemite, hematite, lepidocrocite, distinguished by micro-Raman which is a unique method for phase identification. PAI was then estimated to be similar to 6-10 for 16th century nails and similar to 3 for 19th century nails. Corrosion mechanisms and PAI were concluded to be affected by compositional characteristics of artefacts and their atmospheric conditions. Copyright (C) 2016 John Wiley & Sons, Ltd

Raw material properties of some medieval mortars in Kubadabad palaces (Turkey)

Raw material characteristics of stone and brick masonry mortars in two Kubadabad palaces built in 13th century in Konya- Turkey were studied to understand medieval mortar technology of those two structures, to make comparison of the raw materials used, and to discuss their relationship with local geology and the possible raw material sources. Optical microscopy, XRD, SEM, EDX and FTIR analyses determined mineralogical and petrographical characteristics of mortars. The physical and mechanical properties of the mortars were studied by bulk density and total porosity measurements using RILEM standard test methods, uniaxial compressive strength estimations by ISRM-Point Load Tests and modulus of elasticity by ultrasonic pulse velocity measurements. Chemical analyses were carried out to determine the binder and aggregate ratios by dilute acid treatment, weight loss by heating as thermogravimetric analysis, and pozzolanic activity of fine aggregates by treatment with saturated calcium hydroxide. Particle size distribution in aggregate parts was determined by standard sieve analysis. The results have shown that the stone and brick masonry mortars of two palaces were similar in their mortar technology although they were constructed one after the other. The mortars differed in their physical and mechanical properties depending on the type of masonry they were used. The load bearing stone masonry mortars were of higher density and lower porosity in comparison to brick masonry mortars of the arches and upper structures. The binder ratios of both stone and brick masonry mortars were high, being higher in the brick one. The white lumps containing around 95 % of CaCO3 indicated the use of fat lime as binder. Abundant limestone formations in the region indicate that production of fat lime was highly probable. The coarse aggregates found as metamorphic, volcanic and sedimentary rock fragments, had well reflected the geological characteristics of the region that have contributed to the formation of Konya Plain. The fine aggregates, rich in opal-A indicated the exploration and the use of local natural pozzolanic sources derived from the weathering of volcanic rocks.Les caractéristiques des matières premières de mortiers de maçonnerie de pierres et briques, dans deux palais Kubadabad construits au 13ème siècle en Turquie-Konya, ont été étudiées pour comprendre la technologie du mortier médiéval de ces deux monuments pour comparer les matières premières utilisées et pour discuter leurs relations avec la géologie locale et les sources de matières premières possibles. Des analyses par microscopie optique XRD, SEM, EDX et FTIR ont permis de déterminer les caractéristiques minéralogiques et pétrographiques des mortiers. Les propriétés physiques et mécaniques des mortiers ont été étudiées par densité volumique et porosité totale, en utilisant les méthodes de test standard RILEM, les estimations de force de compression uni-axiale par tests de charge ISRM, le module d'élasticité par mesure de la vitesse d'impulsion ultrasonique. Des analyses chimiques ont été réalisées pour déterminer les rapports entre liant et agrégat par traitement par acide dilué, la perte de poids par chauffage comme par analyse thermogravimétrique, l'activité pouzzolanique des agrégats fins par traitement avec hydroxyde de calcium saturé. La distribution des dimensions des particules dans les agrégats a été déterminée par tamisage. Les résultats ont montré que la maçonnerie en pierre et brique des deux palais était similaire dans la technologie des mortiers même si les constructions n'ont pas été contemporaines. Les mortiers diffèrent dans leurs propriétés physiques et mécaniques en fonction du type de maçonnerie dans lequel ils ont été utilisés. Les mortiers des maçonneries en pierre de charge étaient d'une densité supérieure et d'une porosité plus faible que ceux de la maçonnerie en brique des arches et des structures supérieures. Les taux en liant des mortiers sont plus élevés dans les maçonneries en brique. Les morceaux blanchâtres contenant environ 95 % de CaCO3 indiquent l'usage de calcaire comme liant. Les nombreuses formations calcaires de la région indiquent une provenance locale probable. Les agrégats grossiers issus de roches métamorphiques, volcaniques et sédimentaires reflètent clairement les caractéristiques géologiques des formations régionales ayant contribué à la formation de la plaine Konya. Les fins agrégats, riches en opale-A indiquaient l'exploitation des sources locales de pouzzolanes.Tuncoku S. Sarp, Caner-Saltik Emine N., Hugon Paulette. Raw material properties of some medieval mortars in Kubadabad palaces (Turkey). In: Revue d'Archéométrie, n°28, 2004. pp. 109-116

The assessment of a roof drainage system for an historical building

Roof drainage systems of historical buildings no longer serving effectively under existing conditions should be repaired according to maintenance programs developed specifically for them through a study of their characteristics, discharge capacities, faults and the climatic conditions prevailing in their environs. The studies necessary for this should ideally be done using non-destructive methods. Such a study was conducted on the roof of a 13th century stone monument, "Agzikarahan", in Aksaray, Turkey, to assess its overall drainage adequacy and its potential for taking corrective action. Results showed that the roof was originally configured to provide a proper peripheral drainage system. However, it fails at present due to earlier incorrect interventions and subsequent lack of maintenance. Suggestions were made on urgent remedial interventions, preventive measures and future improvements