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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Archaeometrical Investigation Of Some Seljuk Plasters

Caner, Evin 01 January 2003 (has links) (PDF)
The aim of the study was to investigate Seljuk Plasters used in some of their royal administrative or residential buildings from a viewpoint of their raw materials and technological characteristics. Some Byzantine Plasters of the same period were also investigated to make comparison. Plasters from some historic structures in the archaeological sites namely / Alanya Castle, Kubadabad Palaces, Syedra Archaeological Site, Aspendos Amphitheatre, Selinus Archaeological Site-Sekerhane K&ouml / sk and Hasbah&ccedil / e were examined. In a series of examination basic physical properties of the plasters as bulk density, porosity, water absorption capacity and water vapour permeability were obtained. The results indicated that plasters are low dense and high porous materials and having good breathing property. Mechanical properties of the plasters were expressed by the modulus of elasticity (Emod) values which were obtained from ultrasonic pulse velocity measurements. The Emod of the plasters being in the range of 1.0 to 5.6 Gpa show that they have enough mechanical strength comparable to historic mortars and bricks. Raw material composition and mineralogical properties of plasters were determined by combined interpretation of several types of analyses such as chemical analyses, particle size distribution of aggregates, petrographic analyses of thin sections by optical microscopy, scanning electron microscopic analyses of cross sections coupled with EDX for image analyses and semiquantitative elemental analyses, X-ray powder diffraction analyses for the determination of mineral phases, thermogravimetric analyses and FTIR analyses. Binder used in all plasters was found to be lime with amount in the range of 53.8-96.8% as CaCO3. The main minerals of aggregates are quartz, calcite (limestone), dolomite and opal-A. Regarding particle size distribution of aggregates it was possible to classify them into fine, coarse and mixed aggregates having rather high pozzolanicity. Study on decorative and red zigzag patterned plasters indicated presence of haematite as the source of red pigment. Study on green colored plaster also indicated presence of iron containing mineral with lower oxidation state. The Seljuk and Byzantine Masonries chosen are still surviving buildings that their plasters should be of good quality. In fact, this study approved their quality which may be due to the presence of opal-A and dolomite.
2

Traditional lime mortar and plaster : Reconstruction with emphasis on durability

Balksten, Kristin January 2007 (has links)
Lime mortar and plaster have been investigated with the aim to improve the knowledge on how to make them as durable as before the cement technology was developed. The background was the durability problems experienced for newly produced lime plaster on the medieval churches on the island of Gotland, Sweden. In some cases the new lime plaster façades showed severe frost damages after only one winter. Although the lime was burnt and produced according to old local traditions, the lime mortar was still mixed and worked onaccording to methods developed for lime-cement mortar. This often led to a very porous lime plaster with a lime shell in the surface and such a plaster has been shown to be sensitive to frost expansion. Field studies were combined with laboratory studies of thin section specimens. Optical microscopy and scanning electron microscopy have been important analytical methods showing the porosity and the structure of the binder and aggregate materials. The investigations have been carried out on both historic and on newly made reference mortar and plaster. The field studies were carried out mainly on Gotland, using local materials. The influence of the raw materials, i.e. lime, aggregate and blending ratio was investigated. The focus has been on the workability of the fresh mortars as well as the pore structure of the carbonated plaster. The craftsmanship, meaning mixing and application of mortar and working the plaster surface, was studied in order to clarify its final pore structure. The pore structure in a material determines many of its technical properties, such as moisture transportation, compressive strength, permeability and frost resistance. All these properties are closely connected to the durability of the mortar and plaster. The permeability of the plaster has an impact also on the durability of the covered construction materials. Behind low-permeable plasters made with hydraulic binder, examples of extensive damages of rotten wood and leached lime have been shown. The investigations have shown the importance of choosing a mortar adjusted to the building construction. They also showed the importance of choosing a blending ratio adjusted to the specific binder and sand used in order to get a mortar with a suitable pore structure and good durability. It has also shown the importance of knowing when and how to work on the plaster surface in order to obtain a homogenous material that is well receptive for lime wash and has a good frost resistance. The combination of all the investigations has led to a method for reconstructing historic mortar and plaster with good durability.
3

Karbonatisering av modernt kalkputs med hydraulisk inblandning / Carbonation of modern lime mortar whith hydraulic mix

Hossainy, Shokoufeh January 2022 (has links)
Kalkbruk har använts i tusentals år som byggnadsmaterial i byggkonstruktioner.Senare, under 1800-talet, började en variant av hydraulisk kalk, kallad vattenkalk, att användas. Det hydrauliska kalkbruk som används idag i byggnadskonstruktioner såsom fasadmurning, putsning, fogning av murverk har blivit mer vanligt att använda i stället för cementbruk, eftersom det finns fler fördelar med kalkbruk som har hydraulisk inblandning än med det cementbaserade bruket. Kalkbruk används särskilt till renovering av äldre byggnader där kalk eller hydrauliska kalkbruk sedan tidigare har använts. Det hydrauliska kalkbruket utvinns från kalksten men den hydrauliska kalk som bränns av oren kalksten kallas naturligt hydraulisk kalk och tillverkas av Saint-Astier i Frankrike. Kalken har inga hydrauliska tillsatsmedel som cement, gips, flygaska eller puzzolana material. Enligt SS-EN 459–1:2015 klassas den naturliga hydrauliska kalken efter hållfasthet, och tillverkas i tre klasser: NHL 2, NHL 3,5 och NHL 5.Naturliga hydraulisk kalkbruken har för- och nackdelar, Produktens fördelar avses av de som använder bruket överväga nackdelarna. NHL-bruk passar bättre i fuktiga miljöer, det kan återanvändas, är miljövänligt, rent och naturligt, tål mer påfrestningar och driftstiden är mindre. Bakgrunden till arbetet är att NHL-bruks användning har blivit allt vanligare under de senaste decennier vid renovering av äldre kalkputsade byggnader. Väderförhållande och temperatur är av stor betydelse för att ha ett hållbart resultat inom kalkputsarbetet och således kan orsaka en viss försening i tidplaner och byggtider. Emedan nya metoder ska utreda och utvärderas för att få det optimala resultatet.Litteraturstudier, laboratorietester och intervjuer har använts för att kunna nå examensarbetets mål. Flera små tester har gjorts för att undersöka karbonatiseringsprocessen under olika väderförhållandet. Testerna visar att det naturliga kalkbruket karbonatiserar bättre och snabbare i en fuktig miljön, vilket passar det klimat som råder i Norden och i kustklimat. Det naturliga hydrauliska kalkbruket är dock ett material som kräver mer erfarenhet för att kunna uppnå bästa resultat för detta ändamål. Att vädret har stort betydelse för karbonatiseringsprocessen är ett resultat som framkommit i tidigare studier och forskning, vilket också de tester som utförts under detta arbete visar. Arbete med hydrauliska kalkbruk bör därför ske under perioder som passar kalkputsarbetet för att det ska hinna karbonatisera innan det riskerar att utsättas för påfrestning. En lämplig period är därför maj till oktober som den bästa perioder för kalkputsarbete.Naturliga hydrauliska kalkbruk utvecklas kontinuerligt, vilket kan bidra till att de kan ersätta det cementbaserade kalkbruket i framtiden utan några negativa konsekvenser såsom frostsprängning och låg hållfasthet. / The aim of the work was to analyze the carbonation of modern lime plaster with hydraulic mixing. Requirements for a certain carbonation can cause delays in schedules and construction time. The hydraulic lime mill is obtained from limestone, while the hydraulic lime burned by crude limestone is called natural hydraulic lime, which is manufactured by Saint-Astier in France. the lime has no hydraulic additives such as cement, plaster, fly ash or puzzolana materials. Natural Hydraulic lime mills fit better in the humid environment, it can be reused, is environmentally friendly, is clean and natural, can withstand more stress and the operating time is less. During the work, a study visit was made to an ongoing work process at Elin Wägnerskolan in Växjö, which Karlssons fasad AB had taken over the restoration responsibility. Interviews were conducted with one of the players at Målarkalk AB, which is one of the largest suppliers in the lime industry and project manager at Karlssons Fasad AB. Several small tests have been done to see the carbonation process under different weather conditions. The tests show that natural lime farming carbonates better and faster in a humid environment, which suits the Nordic countries and coastal environments. Natural hydraulic lime mills are well suited to replace cement-based mortars in the future without any negative impact.

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