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An Investigation Of Strengthening Of Historical Masonry Constructions By Steel SkeletonKucukdogan, Bilge 01 August 2007 (has links) (PDF)
Historical masonry structures are important cultural assets which reveal the social, archaeological, aesthetic, economical, political, architectural and technical features of their times. Within the course of the time, the structures have been exposed to the destructive effects of the nature and the man. Some has been able to survive somehow and others were totally ruined. Most of the remained structures are in vulnerable condition to upcoming effects and for the continuity of their presence, structural strengthening applications are needed. A variety of applications are used with different levels of respect to original fabric and different extents of intervention within the principles of international charters that regulate the intervention on historical monuments.
In this study, a method of strengthening for the historical masonry constructions is developed in a general sense by the use of steel skeleton systems. In the proposed methodology, it is aimed to approach the intact structural conditions as much as possible in the strengthened structure. For the study a 3D model is created to compare the behaviors of the intact and the modified structure. In the modified model some structural elements are replaced by the steel skeleton system as a strengthening application. The behavioral investigation of the two models is performed in the finite element platform. Finally, it is certified that this methodology successfully efficient in approaching the original intact condition of the structure under concern as well as complying with the restoration principles.
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Evaluating CFRP-Masonry Bond Using Thermal ImagingRoss, Joseph Christopher 01 January 2013 (has links)
This study presents results from non-destructive testing to evaluate the degradation of the CFRP-masonry bond using thermal imaging. The goal of the research was to identify locations where there was evidence of bond deterioration that could subsequently be verified through destructive pull-off testing.
Four full-scale masonry walls were built outdoors at the University of South Florida in 1995 to evaluate the effectiveness of CFRP for repairing settlement damage. Two of the settlement-damaged walls were repaired using single layer, commercially available unidirectional CFRP systems that used Tonen (wall 3) and Henkel (wall 2) epoxies. These two walls were the subject of this investigation.
Before non-destructive tests were initiated, historical site data on temperature, humidity and rainfall variation was compiled. Over seventeen years, the walls experienced ambient temperatures as high as 98°F and as low as 25°F. The average rainfall in Tampa is about 34 inches and the annual average high humidity is around 87%#37;. Because of the high temperature and humidity, the CFRP-masonry bond was exposed to a particularly aggressive environment.
Three types of thermal evaluation were carried out: thermocouple monitoring and both passive (solar) and active (localized heating) infrared thermal imaging. Twenty-four thermocouples were used to observe the spatial variations in temperature on the wall. Data showed that the surface temperatures of the wall are uneven with one end being hotter than the other. Measurements indicated that the wall temperatures went as high as 103°F during the week of data collection in late March and early April of 2012. In contrast, the highest ambient temperature over the same period was 92°F. The high temperature experienced by the wall is below the glass transition temperature for the epoxies, which ranges from 140°F to 180°F.
A FLIR Tau 320 thermal imaging camera was used to identify localized de-bonding. Solar radiation heated the walls and the goal of thermal imaging was to detect hot spots which are indicative of de-bonding. Although this technique is ideal for exterior applications, initial attempts were unsuccessful. Once de-bonds were located by sounding, the camera was capable of confirming two hot spots on wall 2.
A thermal scanner built by the university from a series of ten Omega OS137 thermal sensors was used to obtain more complete thermal images of the walls. This scanner had a heating element which supplied heat and allowed for active thermography. The scanner detected 16 hot spots not seen with the thermal camera. Ten of the twelve spots on wall 2 are concentrated on a region of the wall which experienced the highest daily changes in temperature, which indicates that higher thermal and environmental cycling has caused greater de-bond.
Based on the number of hot spots found using both active and passive thermography the Tonen epoxy is performing better than the Henkel epoxy. In general, the bond has endured; however, there are a few localized areas that have de-bonded. Pull-off tests are recommended on walls 2 and 3. Five locations in regions suspected to have poor bond and five locations in regions suspected to have good bond are identified for each wall.
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Statická rekonstrukce barokního vinného sklepa / Static reconstruction of the baroque wine cellarKešiar, Szabolcs January 2018 (has links)
The diploma thesis is focused on the design of structural support and construction modifications of a baroque wine cellar, which is part of a double-storeyed house. The first part deals with the statical analysis and structural support of a masonry barrel vault, which was loaded with a new building. The second part deals with the reconstruction of the double-storeyed object, which is in a state of disrepair with heavily developed cracks. The thesis contains a technical report, analysis of statics, drawing documentation and the work progress. The calculation of internal forces were executed by the software Scia Engineer 2017. The drawing documentation contains a formwork and reinforcement drawing, maping of cracks, leading of tensions in the walls and vault including of floor plans, sections and elevations, production plans of base plates and deviators, reinforcement drawing of concrete bond beam and finally the construction process of upper construction.
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