3 research outputs found
Selected Aspects of the Structural Analysis of the North Dome in the "Four Domes Pavilion"/ Wybrane Aspekty Analizy Konstrukcyjnej Kopu艂y P贸艂nocnej W Pawilonie Czterech Kopu艂
Powszechnie wyst臋puj膮c膮 na ca艂ym 艣wiecie form膮 przekry膰 historycznych jest kopu艂a, kt贸ra mo偶e by膰 realizowana m.in. na rzucie ko艂a, elipsy czy o艣mioboku. Geometria kopu艂y (rzut, wyniesienie oraz grubo艣膰) wp艂ywa na rozk艂ad napr臋偶e艅 w konstrukcji i mo偶e by膰 decyduj膮cym czynnikiem wp艂ywaj膮cym na propagacj臋 rys. Przedmiotem pracy jest Pawilon Czterech Kopu艂 we Wroc艂awiu, kt贸ry powsta艂 wg projektu Hansa Poelziga w 1913r. Analiza dokumentacji archiwalnej wykazuje, i偶 wszelkie zmiany jakich si臋 podejmowano w trakcie realizacji prac by艂y wynikiem: braku czasu, op贸藕nie艅 w wykonaniu oceny statycznej, przekazaniu rysunk贸w projektowych w nieodpowiedniej skali oraz prowadzenia prac budowlanych w zimie. Efektem powy偶szych dzia艂a艅 jest niedostateczne zbrojenie kopu艂y, kt贸ra uleg艂a uszkodzeniom w formie p臋kni臋膰 po艂udnikowych i r贸wnole偶nikowych od strony zewn臋trznej i wewn臋trznej. W wyniku przeprowadzonej analizy konstrukcyjnej przy u偶yciu Metody Element贸w Sko艅czonych (MES) podj臋to decyzj臋 o wzmocnieniu przekrycia przy u偶yciu siatek z w艂贸kien w臋glowych w systemie FRCM oraz wzmocnienie pier艣cienia g贸rnego przy u偶yciu siatek z w艂贸kien P.B.O. w matrycy mineralnej
New Ceramic Tiles Produced Using Old Technology Applied on Historic Roofs—Possibilities and Challenges
In the case of historic buildings, especially those under protection, it is important to replace elements of the roof covering, while maintaining current technical standards, to meet the requirements of the conservator. The authors of the article present alternatives to commonly used solutions, based on their experience with replacing historic building roofing with ceramic tiles made according to the production and firing technology of the nineteenth century. They emphasize that the correct/specialized restoration of existing tiles in a building makes it possible to preserve and reuse them, which is in line with the principles of historic preservation. However, due to the preservation of the roof tiles, it is not always possible to revitalize them. As a solution to the problem, the use of clay roof tiles manufactured according to 19th-century firing technology, including handmade methods, is presented, which preserves the geometry of the historic roof tiles. The approach presented by the authors meets both the requirements of conservation theory and the building standards for roofing elements. Although it is much more expensive than the solutions currently commonly used that result from modern technical requirements and tile-manufacturing technology, in the case of objects of significant cultural heritage, it is a solution that meets modern technical requirements while not compromising the original appearance of the monument
Attempts to Improve the Subsurface Properties of Horizontally-Formed Cementitious Composites Using Tin(II) Fluoride Nanoparticles
This article presents studies that were performed in order to improve the subsurface properties of horizontally-formed cementitious composites using tin(II) fluoride nanoparticles. The main aim of the study was to solve the problem of the decrease in subsurface properties caused by mortar bleeding and the segregation of the aggregate along the height of the overlay. The article also aims to highlight the patch grabbing difficulties that occur during the process of forming horizontally-formed cementitious composites. Four specimens were analyzed: one reference sample and three samples modified with the addition of 0.5, 1.0, and 1.5% of tin(II) fluoride nanoparticles in relation to the cement mass. To analyze the mechanical properties of the specimens, non-destructive (ultrasonic pulse velocity) and destructive tests (flexural tensile strength, compressive strength, abrasion resistance, pull-off strength) were performed. It was indicated that due to the addition of the tin(II) fluoride, it was possible to enhance the subsurface tensile strength and abrasion resistance of the tested cementitious composites. To confirm the obtained macroscopic results, the porosity of the subsurface was measured using SEM. It was also shown that the addition of the tin(II) fluoride nanoparticles did not reduce its flexural and compressive strength. The results show that horizontally-formed cementitious composites with the addition of 1.0% of tin(II) fluoride nanoparticles in relation to the cement mass obtained the most effective mechanical performance, especially with regard to subsurface properties