Wyniki wyszukiwania - BazTech

1

Ocena wytrzymałości murów na podstawie badań próbek cegieł i zapraw pobranych z konstrukcji

Matysek Piotr

Materiały Budowlane

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2023

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nr 12

1--4

PL

W artykule przedstawiono metodę szacowania wytrzymałości murów w budynkach istniejących na podstawie badań próbek cegieł i zapraw pobranych z konstrukcji. Metoda ta polega na adaptacji zależności potęgowej podanej w normie Eurokod 6. Dzięki zaproponowanym rozwiązaniom możliwe jest określenie wytrzymałości na ściskanie również murów na zaprawie o małej wytrzymałości. Opracowana metoda uwzględnia wpływ na szacowaną wytrzymałość muru takich czynników, jak rozrzut wytrzymałości cegieł i zapraw oraz liczba próbek, która została użyta do oceny cech wytrzymałościowych materiałów murowych.

EN

In the article a method for estimating the masonry strength in existing buildings based on tests of brick and mortar samples taken from the structure is presented. This method adapts the power function given in Eurocode 6. Thanks to the proposed solutions, it is possible to also determine the compressive strength for masonry with low-strength mortars. The developed method takes into account the influence on the estimated masonry strength of such factors as the dispersions of the strength of bricks and mortars and the number of samples used to assess the strength characteristics of masonry materials.

2

Wpływ zasolenia na kinetykę wysychania zabytkowej cegły

Bułka A.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

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2017

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z. 108

15--16

EN

The article present the kinetics of drying of historical bricks. Experiment was measured loss of moisture over time in samples historical bricks. A typical drying curve was obtained which are first stage of the line and then decreases according to the function.

3

Technika konstrukcji średniowiecznych murów ceglanych na ziemiach polskich

Feduszka J.

Ceramika Budowlana

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2011

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nr 3

27-28

PL

Historycy techniki i historycy architektury, a także archeolodzy opierają swoje spostrzeżenia na temat techniki murarskiej w średniowieczu zasadniczo na luźnym zbiorze wiadomości opartych na obserwacji powierzchni murów. Średniowieczny mur ceglany wykonywano ze zwykłej cegły, przede wszystkim zendrówki i cegły glazurowanej. Ta ostatnia była jednak droższa, ze względu na skomplikowaną produkcję. W XIV i XV wieku m.in. w Małopolsce wraz z rozpowszechnieniem się wątku gotyckiego w układzie cegieł, zaczęto stosować pełnoceglane przekładki w miąższu muru, który nie był już wypełniony, jak wcześniej zaprawą i gruzem, ale pełną cegłą. Jako materiału wiążącego używano zaprawy wapiennej, niekiedy odpowiednio spreparowanej gliny. Wapno na zaprawę wypalano w piecach, często w tych samych, w których wypalano i cegłę. Wapienniki w średniowieczu, w przeciwieństwie do innych epok, znajdowały się na placu budowy, lub w bezpośrednim jego sąsiedztwie.

EN

Historians of art and architectural historians, and archeologists base their findings on the masonry techniques in the Middle Ages essentially a loose set of messages based on the observation of the surface of the walls. Medieval brick wall bricks were made from ordinary, mainly zendrówki glazed and brick. The latter, however, was more expensive, due to the complicated production. In the fourteenth and fifteenth century, including in Małopolska the rise of the Gothic thread in the system of bricks, began to use spacers in the flesh pełnoceglane wall that was not already completed, as previously mortar and rubble, but full of bricks. As the binding material used lime mortar, sometimes appropriately crafted clay. Lime for mortar fired in kilns, often in the same, which fired and brick. Lime in the Middle Ages, in contrast to other eras, were on site, or in its immediate vicinity.

4

Uwagi o szacowaniu wytrzymałości murów zabytkowych na podstawie wytrzymałości cegieł i zaprawy

Matysek P.

Materiały Budowlane

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2010

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nr 9

44-45

5

Warsztat budownictwa ceglanego księcia Władysława Opolskiego i jego pojawienie się w Kaliszu (schyłek XIV wieku). Obraz na podstawie analizy wymiarów cegły

Żemigała M.

Kwartalnik Architektury i Urbanistyki

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2002

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T. 47, z. 4

410-417

EN

King Kazimierz the Great built the castle in Kalisz as part of a sequence of municipal defensive facilities in the northern part of the town, next to Toruńska Gate. During the Middle Ages this four-wing and four storey edifice contained an inner courtyard and was surrounded by a moat. The mediaeval castle burned down in 1537, and was destroyed by fire to such an extent that it was never totally rebuilt. In 1985-1987 archaeological studies of the castle ruins unearthed the foundations of a gate house, located in the former southern wing. It was discovered that the gate had been redesigned already during the Middle Ages. Its state, documented during the excavations, indicates that it had been destroyed by fire, but not in 1537. Presumably, the gate was damaged in 1656 and it certainly functioned in 1564 and 1628, as testified by written sources. The lowering of the threshold of the continuous footing of the gate house and the introduction of a cellar into the foundations had been connected already earlier with changed access to the castle. The new technical solution involved the manner of raising the drawbridge, and consisted of a counterweight. Such a device had appeared in Western Europe already in the course of the fourteenth century, and possibly even earlier. Up to now, the bridge in Kalisz had been ascribed a wide chronological range. Terminus post quern was defined by the time of the construction of the castle - between 1336 and 1343, while terminus ad quem coincided at the latest with the destruction of the gate in 1656. The article intends to establish a more precise date of installing the counterweight in the castle drawbridge. The first option was a dendrochronological study of beams in the gate crossing, and the second was an attempt at dating based on measurements of the brick used for facing the breach in the gate house foundation, executed for the purpose of building a drawbridge outfitted with a counterweight. The author chose the latter approach. Only a single spot was discovered in the examined ruins in which bricks were connected with the brick castle - the outer part of the gate house ground floor and the face of the outer cellar walls. An analysis of the finding led to a differentiation between the bricks of the original fragments and the secondary supplements of the face into two groups: older A and repair B. Counterparts of those sets were found in the castle in Bolesławiec on the Prosna - group B bricks, identified with the redesigning of the castle during the 1380s by Duke Władysław Opolczyk. This is the brick used during the expansion of the castle, placed on top of the original defensive wall from the time of Kazimierz, and the brick from the freestanding octagonal tower. Sets very similar to B group brick from Bolesławiec were found in the town wall in Byczyna, located in Opole (Silesia), some 10 kms from Bolesławiec, and in the face of a castle tower in Ostrzeszów. It is worth stressing that all three constructions were situated in terrains incorporated into the duchy ruled by Władysław Opolczyk: Byczyna - in the duchy of Opole, Bolesławiec - in the region of Wieluń (governed by Opolczyk from 1370 to 1401), and Ostrzeszów in the region of Ostrzeszów, which belonged to the duke of Opole probably from 1375 to 1393. The similarity between the brick from the Bolesławiec "workshop" of Władysław Opolczyk and the brick from the mediaeval constructions in Kalisz was probably not accidental. It is so considerable that the author hazarded a hypothesis claiming that at the turn of the fourteenth century Kalisz found itself within the range of the construction workshops used by the duke of Opole not only in the region of Opole itself (Byczyna), but also in the lands of Wieluń (Bolesławiec) and Ostrzeszów (Ostrzeszów) during the 1380s and the early 1390s. Presumably, the construction "workshop" of the duke of Opole could have made its way to royal lands only after Władysław Jagiełło regained the regions of Wieluń and Ostrzeszów in an expedition waged against Opolczyk in 1393. According to Długosz, Jagiełło captured castles in Olsztyn, Krzepice, Bobolice, Brzeźnica, Wieluń, Ostrzeszów and Grabów on the Prosna. The castle in Bolesławiec on the Prosna was the only one which he did not seize immediately, but besieged, albeit unsuccessfully. Not until the death of Władysław Opolczyk did his widow and sons surrender the castle to the monarch (1401). Apart from the mentioned brick measurements there are also two other categories of sources capable of casting more light. One is the archaeological stratigraphy of the gate-house foundation, indicating that the gate-house cellar existed already prior to the mid-fourteenth century. This assumption is evidenced by findings of coins between the floor beams in the crossing (a Toruń shilling from the time of Kazimierz Jagiellon, 1454-1456, and an unidentified, damaged Teutonic Order coin). On the other hand, written sources have provided two types of information. The privilege issued by Władysław Jagiełło in 1418 contains direct mention of defensive investments; in it, the king permitted the town to conduct free trade and entitled the Town Council to collect market charges, subsequently used for financing the preservation and conservation of the defensive city walls. The second possibility was royal initiative. Władysław Jagiełło who was a frequent visitor in Kalisz, was aware of the degradation of the local defensive walls and up to 1418 personally paid for their upkeep. The content of the document from 1418 indicates that already prior to the issuing of the privilege the town walls had to be repaired, and possibly had already been mended. Such an initiative would have called for financial sources other than the normal revenue of the town. Every researcher examining bricks analyses their size and notices their changeability. These two features can be identified with the progress of time, sometimes with localisation, and in other cases with the investor. All initial premises for further detailed studies are hypothetical. Without forejudging the possibility of generalising the individual examined phenomenon, namely, the distinct similarity between group B bricks from the castle in Bolesławiec on the Prosna and group B bricks from Kalisz Castle, the author believes that in this particular instance an analysis of similarity based on measurement led to a positive conclusion. The author is inclined to place the date of the construction of the new drawbridge cellar in Kalisz Castle in the years immediately after 1394, and to connect it with the activity of the building workshops which during the 1380s developed under the rule of Władysław Opolczyk in the lands of Wieluń and Ostrzeszów, and which at the time of the reign of Jagiełło could have reached Kalisz already as royal workshops. A study of the sizes of the brick, applied for the purpose of stratifying examples of mediaeval brick architecture is, as has been said in the introduction, a controversial method. Nonetheless, in the opinion of the author, researchers dealing with architecture cannot ignore it.