Pregledni rad
Structural Renovation of Immovable Cultural Assets of Krapina-Zagorje County and Conservation Principles
Viki Jakaša Borić
; Ministarstvo kulture i medija RH, Uprava za zaštitu kulturne baštine, Konzervatorski odjel u Zagrebu
Anja Radelic
orcid.org/0000-0002-5648-2972
; Ministarstvo kulture i medija RH, Uprava za zaštitu kulturne baštine, Konzervatorski odjel u Zagrebu
Sažetak
This paper elaborates the structural rehabilitation and strengthening of immovable cultural assets in the Krapina-Zagorje County that were damaged in the 2020 earthquakes, viewed through the lens of conservation principles and conditions aimed at preserving their monumental values, identity features and authenticity.
Although the assets were moderately damaged, it was necessary to carry out extensive interventions in order to improve their overall seismic resistance, which required the application of various reinforcement systems. These included strengthening the foundations with a reinforced concrete ring and grouting, installing steel anchors to connect and strengthen the wall joints, applying FRCM systems on wall surfaces and vaults’ extrados to strengthen and stiffen them, applying reinforced concrete tie beams in the cornice areas along the entire perimeter of the building, partially replacing the wooden roof structure and adding wooden and steel reinforcement elements, and installing reinforced concrete slabs, steel lamellae or spatial structures within the volume of the towers.
In this context, the implementation of conservation principles aimed at preserving monument properties was both intensive and crucial. Particular emphasis should be placed on the importance of conservation and restoration research and the valorization of the identified historical layers, which served as the basis for developing conservation guidelines for each individual building. These were used to manage the aforementioned interventions in order to preserve architectural and structural elements, historical decorative plasters and wall paintings, historical floors and all other elements of their historical interior furnishing. Special consideration should be given to the method of application of the FRCM system, which was mostly used on facade walls where historical decorative plasters were either absent or only smaller fragments had been preserved. On the vaults, the system was applied on the outer surfaces (extrados) in order to avoid historical decorative plasters and wall paintings. For the same reason, nearly all interventions in the interior were strictly localized. However, this work also employed various methods to protect and preserve historical layers. For example, during the installation of steel tie rods and anchors on walls with valuable wall paintings, sections of plaster with wall paintings were transferred from the drilling spot (a procedure known as stacco a massello), so that these sections could later be returned to their original places through the restoration process. Structural cracks in areas that contained wall paintings were rehabilitated by “stitching” using crossed anchors, without “chasing” or stripping plaster, with careful micro-grouting and applying Japanese paper for protection. Ahead of any intervention that threatened or required the removal of decorative wall paintings, the paintings were traced onto tracing paper for potential reconstruction. If possible, certain interventions were simply omitted or repositioned to less problematic areas in some situations. Several wall paintings discovered on the facade were preserved by complete exclusion from any invasive interventions.
Since floor coverings, together with wall paintings, significantly enhance the overall impression of the interior and ambiance, often achieving a high aesthetic level through their quality and design, special attention was devoted to their preservation and presentation. If reinforcement interventions could not be avoided in these areas of the interior, specialized documentation methods were employed to facilitate the return of the stone floor slabs to their original position. The process involved architectural recording of the entire raster and numbering of each slab, alignment with historical floor elevations, and replacement of worn and damaged slabs with stone of similar characteristics.
Conservation and restoration research conducted prior to interventions, along with research conducted during structural reinforcement interventions, uncovered previously unknown and highly valuable historical layers of interior elements, primarily wall paintings and floor coverings. Especially noteworthy among the numerous findings is the medieval 15th-century wall painting in St. Anne’s Chapel in Gornja Plemenšćina. It will be thoroughly researched and presented as part of separate interior renovation programs. The wall painting in this chapel represents exceptional qualitative achievements in this region, and the rehabilitation procedures were adapted to its presence.
Several very interesting historical stone floor finds significantly influenced the quality of the final interior presentation. Particularly important are the Parish Church of the Holy Trinity in Donja Stubica, where a three-nave crypt was discovered along with the historical floor paving, and St. Magdalene’s Chapel in Lenišće, where a 17th-century stone floor was found beneath newer tiles. Major interventions were undertaken to present the floor paving from the period of construction of the baroque-classical parish church in Kraljevec na Sutli. Additionally, interventions on the historical stone floors are anticipated as part of the comprehensive renovation of the Suffering Jesus Chapel in Kostel and the Chapel of St. Cross in Sveti Križ near Tuhelj.
We should also highlight demanding structural interventions, such as the one carried out in the Parish Church of St. Helena in Zabok, which involved replacing the wooden dome from the early 20th century with a dome made of laminated wood and strengthened and stiffened with reinforced concrete tie beams, as well as the reconstruction of the wooden vault of the Chapel of Our Lady of Sorrows in Trgovišće. The rehabilitation of the church bell tower domes in Donja Stubica and Kraljevec na Sutli is also worth mentioning.
The final stage of the structural rehabilitation included plastering and painting the facade, which, considering the interventions carried out, involved the reconstruction of the layers that were best preserved before rehabilitation or were the only existing ones, with a few exceptions. In this regard, the choice of the composition and texture of the plaster, as well as the paint color shades, was based on the results of conservation and restoration research conducted ahead of interventions.
Ključne riječi
Krapina-Zagorje County, structural renovation; immovable cultural assets; conservation principles; wall paintings; historical pavings; facade renovation
Hrčak ID:
334851
URI
Datum izdavanja:
30.12.2024.
Posjeta: 641 *