Historični materiali Rupnikove linije

Legan, Mojca (avtor), Marinšek, Marjan (mentor)

Namen magistrske naloge je bil raziskati historične materiale Rupnikove linije. Rupnikova linija je bila obrambna linija, ki je na naših tleh potekala med Jugoslavijo in Italijo, zgradili pa so jo pred drugo svetovno vojno. Linija je bila poimenovana po generalu Leonu Rupniku in je vključevala različne vrste obrambnih objektov, kot so betonski bunkerji in utrdbe, ki so jih uporabljali za skladiščenje orožja, zatočišča vojakov in zavetja za topništvo. Objekti so bili zaradi strateških razlogov običajno postavljeni na vrhu vzpetin, nekateri izmed njih pa so se ohranili vse do danes in so del naše kulturne dediščine. Za izvedbo eksperimentalnega dela sem si izbrala štiri različne objekte Rupnikove linije iz vrhov v okolici Žiri, s katerih sem iz konstrukcijskih elementov pridobila vzorce betona. Objekti Rupnikove linije so bili običajno zgrajeni iz dveh plasti betona (zunanja in notranja plast), vzorce pa sem pridobila iz obeh plasti. Z raziskovalnim delom sem ocenila stopnjo propada betona po njegovi 80-letni izpostavljenosti različnim vremenskim vplivom. Čeprav beton velja za trpežen material in je kot tak tudi najpogosteje uporabljen material v gradbenih konstrukcijah, je vseeno nagnjen k nekaterim strukturnim in faznim spremembam, ki lahko sčasoma posalbšajo fizikalne lastnosti betona. Na odvzetih vzorcih smo naredili optično mikroskopijo, elektronsko mikroskopijo in rentgensko praškovno difrakcijo. Iz dobljenih rezultatov sem ugotovila, da so bili betoni, uporabljeni pri gradnji Rupnikove linije, narejeni iz dolomitnega in kalcitnega agregata, ki sta bila pridobljena iz lokalnega okolja. Dolomitni agregat v betonu lahko sčasoma sproži reakcijo dedolomitizacije kot del širšega reakcijskega mehanizma – tako imenovane alkalno-karbonatne reakcije (ACR). Glede na pridobljene rezultate so bili dolomitni in kalcitni agregati betonov, uporabljenih v Rupnikovi liniji, presenetljivo malo prizadeti. Čeprav bi lahko pričakovali opazne strukturne in fazne spremembe v betonih, ki so bili 80 let izpostavljeni različnim vplivom okolja, se je izkazala precej nižja stopnja dedolomitizacije od pričakovane. Hkrati so bile strukturne spremembe, povezane z alkalno-karbonatno reakcijo, veliko bolj očitne v zunanjih betonskih plasteh v primerjavi z notranjimi plastmi.

• Jezik: Slovenski jezik
• Ključne besede: Rupnikova linija, historični materiali, alkalno karbonatna reakcija, dedolomitizacija
• Vrsta gradiva: Magistrsko delo/naloga
• Tipologija: 2.09 - Magistrsko delo
• Organizacija: FKKT - Fakulteta za kemijo in kemijsko tehnologijo
• Leto izida: 2023
• PID: 20.500.12556/RUL-144405
• COBISS.SI-ID: 142847491
• Datum objave v RUL: 20.02.2023

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Historical materials of Rupnik military fortification line

Izvleček

The aim of this Master thesis is research of historical materials used in Rupnik's line. Rupnik's line was a defensive line along the border between Jugoslavija and Italy, built on the Jugoslavian's side prior to the second world war and was named after general Leon Rupnik. The Rupnik's line included various types of defence structures like bunkers and forts, which were ment as weapons storages, shelters for soldiers or as artillery spots. Because of strategic position structures of the Rupnik's line were usually built on hilltops. Structures of the Rupnik's line nowadays belong to Slovenian cultural heritage. During the experimental work I chose four different structures of the Rupnik's line from the hilltops in the surrounding area of Žiri and took some concrete samples from each structure. Because buildings of the Rupnik's line were normally constructed with two concrete layers (outer and inner layer) the concrete samples were taken from both layers. Analytical work was focused on the evaluation of deterioration level of concrete after 80 years of its exposure to various weather conditions. Namely, although concrete is considered to be durable material and as such the most commonly used material in a construction, it is still prone to some structural and phase changes, which may in time worsen concrete physical properties. All collected samples were analysed by means of optical microscopy, scanning electron microscopy and x-ray diffraction. From the obtained results I concluded that concretes used in the Rupnik’s line were made with the use of dolomite or calcite aggregates obtained from local quarries. Dolomite as an aggregate in concretes may with time undergo dedolomitisation reaction as a part of larger reaction mechanism – the so called alcali-aggregate-reaction (ACR). However, according to the obtained results dolomite and calcite aggregates of the concretes used in the Rupnik's line were surprisingly only modestly affected. Even though one might expected significant structural and phase changes in concretes after their exposure to various weather conditions for 80 years, it turned out that the degree of dedolomitization was much lower than expected. Furthermore, structural changes associated with the ACR reaction mechanism were much more evident within outer concrete layers compared to inner layers.

• Ključne besede: Rupnik's line, Historical materials, Alkali Carbonate Reaction, Dedolomitisation