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Zpevnění bělavého degradovaného porézního vápence suspenzí nanočástic hydroxidu vápenatého v alkoholu
Slížková, Zuzana ; Frankeová, Dita
Vápence, které jsou poškozeny (degradovány) ve své povrchové vrstvě, a které mají vhodnou velikost pórů, tzn. že obsahují póry nebo praskliny s průměrem větším než jeden mikrometr, je možné zpevnit konsolidačním prostředkem, který obsahuje hydroxid vápenatý ve formě částic o velikosti stovek nanometrů. Suspenze (nebo též disperze, koloidní roztok, sol) nano-částic hydroxidu vápenatého v ethanolu může mít různou koncentraci a může se aplikovat do poškozeného vápence jednou nebo vícekrát v různém množství, podle koncentrace prostředku a podle vlastností kamene. Uvedený postup specifikuje materiálové zkoušky vápence prováděné před zásahem i možnosti minimalizace vzniku bělavého zákalu na povrchu ošetřeného kamene.
Plný tet: 0448865_2015_Slizkova_Frankeova_Zpevneni_belaveho_degradovaneho_porezniho_vapence_suspenzi_nanocastic_hydroxidu_vapenateho_v_alkoholu_PP_4 -  PDF
Plný text: content.csg - PDF
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Strengthening of weak historic renders with traditional and innovated consolidation treatment
Slížková, Zuzana ; Frankeová, Dita
The presented study was aimed to proof consolidation effects of different families of consolidants: inorganic agents (lime -based or silica-based solutions or sols), organic agents (silicic acid ester based consolidant) and their combination on the characteristics of weak mortars prepared in laboratory with different types of aggregates. Besides exploring consolidant-substrate interaction also the pozzolanic activity of the aggregate and the binder mortar component after reaction with lime (calcium hydroxide solution) was investigated in order to understand and describe the strengthening mechanism into consolidated mortars. As the study was based on experimental research, the production of mortar test specimens represented an important preliminary work. Different mortar components (various types of sand in terms of phase composition, clay, lime) and the same ratio of the aggregate and the binder were used in various mortar mixtures. Various mineralogical types of aggregate were used with the same grain size distribution (600 pieces of tubes of 40 mm in outer diameter, of the height of 40 mm and depth of 4 mm were prepared for testing the compressive strength, for the tension tests 550 thin plates of dimensions 40 mm x 100 mm x 4 mm were cast and 600 beams 20 x 20 x100mm were made for testing the flexural strength and other characteristics of reference and consolidated mortars). The sand used for mortar specimens was characterized by microscopic examination of thin section and also by X-ray diffraction, X-ray fluorescence spectroscopy and thermal analysis. The pozzolanic activity of the sands (reactivity with calcium hydroxide) was determined by means of the thermal analysis and supplemented by wet silicate analysis. The amount of the effective matter in the consolidant was the same for all agents per the square unit for all mortar types and specimen shape. One set of specimens was prepared as the reference set the second set was used for the evaluation.
Plný tet: 0443951_2015_Slizkova_Frankeova_Strengthening_of_weak_historic_renders_with_traditional_and_innovated_consolidation_treatment - PDF
Plný text: content.csg - PDF
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Zjištění materiálových vlastností vzorků přírodního kamene a umělého kamene z Mariánského sloupu na Hradčanském náměstí v Praze
Slížková, Zuzana ; Zeman, Antonín ; Petráňová, Veronika ; Viani, Alberto ; Pérez-Estébanez, Marta ; Frankeová, Dita ; Ševčík, Radek ; Mácová, Petra ; Janotová, Dana ; Hasníková, Hana ; Niedoba, Krzysztof ; Hauková, Petra
V rámci průzkumu před restaurátorským zásahem byly stanoveny materiálové charakteristiky přírodních i umělých kamenů, které jsou součástí Mariánského sloupu na Hradčanském náměstí v Praze. 15 vzorků bylo podrobeno rozsáhlým instrumentálním analýzám, jejichž výstupem je nejen chemicko-mineralogické složení vzorků, ale i stupeň jejich degradace včetně popisu porézního systému a úrovně zasolení.
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Characterisation of historic materials - the case of Tao-I-Kisra Palace (Iraq)
Slížková, Zuzana ; Pérez-Estébanez, Marta ; Viani, Alberto
The aim of this study is the characterization of bricks from the Taq-I-Kisra palace in southern Iraq (ancient Mesopotamian area). The palace is located in the plain of the Tigri river (see Fig. 1). The construction probably started around year 540 AD even if there is some uncertainty about its age. The arched hall on the facade is about 37 m high and is the largest vault ever constructed at the time (see Fig. 2). Originally conceived as an imperial palace, was later used as a mosque by the Arabs before being gradually abandoned. The historical constructions in this area are what remains of the capital of the empire. In accordance with geological data, in the area where the temple was built (and in general in the Mesopotamian area), the most available construction material was mud. Mud bricks were made mainly of clays. In ancient times there is evidence of mixes with sand, water, mud, and organic material, husks or straw.
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