Advances in Science and Technology Vol. 109

Abstract: The assessment of the seismic safety level of masonry buildings is a current and important issue at the basis of the complex process of preservation of historical masonry buildings which constitute mostly the Italian and European towns. Nowadays, different approaches able to provide important information concerning the seismic safety level of masonry structures are available. Among these, fragility curves allow to have a prediction of potential damages during an earthquake of geographical areas characterized by similar construction typologies. The present paper concerns the derivation of fragility curves of masonry buildings, typical of Italian historical towns and mainly characterized by the possible occurrence of local out-of-plane collapse mechanisms. To this end, a real case is accounted in the study in order to consider specific parameters characterizing the constructions composing these territorial realities.

Abstract: Renovation processes of existing buildings, including historically protected ones, are most of the time focused on energy saving. Nonetheless these processes might affect the function of existing shallow foundations. This paper deals with the influence of soils moisture content onto the depth of freezing. The depth of freezing depends on the type of soil as well, not just the moisture content. The influence of water and soils composition are generally perceived to be substantial for depth of freezing. Sub-zero temperatures do significantly change the soils characteristics, which has an effect to the building structure. The purpose of the research done by the personnel of Brno University of Technology was to determine the effects of special measures against frost penetration of soil. These measures included the application of various materials and solutions over the terrain in winter to monitor frost depth of soil.

Abstract: The churches of the Broumov region are renowned for their unique baroque architecture, their distinct shapes, and sizes. They are an integral part of the Czech cultural heritage. If you analyze the churches, it becomes evident that both the local geological conditions and the municipal economic situation have played an important role in their current condition. Moreover, the local construction industry has been significantly affected by historical events. In this article we would like to present the effects of those factors on the current state of selected churches, namely on the bearing capacity of their walls. Besides being very interesting, it also plays a key role in the maintenance and the potential reconstruction of the churches.

Abstract: This paper deals with the possibilities of analysis of building materials in terms of chemical composition. Using the method of infrared spectroscopy, we can determine the organic compounds in coatings, adhesives, grout, and silicate materials. Building material characteristics have to be in accordance with the standards. However, due to external conditions, the material can degrade during its life. Observations and chemical analyses of the building materials must be performed to be able to do remediation and reconstruction of the historical building. Infrared spectroscopy was chosen as the best for qualitative analysis of organic admixtures in building materials.

Abstract: The facade of the old school is registered in the list of cultural monuments and located in the conservation zone of the urban monument reservation. Due to the construction of a new building, it was necessary to reinforce and structurally support (by means of an anchored reinforced concrete wall) the south wing of the old section of the school. No fissures were allowed to develop because they could damage the valuable art nouveau facades. Therefore, great emphasis was given to the technological and structural design of the reinforced concrete gunite wall. Precise geodetic measurements confirmed that the decline of the south wing of the school of the gunite wall was minimum, specifically 1,5 mm, after the completion. No cracks appeared. The building won first place in the “Building of the South Moravian Region” competition in 2018 in the category of public utilities in the Czech Republic – see www.gero.cz.

Abstract: The paper deals with the analysis of performed repairs and the current state of drainage and ventilation system of the Plasy convent and their evaluation. The Plasy historic water system is described in detail based on the results of a long-term field and structural survey. At the same time, unsuitable interventions, particular the application of chemical barrier, were analysed. Recommendations for further measures in the framework of the rehabilitation of the whole convent are made.

Abstract: A mayor problem in bridge engineering is the insufficient knowledge concerning the condition of prestressing reinforcement, especially in prefabricated bridge girders, which is largely related to the measure of grouting of cable duct. Therefore, this article deals with non-destructive methods that could verify the filling of cable duct with grout along their entire length, not just randomly in a few selected places. That is why it was decided to use modern non-destructive devices like GPR Live (8000), HILTI PS 1000 and Pundit 250 Array.

Abstract: In the course of repairs or upgrading measures, it is often necessary to provide floors with synthetic resin coatings. After the work has been carried out, bubbles may form. The article lists the various mechanisms that cause blistering (osmotic pressure, impurities in the aggregate of the screed or concrete, chemical reactions, e.g. alkali silica reaction). By aid of a case study, the procedure for determining the causes of blistering is given in more detail. The investigations have shown that the formation of bubbles was due to alkali-silica reactions of opal sandstone particles in the screed.

Abstract: The paper critically discusses the issue of reconstruction of a historic wooden structure carried out as part of the process of protection and interpretation of a place of special historical importance. The problem is presented on the example of historic log cabins located in the Tennessee state in the USA. These are the following architectural objects: the Cabin at the Meriwether Lewis Monument, the architectural complex in Wynnewood and The Historic Sam Davis Home and Plantation. The presented case studies contribute to the analysis of the horizon of authenticity both the reconstructed architectural structures and the historical sites in which they are located.