Seismic demands for existing buildings though they all survived numerous earthquake events cannot be fulfilled as it concerns current code provisions. Thus rigorous strengthening measures should be introduced for the achievement of demanded seismic performance. Here the most important issues are how to solve the most vulnerable parts of the buildings while still preserving their architectural and historical values. For the palaces this is usually related to preservation of large halls with high floors considering the level of maintenance of the building and decay of built brickwork masonry. While for Kolizej Palace regardless the chosen methodology for the seismic assessment there were no efficient feasible strengthening solutions, for Kazina Palace different strengthening approaches were proposed corresponding to different desired seismic performances.
COBISS.SI-ID: 8320865
Circular economy is a relatively novel economic concept embraced by the European Union, which aims at replacing linear flow of raw materials characterised by taking, making and disposing to a circular flow where resources remain in the productive use as long as possible while waste, emissions of pollutants and energy consumption are minimised. Energy efficiency and life-cycle analysis of buildings provide useful tools to global and European efforts for a transition towards the circular economy. In this contribution, the impact of modern electromagnetic sensing methods on the implementation of the circular economy will be evaluated. An overview of electromagnetic sensing technologies for building and construction materials will be given with special emphasis on ground penetrating radar, THz spectroscopy and imaging methods. Special focus is given on applications for a selected GPR method, which has been tested using NI USRP 2620 with commercial antennas by Aaronia. The electromagnetic sensing techniques allow reduction of necessary building and construction materials throughout the life-cycle of the building, which represents a promising contribution to the circular economy.
COBISS.SI-ID: 31024679
The paper presents and discusses the process of alkali-carbonate reaction (ACR) in mortar, between dolostone aggregate grains and three different mineral binders: cement, hydrated lime, and combination of lime and tuff. The mortar bars were prepared from typical Slovenian late digenetic dolostone acting as aggregate. As binder, Portland cement CEM I, according to the European standard EN 197-1, was used for the first set of specimens, pure calcite lime putty was used for the second set of specimens, and combination of the lime putty and zeolite tuff was used for the third set of specimens. The specimens were exposed to accelerated conditions regarding the ACR, simulated by distilled water at 60 °C. The progress of ACR was studied using a petrographic microscope and scanning electron microscopy with X-ray microanalysis (SEM/EDS) after 3 and 6 months, and after 2 years. Compressive tests were also carried out parallel to the microscopic investigation. The results obtained at microstructural level show that ACR is progressive with time for all three binders studied. It reflects in the process of aggregate grains dedolomitization and the formation of secondary calcite in binder. However, extent of the microstructure change is not the same for all binders. Recrystallization that reflects in reaction rings, dedolomitization along preexisting cracks and so called paving structure, and in formation of secondary calcite, is faster for the cement binder. In case of specimens with the lime-tuff binder also a new reaction product rich in Mg and Si atoms was formed at the edge of the dedolomitized parts of the grains. The compressive strength of the mortar bars increased with time up to 2 years of the accelerated exposure for all studied binders, in great extent due to the observed change of the mortars microstructure.
COBISS.SI-ID: 8088673