This study focused on improving the understanding of the actual extent and spatial impacts of the Rupnik Line as one of the two fortification systems of the Rapallo Border. To this end, the available ...sources were checked and the understanding about the sectoral division of the Rapallo Border’s elements was derived therefrom. The field investigation done at a micro-location level revealed the real scope of the Rupnik Line fortification facilities. By identifying and recording the individual Rupnik fortification facilities in the Municipality of Žiri and by conducting interviews, we made an overview map showing the locations of these fortification structures. This basis, testifying to the actual condition and extent of the Rupnik Line fortification system at the level of the Municipality of Žiri, made it possible to develop further in-depth research questions regarding the spatial roles and values of this system.
The aim of this work was to investigate the possibility of the addition of phase-change material (PCM) to mortar mixtures and its effect on the material’s mechanical and thermal properties. This work ...included the preparation of mortar mixtures with two different water-to-cement (w/c) ratios as well as various PCM volume-fraction additions. The main objectives were to determine the effect of the w/c ratio as well as the PCM addition on the mechanical properties of the mortars after (3, 7, and 28) d of curing. Additionally, we examined the microstructure of the prepared mortar composites and evaluated their thermal behaviour. Microstructural analysis revealed the uniform distribution of PCM microcapsules throughout the mortar matrix, which contributes to the efficient storage and release of thermal energy. Thermal properties were analysed by repeated heating and cooling cycles of the mortar composites. The repeatability of the cyclic testing results showed a reversible melting and solidification phase change of the PCM and indicated the potential use of such composites as an energy-efficient building material. The study highlighted the potential incorporation of the PCM into mortar mixtures to improve their thermal properties while maintaining the mechanical integrity. The research findings provide valuable insight into the development of sustainable building materials with greater energy efficiency and structural reliability.
This paper investigates the origin of increased strength and water resistance of air lime mortar prepared by Triassic dolomite aggregate when exposed to humid or wet environments. The mortar ...specimens were exposed to various ageing conditions and analysed using petrographic and scanning electron microscopy equipped with X-ray microanalysis. Parallel to these analyses, X-ray powder diffraction and strength tests were performed on the specimens. It was revealed that reactions associated with the dedolomitisation process of the dolomite grains in the lime binder (hereafter alkali-carbonate reactions or ACRs) are the source of the improved strength and water resistance. An increasingly alkaline environment accelerated the ACRs substantially. Two parallel processes during the ACRs (dedolomitisation and CaCO3 dissolution/reprecipitation) were described in detail. Ageing temperature decisively influenced the kinetics of the dedolomitisation and dictated the path of the CaCO3 dissolution/reprecipitation process. After two years of ageing in a water-saturated environment at 60 °C, air lime mortar retained a great deal of its initial mechanical strength, and at 20 °C its strength was considerably increased. This somewhat unexpected observation was explained as being a result of microstructural changes and/or phase transitions.
•Combined lime-cement structural injection grouts were designed.•Time evolution of the grout setting process was monitored by proton NMR spectroscopy.•The grout setting process is significantly ...slowed down relative to the cement pastes.•Compressive strengths of the grouts are appropriate for historical buildings repair.•Swelling agent lowers the compressive strength of the grouts to an unacceptable level.
We present design and properties of combined air lime-white cement structural injection grouts containing 17.5% of air lime, 7.5% of cement and 75% of limestone filler, using white Portland cement. Time evolution of the grout setting process during hydration from early to late stages was monitored by NMR spectroscopy and compared to pure cement-paste control samples. The grout setting is significantly slowed down (by more than 10 days). The compressive strengths of the grouts were found in the range 1.5–2.5 MPa, making them efficient materials for the strengthening of historical masonry buildings in Slovenia.
The Rupnik military line was established in about 1935 in the Kingdom of Yugoslavia as a defence system against the Kingdom of Italy. It consists of more than 4000 reinforced concrete military ...bunkers positioned on the eastern part of the Rapallo border, varying in size and purpose, and was a top-secret project at the time. Different non-destructive and non-invasive techniques were used to characterise the selected bunkers and carefully conceived concrete samples to gain an insight into the concrete technology used to build these historic military infrastructures. The results of the non-destructive techniques were further compared to those of destructive techniques for a given property. It was established that very different concrete compositions were used to build the bunkers, and an extensive dispersion of the properties was confirmed for each composition. The average compressive strength of the Schmidt hammer for a given position is an acceptable estimate of the actual compressive strength of concrete without destructive intervention into a bunker. It also enables an estimation of the secant modulus of elasticity using the ModelCode2010 approach. Cylinders drilled from a bunker provided additional information about the concrete petrography, its physical and mechanical properties and the durability of reinforced concrete.
Some carbonate aggregates used in concrete are unstable in a high alkaline solution, which is present also in pore solution of cement binder. This paper investigates the process of dedolomitization ...of carbonate aggregate rocks and mortar bars. Selected aggregates, limestone and dolostone are of high purity without reactive silica involvement confirmed by the XRD and the XRF. For the process of dedolomitization the effect of various temperatures, solutions and time was examined. In this investigation, measurements of expansion, optical and scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction were used. Te results indicate that the process of dedolomitization occurred not only in the NaOH solution but also in the water on the mortar bar with virgin dolostone aggregate. Elevated temperature, 60°C, increased the rate of reaction. Furthermore, the rate of reaction significantly correlates with time, which has also been confirmed through the Rietveld analysis.
•The dedolomitization caused no expansion.•It occurs in the dolostone aggregate without reactive silica involvement.•It has taken place already with the presence of the cement binder.•A significant alteration occurred: formation of rims, new pores and phases.
The main clinical feature of dementia in Parkinson's disease is a dysexecutive syndrome. The neuropathology of PD dementia (PDD) is likely multifactorial and affects several neuronal populations. ...There is evidence that Parkinson's disease dementia is associated with a cholinergic deficit, supporting the therapeutic role of cholinesterase inhibitors, which are already first-line agents in the treatment of Alzheimer's disease. The paper includes short report on a pilot study with description of cognitive and imaging profiles in patients with mild to moderate stage of Parkinson disease dementia (PDD).
A random sample of 16 patients with clinical diagnostic criteria for probable PDD was included in the study. Patients were characterized with mild to moderate cognitive decline slightly depressive mood and moderate motor performance. Brain perfusion (99m)TcECD / SPECT and structural MRI with emphasis on evaluation of the degree of cortical atrophy and the medial temporal atrophy index was performed. All patients had detailed neuropsychological evaluation using a "cognitive process approach". Neuropsychological data were correlated voxel-wise with normalized brain perfusion images, creating whole-brain correlation maps.
Previously reported generalized cognitive impairment in PDD with predominant executive, visouspatial and attentional deficits was confirmed. Performance on specific cognitive measures was correlated with perfusion brain SPECT findings. It could be speculated that different pathological mechanisms underlie widespread significant brain perfusion decrements in temporal, parietal and frontal regions.
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