Sažetak: The post-fire mechanical properties of concrete represent an important set of parameters in the analysis of structural behavior after the occurrence of a fire. In this study, four mixtures of lightweight selfcompacted concrete with different fillers were tested. The tests were conducted by considering the ages of the specimens, which, in this study, were two, three, and five years old. The results show the residual mechanical properties of the specimens after they were heated to target temperatures of 300, 500, and 700 °C. After exposure to high temperature, the specimens were either left to gradually cool until they reached room temperature or rapidly cooled by water. A comparative analysis was conducted on the compressive strength, mass, and dynamic modulus of elasticity of the specimens using the codified residual values given in EN 1994 1- 2.

Ključne riječi: Self-compacting lightweight concrete, concrete fillers, fire, mechanical properties, age of concrete, cooling regime, residual properties

Sažetak: This article presents an experimental study on 81 specimens made from three different mixtures of clay and sand. To ensure uniform initial parameters, all specimens were prepared with an initial water content of 30%. Two series of unconsolidated undrained shear tests under different overconsolidation ratios were conducted on a direct shear apparatus: the first aims to determine the SHANSEP (Stress History and Normalized Soil Engineering Properties) parameters namely S and m, whereas the second is used for evaluating the preconsolidation pressure. This work has provided an opportunity to investigate the influence of sand content on SHANSEP parameters and moreover to study the reliability of the preconsolidation stress estimated by the SHANSEP procedure.

Ključne riječi: Undrained shear strength; Overconsolidation ration; Preconsolidation pressure; SHANSEP method.

Sažetak: This paper discusses the importance of studying and rethinking the history of the development of domestic industrial architecture. The chronology of the development of industrial architecture in Odessa against the background of the industrial history of Russia and Ukraine is considered. The main stages and time frames typical for Odessa are identified as pre-industrial (1791–1861), the stage of formation (1861–1917/20), industrial (1918/20–1985), and post-industrial (1986–present day). The paper presents a brief description of each stage along with the analysis of the current state of industrial architecture. In addition, the experience of the renovation of industrial facilities in Odessa is considered, and the main spectrum of new functions is revealed. Two types of renovation objects are identified: historically significant and typical. The renovation is considered as a method of stabilizing urban space.

Ključne riječi: Industrial architecture, renovation of industrial facilities, stabilization of urban space.

Sažetak: The smart hydro-energy hybrid system comprises a small hydroelectric power plant and a solar photovoltaic power plant as a part of energy input for the realization of smart cities. This paper introduces the critical period method (CPM), which can be used for system sizing. According to this method, if the total energy production is lower than the energy demand, a critical period should be defined based on the largest difference between demand and production. The period (day) in which that difference appears is called the critical period. If the energy demand during this period is satisfied, the demand on the remaining days of the year is also satisfied. Any possible breaks in energy production, caused by a reduction in the expected river-flow rates or insolation (in the case of cloudiness), will be reduced to a minimum. The use of such a hybrid system guarantees the production of electricity throughout the year. Such a hybrid system could facilitate the realization of a smart city and help achieve energy stability and security. Despite Croatia having great potential in terms of solar energy use and the large number of available watercourses, such a hybrid system has never been realized. In particular, CPM has not been applied previously anywhere in the world.

Ključne riječi: hybrid energy system; hydroelectric power plant; solar photovoltaic power plant; critical period method; smart city

Sažetak: The proper choice of insulation materials contributes to the long and reliable operation of the envelope of a whole building. This paper presents the results of moisture-content determination in materials used for internal thermal insulation under different hygrothermal conditions. In this study, surface and internal moisture contents were measured. Moisture sensors that enable constant monitoring of material moisture content but with different operational characteristics, were used in the analysis. The operating principle of the first method involves the conversion of the amount of infrared radiation reflected in an electric signal, and the second method involves the analysis of the electric impulse propagation velocity. The measurement results of both methods are used to determine the drying-out characteristics of components used in internal thermal insulation and the sorptive properties of the selected materials. The results of comparative studies are also presented for these proposed methods as well as the gravimetric method to determine the usability of the proposed methods in determining the dampness level. The overall measurement results helped determine the relationship between the internal and surface moisture contents and the time needed for the moisture content in different parts of the selected materials to equalize.

Ključne riječi: dampness; moisture content analyzer; time domain reflectometry; internal thermal insulation, nondestructive methods.

Sažetak: The Sergeevka resort is the largest climatic-balneal-mud resort in the south of Odessa region. This article presents an overview of the current state of the resort and an analysis of its transport-planning scheme. In addition, suggestions on the resort’s availability and improvement of its functioning are provided through reconstruction of the resort’s external (in particular with Odessa) and internal transport links. Based on the city-planning analysis of the existing access roads to the resort and within its territory, the study presents a concept of the organization of the transport scheme. Its basic arrangements will provide the opportunity for the development of the resort by contributing to the influx of vacationers and investments and creation of new workplaces.

Ključne riječi: health resort; urban planning; transport connections; Sergeevka; tourism strategy.

Sažetak: Currently, most communal utility management companies continually and automatically follow the changing trends in the drinking and wastewater quality (DWWQ) within their area of activity. Different control systems and applications are used for this purpose. Efficient monitoring of DWWQ should also include the analysis of water-quality parameters, such as the range of changes and trends. The method of Rescaled Adjusted Partial Sums (RAPS) is very suitable for the visualization and determination of the readily apparent features, which may be hidden from the common time-series plots of values. This paper presents different approaches for the tracking and analysis of the DWWQ parameters using a combination of the open-source spatial database, PostgreSQL, and the open-source GIS software. The proposed approach has not yet been used in the management of communal utilities. The main advantages of this modern system are the use of opensource programs and the high efficiency of water-quality monitoring with large datasets. However, the application of this system would require further training of employees in communal utility companies. The analysis results were all obtained for real locations.

Ključne riječi: drinking water; wastewater; quality; spatial database; GIS; RAPS