Tom 116 (2019): Zeszyt 9 (September 2019)

A smart city is a city which, with the use of modern technologies, manages all areas of its functioning in order to optimise results of its development, create new values based on the cultural heritage and natural resources. However, it should be remembered that people create a city; therefore, the technology accompanying the idea of a smart city is only a tool that will be used by society in the process of the development. This paper aims to present the implementation of the objectives of intelligent urban space in the context of the concept of smart growth and the smart city. The author focuses on the analysis of selected approaches to shaping the intelligent city space related to activities within smart environment (blue and green infrastructure) and smart people and lifestyle (activity nodes and local centres). A smart’ city creates intelligent space.

This paper is a prolegomenon to the research on the history, architecture and state of preservation of the synagogues still surviving in the Podkarpacie region. After almost a millennium of Jewish presence in the area, despite wars and the Holocaust, 31 buildings or the ruins of former synagogues have remained until the present. It can be claimed that a Jewish cultural heritage of considerable value has survived in the Podkarpacie region to this day, and therefore requires protection and revalorisation. The paper presents the state of research in this area and an outline of the Jewish history of Podkarpacie, as well as a preliminary description of the preserved synagogues with regards to their origin, functional layout and state of preservation.

The article presents the cultural heritage of the mediaeval town of Lipnica Murowana, located in Lesser Poland in Bochnia County. This historic town can boast valuable architectonic and urban design buildings. These are the church of St. Leonard; the church of St. Andrew the Apostle; the church of St. Simon; the Starost’s House; the Ledóchowski Manor; the school building, relics of town housing and, primarily, the mediaeval urban layout with a market square. The article presents the history of the abovementioned historic buildings and spaces, and analyses their current protection and conservation guidelines.

Residential towers undeniably changed the reality that surrounds us. Vertical structures have influenced the landscape of cities by shaping new, previously unknown panoramas. Infinite peripheries were split and reassembled again in the vertical form. Is it possible to create a comfortable living space in a small area? Can residential towers fit into a fully fledged and well-functioning urban structure? Problematic aspects of this scenario are discussed on the basis of the most representative example in the world, which is Manhattan, located in New York City. Analysis of the urban structure of specific districts and examples of residential towers enables the presentation of the differences, advantages and disadvantages resulting from a specific given forms of architecture and urban planning.

This article presents the results of a housing market analysis for the city of Krakow. The market study was performed in May 2019 using the online survey method on a group of 104 persons who were currently searching for an apartment. Based on initial studies, the authors analysed the opinions of potential customers, identified the apartments enjoying the highest demand, described the preferences of potential buyers and the criteria that encourage buying real estate to the greatest extent. Based on the results of the study, it can be concluded that the perceived need for persons to have their own apartment is the most common reason for purchasing a property. The most desirable housing has between 40 and 60 square metres of usable floor area, is composed of three rooms, in addition to a kitchen and a bathroom, and has its own dedicated parking space.

Microstructure defines almost all material physical properties of a substance. Thus, its proper identification is essential for the assessment of material durability. Porous materials constitute the vast majority of those applied in civil engineering. The most important parameters describing a porous structure are the specific surface area, the shape and volume of pores and the pore size distribution. There are several methods which provide such results; however, each of them has some drawbacks. The main purpose of this paper is to compare results obtained by means of various methods commonly applied to the investigation of microstructure. These methods are mercury intrusion porosimetry (MIP), low temperature sorption of nitrogen and thermoporometry (TPM). The experimental research is conducted on aluminium oxide, which is characterised by unimodal pore size distribution and hardened cement paste prepared using portland cement (CEM I 42.5R with water-cement ratio equal to 0.5. The results obtained by the above--mentioned methods are thoroughly described and compared in this paper. Each of the presented approaches has some limitations; therefore, in order to receive a reliable description of porous microstructure, one has to apply at least two different experimental methods.

The article presents an analysis of the influence of the demolition process on the environmental impact of a reinforced concrete structure, based on recycled concrete aggregate (RCA). Two aggregate production scenarios, varied in terms of the scope, were adopted and the contribution of RCA to the total environmental impact as well as the influence of demolition on the environmental performance of RCA were determined. The NONROAD model was used in the research as a tool for calculating the emissions generated by the equipment used for the processing of construction debris. Environmental impacts were assessed on the basis of the Ecopoint value. Despite the large quantity of aggregate in the concrete mixture, it did not constitute a significant environmental impact. However, demolition was the dominant process in the production of recycled concrete aggregate and it is reasonable to consider this process in an environmental analysis.

The paper covers an analysis of guyed masts as per the second order theory. The influence of various types of mast shaft imperfections was analysed based on the example of a certain 200 m-high lattice guyed mast structure with 3 guy levels. The computations were performed taking into account the mast shaft with sway imperfections, imperfections associated with an offset of structure nodes and bow imperfections. As there are no guidelines concerning imperfections in the current European Standard EN 1993-3-1, the permissible assembly deviation values were taken as the reference point. Based on the obtained results of the analysis some final conclusions and comments have been formulated that may be useful in the design of mast structures.

The main goal of the research was to check the influence of different factors on the mechanical behaviour of the fluidised bed combustion (FBC) fly ash-based geopolymer. Tests have shown that the increasing the proportion of sodium silicate to sodium hydroxide causes a decrease of compressive strength and an increase of flexural strength. The addition of aggregate significantly increased flexural strength but decreases compressive strength. Samples cured at higher temperatures obtained higher strength. Finally, it was concluded that taking into account the mechanical behaviour, FBC fly ash-based geopolymer can be treated as an alternative building material; however, its strength is lower than a metakaolin-based geopolymer made of the same mixture composition.

Geometrical imperfections of compressed chords in truss girders generate loads on the transverse roof bracings which are connected to the truss girders. The real distribution of this load is contrary to the model presented in the EN 1993-1-1 standard. The influence of the shape of the truss girder with geometrical imperfections on the load of transverse roof bracing has been numerically analysed in this article. The most commonly used shapes of truss girders as well as selected geometrical parameters have been considered. The obtained research results were used to determine the load acting on roof purlins and bracing rods in a typical hall structure.