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Foundation of the buildings on the loessial soil is often associated only with difficulties resulting from the possibility of the collapse of the ground. For these reason, loess is too often unfairly disqualified as the construction subsoil in spite of its good strength and strain parameters. Thanks to continuous development of research and publications of the results, reliable data regarding loess are spread and, as a consequence, loess becomes more and more common soil used in the geotechnical
engineering.

Loess collapsibility has been studied since the middle of the 20th century, nevertheless, only the computer techniques and specialist laboratory and microstructural tests, that have been developed from the end of last century, helped us to find an answer to the important questions regarding the occurrence of this phenomenon. Detailed mechanisms that cause sudden loess volumetric reduction due to humidity and load, and the elements that affects the collapsibility are still studied. Furthermore, varied technics are researched, including in-situ tests, which allow estimating the risk of collapse, as well as the methods of its elimination.

The aim of this paper is to systematize the directions of current studies of European loess collapsibility and to indicate their most significant results. The review was made on the basis of the scientific publications published in the Polish and international journals as well as the Journal Citation Reports (JCR) Web of Science database.

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This article investigates the role of light in the perception of contemporary architecture. Light is an essential element that creates and reveals the beauty of architecture, emphasizes its aesthetic values, and allows us to feel the unlimited space "with one’s whole self". Since time immemorial, light in combination with colour has played an important role at the design stage and later in its reception. Nowadays, technological and civilization progress has contributed to the increase in the role of light and color, enabling their application already at the moment of design. Increasing expectations towards architects have led to an intensification of the phenomenon, which is increasingly expressed in projects filled with light and colour.

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The paper assesses thermomodernisation measures aimed at improving energy efficiency of dwelling houses in a city quarter in Upper Silesia, Poland. The area was encompassed by the city council’s program of emission restriction that promoted energy saving activities. The assessment was carried out by means of thermographic examination. It confirmed the fact that the thermomodernisation measures taken so far provided considerable improvement, but did not solved all issues. Further works should be undertaken on the basis of thorough examination of the current condition of the buildings.

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The study of urban development and regeneration of residential areas in the cities are mainly focused on the separate infrastructural systems and less how networks of infrastructural systems and their elements, as nodal places, interact with the existing living environment and its urban tissue. The central goal of the paper is to examine contemporary residential areas of low liveability with nodal places of logistics and services infrastructural networks, with an eye on existing urban policies and application of transdisciplinary concept of stigmergy in contemporary urban environment. Research objectives: (a) conceptualisation of stigmergic process in urban planning; (b) overview of socialist and post-socialist urban policies for residential areas; (c) stigmergic behaviour in the development of nodal places in residential areas. Methodology: Use of Earth Time Observation Systems for identification of urban changes of nodal places under the stigmergic behaviour in the case study residential area in post-socialist city in Ukraine; contextualization of the case study with the categories: Ideology, Institutional level, Politics, Economics, Mobile Infrastructures. Discussion and conclusion: (a) as concept, stigmergic behaviours are efficient, but work as a self-organization form; (b) urban policies should, under the stigmergic behaviours, contextualize changes, continue or prevent the process.

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The paper deals with economical aspects concerning the quality control of concrete. About 70% of total concrete production is connected with the structural concrete, the subject of quality control and/or conformity. When checking the conformity criteria for a compressive strength of concrete for a small number of samples, qualification errors do not affect the formation of costs associated with losses on external deficiencies. In order to avoid costs related to qualification errors and losses on external deficiencies, the number of samples should be set larger than the minimum (included in contract’s clauses). Furthermore, the designer recommendations should be indicated in the specification. In the paper the costs concerning quality control for concrete have been analyzed.

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The paper examines the application of the tensor calculus to the classic problem of the pure torsion of prismatic rods. The introduction contains a short description of the reference frames, base vectors, contravariant and covariant vector coordinates when applying the Einstein summation convention. Torsion formulas were derived according to Coulomb’s and Saint-Venant’s theories, while, as a link between the theories, so-called Navier’s error was discussed. Groups of the elasticity theory equations were used.

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Ever since the field of Fire Safety Engineering first came into existence, small-scale (model scale) fire tests were the source of much valuable information about the phenomena occurring during combustion. Over the years, several computational methods to determine the criteria for the similarity of fires on both a real and small geometric scale have been developed. The purpose of this article is to present a method of performing fire tests on a model scale using the Froude number. The basics of scaling, similarity conditions that must be preserved, ways of describing fire phenomena, as well as methods of calculating fire parameters from the real and model scale have been discussed. An example of physical tests with the use of reduced research models is also presented. What is particularly emphasized is how important these types of experiments are and what responsibility rests with the people who carry them ouvol. The motivation to conduct research is the safety of people who reside in buildings with fire protection based on model scale test.

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This paper presents an analysis of the fire resistance of a steel joint subject-ed to tension. The authors of this article used prescriptive rules and simple calculation models to present an impact of the value of the load on the fire resistance of the connection. Designers often evaluate the critical temperature and fire resistance time of steel elements. However, they neglect the evaluation of the above-mentioned values for steel connections. In this article a simple engineering method was used to calculate the fire resistance of the joint.