The article focuses on floor composite beams used in buildings. Within the scope of the conducted analytical and numerical studies, the authors compared the typical solution—namely, the T-shaped reinforced concrete beam—with various types of composite beams, the height of which could not exceed the predetermined usable depth of the beam cross-section. The analyses focused on traditional steel–concrete composite beams, which are widely used in civil engineering, as well as modern solutions, such as timber–timber and steel–timber composite beams. A new type of a steel–timber composite beam with a cold-formed girder made of two channels was presented in this study. Due to the flexibility of the connections, the timber–timber and steel–timber composite beams were examined under three different connection conditions: full composite action, partial composite action, and no composite action (friction only). Composite beams with timber slabs are consistent with the principles of sustainable construction, which makes their comparison with conventional solutions particularly relevant. The load-deflection curves and the bending resistance of the analysed elements were obtained using numerical simulations. In the numerical analyses, advanced material models were used. Composite beams with timber elements had lower stiffness than the steel–concrete composite beam. For this reason, meeting the serviceability limit state can be more challenging for such structures. Furthermore, the degree of shear connection in the composite beams with timber elements had a strong impact on their load-bearing capacity and end-slip. The steel–timber composite beam with a cold-formed girder had the most favourable resistance-to-mass ratio. The analytical results, and especially the numerical findings, provide a foundation for future experimental investigations.

This article discusses the design of reinforced concrete structures taking into account non-uniform soil conditions, as well as aspects of sustainable engineering. To achieve this, the soil-structure interaction was explicitly introduced into the numerical model of the investigated structure which meets serviceability and the ultimate limit state conditions defined in the relevant Eurocode standards. In the numerical experiment, non-uniform soil conditions, type of foundation (isolated footing, foundation plate), material parameters and size of the cross section of the elements (columns and beams) were analysed. The introduced heterogeneous soil profiles, determined by defining a parametrised, in terms of mechanical properties, spatial model of the layered soil, resulted in nonuniform settlement of the investigated structure. A global analysis of the three-dimensional reinforced concrete structure was carried out taking into account geometric nonlinearity with imperfections and material nonlinearity with creep. The displacement maps of the structure and the risk of collapse due to nonuniform settlement were established. Furthermore, an environmental so called life cycle assessment was performed for each variant analysed of the investigated structure. The innovative nature of the research is based on a joint approach to the problem of soil-structure interaction and the assessment of the carbon footprint of reinforced concrete buildings. This made it possible to determine how the varying soil conditions and different types of foundation affect the amount of material consumed and the carbon footprint associated with the production of reinforced concrete structures.

The article refers to the problems of adaptation of Collegium Chemicum facilities belonging to Adam Mickiewicz Uniwersity in Poznań to its storage needs. The subject building is situated in Grunwaldzka Street in Poznań. In the introduction part, the building and its structural solutions are described. The results of the materials research and the measurements of the used reinforcement have been presented. The structure diagnostic analyses were performed basing on measurements and research. The analysis allowed the determination of the limit loads. The results of the performed analysis of the current state turned out to be unsatisfactory, not only in terms of the planned storage load but also in terms of the current load state, as was shown by the construction analysis.

W artykule omówiono problemy konstrukcyjne związane z klawiszowaniem betonowych posadzek przemysłowych, czyli zjawiskiem podnoszenia i opadania płyt posadzkowych na stykach przerw dylatacyjnych i stykach rys przelotowych przechodzących przez całą grubość płyty. Opisano przyczyny projektowe, wykonawcze i technologiczne oraz eksploatacyjne występowania tego zjawiska. Nienaprawiane w odpowiednim momencie płyty prowadzą do uszkodzeń krawędzi płyt utrudniających dalszą eksploatację posadzki. W pracy przedstawiono stosowane w praktyce inżynierskiej rozwiązania konstrukcyjne i technologiczne zapobiegające niekorzystnemu zjawisku klawiszowania, realizowane na etapach projektowym i wykonawczym. Dalej opisano i przedstawiono skuteczne metody naprawcze płyt posadzkowych przywracające im pełną ich funkcjonalność i pierwotne funkcje użytkowe. Przedstawione rozwiązania projektowe i metody naprawcze odniesiono do wielkości obciążeń oraz do zakładanych parametrów geometryczno-wytrzymałościowych betonowych płyt posadzkowych i ich podbudowy.