Ústav technologie, mechanizace a řízení staveb

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Research Summary on Characterizing Impact of Environment on Adhesion of Sealed Joints in Façade Applications
(MDPI, 2020-10-29) Nečasová, Barbora; Liška, Pavel
The presented paper summarizes the main research findings on the impact of the environment concerning the durability and service life of building joint sealants. The focus is placed on sealed joints in façade applications, which can serve different purposes and can also be several meters long which often intensifies the stresses that the joint needs to withstand and therefore its service life can be significantly shortened. Different approaches, test sample geometries and high-performance sealants, were used in this context to determine the most critical aspects for the studied application sector. The research was divided into three phases where the joints were subjected to (I) artificial weathering in a laboratory environment, (II) real weathering in an external environment, and (III) weathering via a real application that was monitored for almost 4 years. The extensive research scope confirmed one commonly known presumption, that standardized artificial weathering/aging methods are not able, from a long-term perspective, to simulate the impact of a real environment. The most valuable results were obtained in the third phase of the research, where the monitoring of a real façade brought to light completely different conclusions. The joints exposed to the real environment were either completely deteriorated or showed signs of advanced aging.
Effective Use of Tower Cranes over Time in the Selected Construction Process
(MDPI, 2022-04-02) Motyčka, Vít; Gašparík, Jozef; Přibyl, Oto; Štěrba, Martin; Kurková, Dita; Kantová, Radka
The quality of preparations carried out before building work commences has a significant impact on the smooth running and overall financial costs of a construction project. The use of construction machinery, which is crucial with regard to the efficiency of the construction process, plays an important role. In building construction, the machines in question are mainly tower cranes. The paper presents a new method for assessing the utilisation of tower cranes over time during the construction of reinforced concrete monolithic structures. The method, which contributes to the efficient utilisation of such cranes, is based on a mathematical simulation model that predicts the work cycles of a tower crane during a work shift when work is being performed on individual construction sub-processes. Construction sub-processes are analysed in detail with regard to the service provided to them by a tower crane. Data can also be obtained from binding construction schedules and boundary conditions, which in every case are for a specific executed construction project. The simulation model of the work of tower cranes has been developed for use in software applications. The created application expands the possibilities of smart construction site design in a digital environment and can also be used directly from an internet browser.
Multi-Criteria Optimization of Mechanized Earth Processes and Its Impact on Economic and Environmental Sustainability
(MDPI, 2021-12-22) Gašparík, Jozef; Motyčka, Vít; Šťastný, Patrik; Szalayová, Sylvia
The optimization of mechanized construction processes has a very important impact on economic and environmental sustainability. Our analyses evaluate key factors that affect the quality, environment, and economics of mechanized earth processes. This paper also presents approaches in this area in Slovakia and abroad, and existing mathematical models for the optimal design of earthmoving machinery. The main goals of our paper are the proposal of a method of machine selection for excavation including a multi-criteria optimization method with software support and application and verification of this method in a model example. A total of nine scientific methods applied in our paper are analyzed. The key results of the research work in terms of the set goals are given in the Conclusion, where the key research results are summarized. The results of the research work presented in the paper have a direct impact on economic and environmental sustainability, which can be achieved already in the phase of construction preparation. Applications of information technologies in multi-criteria optimization of the selection of construction machines for earth processes enables their use in the BIM (building information modeling) model.
Analysis of construction sub-processes for the evaluation of the real performance of tower cranes
(IOP Publishing, 2021-08-30) Doubek, Rostislav; Kurková, Dita; Štěrba, Martin; Kantová, Radka
The productivity of work performed at construction sites is primarily dependent on the effective deployment and use of construction machinery. Nevertheless, manufacturers do not state the actual performance of their machinery because it is difficult to determine due to its dependence on the specific conditions present at each construction site. One of the most important machines used in the construction of buildings is the tower crane, which provides secondary transport of material onsite. In order to evaluate the effectiveness of the use of such machines using a deterministic or stochastic approach, a relatively extensive and exact set of data describing the activities of a given tower crane needs to be prepared. These data describe the real requirements of ongoing construction sub-processes with regard to the utilisation of tower cranes. This contribution concerns the analysis of key construction sub-processes during the building of monolithic reinforced concrete structures in connection with secondary transport at the construction site; in particular, it describes the preparation and processing of this data for the evaluation of real time requirements placed on tower cranes.
Advantages and disadvantages of modular construction, including environmental impacts
(IOP Publishing, 2021-09-03) Kurková, Dita
Similar to other fields, the construction industry tends to constantly evolve. There is an increasing demand for the construction of new buildings regarding the speed of the construction process, economy, and minimization of the negative effects on the environment, i.e. sustainability. These requirements can be met by using prefabrication for this construction. Modular construction represents one of the prefabrication technologies that is becoming increasingly popular worldwide. The topic of this article is the use of modular construction, even from the sustainability point of view. There is a basic overview of modular construction, its history in the construction field, an overview of the materials used, and the possibilities of its implementation. Furthermore, this article provides an overview of the advantages and disadvantages of modular construction. The advantages are listed in terms of quality, economy, time, and ecology as well as in terms of construction flexibility and work safety, both during production and assembly on the construction site. The disadvantages of modular construction discussed in this article are the complicated transportation of modules, demanding coordination of production and construction, the requirement for detailed construction planning, and the non-acceptance of this construction technology by the general, and sometimes professional public. This article also deals with the comparison of modular construction technology with conventional construction technologies. It points out the possibility of reusing materials from disassembled modular buildings. It also points out the ways to control and mitigate the impact of modular construction on the environment throughout the life cycle of modular building. Only after a thorough analysis of these aspects of modular construction, is it possible to explore other ways to further increase the efficiency of this technology in all directions and also to make even better use of its environmental impact minimization potential.

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