Czech Technical University Research Articles

House FIRSTLIFE in student contest and in Living Lab

Abstract The paper comments on selected measurements and observations related to the FIRSTLIFE house demonstration unit, which was prepared by the team of the Czech Technical University for the international competition Solar Decathlon Europe 21/22 with its final at the Solar Campus in Wuppertal, Germany. The paper comments on the measurement results obtained during the competition in the field of building physics (thermal and moisture comfort, measurement of air permeability, measurement of sound insulation of the perimeter wall and dynamic co-heating test). The second part of the paper describes selected follow-up activities. For the purposes of the Living Lab, eight of the competition houses remained on the Solar Campus for at least another 3 years. This allowed long-term monitoring and targeted experiments to be carried out and some of the earlier measurements to be repeated under different climatic boundary conditions. For this phase, additional sensors were added in the Czech house, such as a meteorological station and temperature and heat flow sensors in the perimeter wall. Part of the data comes directly from the building management system. The paper comments on first results from Living Lab period.

DEVELOPMENT OF A ROBOTIC FABRICATION SYSTEM FOR CEMENTITIOUS MATERIALS

Our team at Klokner Institute under Czech Technical University in Prague is working in a joint effort with Technical University of Liberec and Klokner on a comprehensive 3D printing system for cementitious materials, including specially optimized robotic arm. The goal of this system is to decrease the environmental impact of construction industry by reducing the volume of materials and time required, as well as reducing need for human labor. 3D printing also makes possible to build complex functional shapes, that would be too complicated or prohibitively expensive to manufacture using standard industry methods. Combining expertise of these two institutions lead to development of a robust system, that seamlessly integrates in-house developed mechanics and print material. One of key areas of our research is also testing mechanical properties of printed parts which is essential to safely integrate this construction method in real-world use in the future.

Problems with reinforced concrete industrial floors with regard to subsoil swelling

Most of the problems associated with open cracks in reinforced concrete industrial floors do not arise from technological indiscipline in the execution or exceeding the permitted floor load, but from the geotechnical profile beneath the floor. In the presence of swelling soil in the subsoil, the floors can then be shifted upwards by centimeters and create open cracks. This article describes regression relationships for the prediction of swelling pressure and deformation of reinforced concrete industrial floors based on indirect measurements. These relationships were obtained by evaluating a large database of measurements carried out by the company GeoTec-GS and the Czech Technical University in Prague using neural networks, multiple correlation, regression analysis, and sensitivity analysis. The article also presents the actual classification of the risk of surface damage of reinforced concrete floors due to swelling of the subsoil and an example of its application is given.

European Journal of Geography (Year 2023): Reviewer Appreciation & Publication Recap

European Journal of Geography (Year 2023): Reviewer Appreciation & Publication Recap

Students training on virtual medical linear accelerator

At the Czech Technical University in Prague, we have installed virtual software environment simulating a radiotherapy treatment room with a medical linear accelerator (software VERT and VERT Physics by Vertual Ltd., United Kingdom). It is possible to simulate patient treatment and physics QA (quality assurance) measurements in virtual reality. This is beneficial for our students and teachers because there is no radiation present while doing the exercises and it is accessible at any time, unlike medical linear accelerators at hospitals. For our department, we have chosen the TrueBeam model by Varian Medical Systems, USA. The linear accelerator can be operated by the user in the same way as at the hospital, including the hardware pendant. There is a selection of patient treatment plans, CT images and RT structures, all of which can be visualised inside the treatment room, also during beam on, simulating the situation inside the patient while irradiating the tumour. Any DICOM files, even from another manufacturer’s linac (linear accelerator) or treatment planning system, can be imported into VERT. Apart from this, there is also an imaging interface and cone-beam CT interface showing options for patient setup. Another part of the software is a physics module with various phantoms and detectors for dosimetry as well as geometry tests. For example, a large water tank can be used for relative dosimetry of photon beams (percent depth doses and profiles), a smaller water phantom can be used for reference dosimetry or chamber cross calibration according to the TRS 398 (1) or IPEM (2) protocol. The results of measurements are based on look-up tables coming from real beam data, so dependence on the depth of measurement, field size, temperature and pressure and other parameters can be demonstrated. Moreover, it is possible to introduce many types of errors into the linac, such as jaw position, laser, or collimator miscalibration, and show how these errors propagate to patient irradiation and how they can be detected by QA tools. This paper is a short report on how this system has been used at our university and how it might be used in modern learning, pointing out its advantages and drawbacks. At the 16th Workshop on European Collaboration in Higher Education on Radiological and Nuclear Engineering and Radiation Protection (CHERNE) it was proposed that this virtual system could be used for an international student training course on medical physics in radiotherapy within the CHERNE network. This course might contain theoretical lectures with demonstrations on the virtual linac, practical exercises on the virtual linac and visits to hospitals (a photon radiotherapy centre, the Thomayer University Hospital in particular, and a proton therapy centre).

Investigation of Buddhist and Bon votive statues at the Very low power reactor VR-1

The nuclear analytical techniques are excellent tools for the investigation in various research disciplines, i.e. cultural heritage preservation, archaeology or anthropology. Most of these radioanalytical techniques require sufficient sources of radiation. So far, neutron imaging has mostly been used at high-power neutron sources, i.e. high-power research reactors. On the other hand, small nuclear research reactors can provide more options for investigations in multidisciplinary research. Since the development of the NIFFLER neutron imaging facility in 2020, neutron imaging has been one of the nuclear analytical methods used at the very low-power research reactor VR-1 of the Czech Technical University in Prague. This paper deals with the investigation of the internal structures of Buddhist and Bon votive statues from Central Asia at the Training reactor VR-1. The experimental investigation was conducted to explore the possibilities of using neutron imaging for cultural heritage research at very low-power research reactors such as the VR-1 reactor. The results of these unique experiments clearly showed the potential of the VR-1 reactor or possibly other very low-power research reactors in neutron imaging for multidisciplinary research, which can provide important data for anthropologists, archaeologists or experts in cultural heritage preservation.

Preface

This volume contains contributions to the XII. International Symposium on Quantum Theory and Symmetries (QTS12) was at Czech Technical University in Prague, Czech Republic, from Monday July 24 until Friday July 28, 2023.The Symposium series “Quantum Theory and Symmetries” (QTS) is a biannual meeting intended for physicists and mathematicians who are either applying symmetries to some physical model, or are studying mathematical objects that are relevant for physical applications.The first Symposium of this series was held in Goslar (Germany) in 1999, QTS-1, then it was held in Cracow (2001) QTS-2, Cincinnati (2003) QTS-3, Varna (2005) QTS-4, Valladolid (2007) QTS-5, Lexington (2009) QTS-6, Prague (2011) QTS-7, Mexico-city (2013) QTS-8, Yerevan (2015) QTS-9, Varna (2017) QTS-10, Montreal (2019) QTS-11.The Symposium QTS-12 was first planned to be in Moscow at the Moscow Institute of Physics and Technology in 2021, but was postponed by one year due to Covid-19, then it was postponed to 2023, July 24-28, and was held in Prague at the Czech Technical University (Department of Mathematics, Faculty of Nuclear Sciences and Physical Engineering, CTU in Prague) QTS-12.The Symposium QTS-13 is planned for the 2nd half of July 2025 to be held in Yerevan, Armenia.The volume is organised as follows: it starts with notes in memory of H. D. Doebner. Then the invited talks at the plenary sessions and the public lecture are published followed by contributions in the parallel and poster sessions in alphabetical order.List of Editors, Advisory committee are available in this Pdf.

Resonance cavity as an education tool in PlasmaLab@CTU

PlasmaLab@CTU is a laboratory at the Czech Technical University in Prague dedicated to train new fusion physicists and engineers in plasma physics and technology with focus on the plasma diagnostics. The resonance cavity is one of the devices which train students in handling microwaves together with vacuum and plasma physics. The contribution will present the design of the resonance cavity, and measurements of the density as the function of the pressure in different gases. It will also present this experiment as an educational tool for the fusion community.The resonance cavity is a metal cylinder placed inside a glass container. It can be evacuated via holes in the top lid. Plasma is generated between an electrode inserted inside and the cylinder itself by RF source with the frequency of 13.5 MHz, and the power of roughly 70 W. Two antennas are placed inside the resonator in the bottom lid to launch and measure the resonant modes in the cavity. Plasma density can be estimated from the shift of the resonance peaks with/without plasma.The experiment can operate with five gases. It can be remotely controlled via its own interface through the internet. The remote control is an important feature of the PlasmaLab@CTU. It aims in continuing in the tradition of educational events already established by the GOLEM tokamak.

The measurement of the influence of the adhesion loss on the dynamic load of the drive reaction rod on the roller rig

The dynamic behaviour and dynamic phenomena in traction drives of railway vehicle has been studied for decades. Generally, in these days the motivation for this research is to look for answers related with service problems, which has been risen, e.g. an overloading of mechanical components as wheelsets or an intention to improve control systems of traction drives of railway vehicles. This problematic has also motivated the research at the Faculty of Mechanical Engineering at the Czech Technical University (CTU) in Prague. Nowadays it is also usual, that the main research tool has been a simulation based on a mathematical model of a railway vehicle or its specific components, as testing on real vehicles is very demanding regarding costs. However, there is an alternative – a roller rig. At the CTU in Prague there has been modernized the second roller rig for purposes of measurement regarding the torsion dynamics research, to support PhD students for their theses and possibly to extend the education for students oriented on the railway vehicle’s design. This contribution brings results of measurements just from the problematics of torsion oscillations and dynamics. Specifically, further presented measurements are on the loss of the adhesion in the contact of the wheelset and rollers, as the substitution for the railway, its impact on the reaction rod overloading and study of the axle load influence on the transition phenomena.

Weld size and resistance in rectangular hollow section T-joints

When chord face failure occurs, one of the factors, which influence the resistance of the square hollow sections joint is the brace-to-chord width ratio of the joint. This includes the size of the weld connecting the two members. The influence of weld type and weld size on the behaviour of rectangular and square hollow section joints was studied at the Czech Technical University in Prague.This paper describes an experimental and numerical investigation of square hollow section joints. The welded T-joints were loaded by axial compression. Three different types of welds were investigated - butt welds, fillet welds and a combination of these types. Experimental results for the T-joint together with material characteristics are provided. The paper presents a validation of the numerical model to experimental data. The research-oriented model with shell elements, prepared in RFEM finite element software, represents well the behaviour of square and rectangular hollow section joints. A parametric study with a broader range of sections was performed using the design-oriented shell elements model. Based on the results of the experimental and numerical investigations a modification of the analytical equations used in current prEN1993-1-8:2021 is proposed.

Application of the Source-Jerk method using a neutron generator in a subcritical reactor

This paper describes the application of the Source-Jerk method using a neutron generator in the VR-1 reactor. The experiments were carried out on a shutdown reactor with subcriticality greater than -10 βeff. A D-D neutron generator located in the radial channel of the VR-1 reactor was used as an external neutron source for the Source-Jerk method. The obtained results were discussed and compared with a conventional Source-Jerk method used at the VR-1 reactor and with the values calculated by the Serpent 2 code. The presented experimental works and their results will allow to extend the methods of reactivity measurements on the VR-1 reactor. They will also help to optimise reactivity measurements on the new subcritical reactor VR-2, which is currently being commissioned at the Czech Technical University in Prague.

Reconstruction with a double-constrained implant design after complex shoulder extra-articular resection

BackgroundApproximately, one-third of patients with tumors of proximal humerus will require an extra-articular resection to achieve oncologic margins. This procedure yields poor functional outcomes with a considerable rate of revisions. Unconstrained implants are prone to instability hindering also function of the elbow and hand, whereas constrained shoulder reconstructions suffer from early aseptic loosening of the glenoid component due to bone overload. The purpose of this study was to develop a constrained implant suitable for extra-articular resection with loss of function in deltoid and rotator cuff, which would provide both stability and passive motion, whilst also decreasing the risk of aseptic loosening of the glenoid component.MethodsIn cooperation with Czech Technical University in Prague, we devised an implant consisting of two constrained joints in series connected by a dumbbell piece. The biomechanical analysis showed a reduction of load transfer to the glenoid component with a torque of 8.6 Nm capable of generating an 865-N pulling force on bone screw to just 0.07 Nm, hence shielding the glenoid component from undesired forces and decreasing the risk of aseptic loosening. Three patients with extra-articular resection with a total loss of function of both rotator cuff and deltoid muscle received this type of reconstruction. The average follow-up was 16 months.ResultsThe surgical technique is straightforward. The surgery took 175 min on average with average blood loss of 516 ml. There were no surgical- or implant-related complications. All three patients were pain-free and had a stable shoulder joint after the reconstruction. All had fully functional elbow, wrist, and hand joints. The average Musculoskeletal Tumor Society (MSTS) score was 21/30 (70%). All patients were pleased with the results.ConclusionThe presented innovative implant design has demonstrated to be a promising alternative for reconstruction in these challenging cases.

Models to Analyze Risk in Time and Cost Estimation of Tunneling Projects

Time and cost estimation of tunneling projects is usually performed in a deterministic manner. However, because the deterministic approach is not capable of dealing with uncertainty, probabilistic methods have been developed over the years to better account for this problem. Three models of this type are the Decision Aids for Tunneling (DAT) and two models developed at KTH Royal Institute of Technology and the Czech Technical University in Prague. To conduct a probabilistic time and cost estimation, it is important to understand and account for not only the uncertain factors that affect the project time and cost but also the involved parties’ different interests and contractual responsibilities. This paper develops a risk model for the specific purpose of time and cost estimation of tunneling projects. In light of this model, the practical application of the three probabilistic models is discussed from a risk-aware decision-maker’s perspective. The acquired insights can be helpful in increasing the experts’ risk-awareness in modeling time and cost of tunneling projects.

Online training and education from the VR-1 reactor—Lessons learned

Hands-on education and training is a key part of fixing and developing technology knowledge and is an inherent part of many engineering and scientific curricula. However, access to large complex training facilities, such as nuclear reactor, could be limited by various factors, such as unavailability of those facilities in the region, high traveling costs or harmonization of the schedules of hands-on E&T with theoretical lectures and with the operational schedule of the facility. To handle the issue, several success stories have been reached with the introduction of the Internet Reactor Labs (IRL). The Internet Reactor Labs can strongly contribute to accessibility of training at research reactors and can contribute to improvements in their utilization. The paper describes the development of the Internet Reactor Lab at the VR-1 reactor of the Czech Technical University in Prague. Contrary to single-purpose IRLs, it presents various modalities of online teaching and training in experimental reactor physics and reactor operation in general as well as outreach activities that have been developed in recent years.

Fast on-line dissolution of KCl aerosol particulates for liquid-phase chemistry with homologues of superheavy elements

Research orientated towards the liquid-phase chemistry of homologues of the SuperHeavy Elements (SHEs) has been carried out at the Department of Nuclear Chemistry, Czech Technical University (CTU) in Prague in the recent couple of years. As a part of this research, a versatile apparatus for on-line aqueous chemistry of SHEs and their homologues is under development. One of the key features of the apparatus is the direct dissolution of radionuclide-carrying aerosols from a gas phase into an aqueous phase. In this work we describe coupling of the Particle-Into-Liquid Sampler (PILS), originally developed as a sampling system for the determination of aerosol composition by ion chromatography, with the Gas-Jet Transport (GJT) system that delivers cyclotron-produced Nuclear Reaction Products (NRPs) from a Recoil-Transfer Chamber (RTC) to the laboratory. The NRPs delivered to the laboratory are in the form of species adsorbed onto the surface of solid KCl aerosol particulates (adsorption takes place in the RTC) and such a mixed phase must be promptly and effectively transferred into a stream of an aqueous phase, in order to account for extreme instability and scarcity of a superheavy element. Compared to systems that have been used for this purpose in the past, the experimental layout of PILS-GJT turned out to be very promising, as its pilot test provided sufficient PILS efficiencies (40%–58%) and a very high gas-liquid (V/V) mixing ratio (up to 5800). These parameters also make the system suitable for future coupling with various microfluidic chemistry systems.

Investigation of concentric-zonal color effects in polyphase ceramic samples by x-ray fluorescence analysis.

The purpose of this study is to investigate and analyze new concentric-zonal color effects in polyphase ceramic samples, particularly in a ceramic sample obtained from coal ash in the Ekibastuz coal basin. The study aims to explore the nature and characteristics of these color bands through x-ray fluorescence analysis, and provide a qualitative and quantitative analysis of the obtained x-ray fluorescence spectra. This paper presents the results of the study of new volume-surface concentric-zonal color effects in polyphase ceramic samples. Concentric-zonal color bands on the cross-sectional surface of a ceramic cylindrical sample were investigated by using x-ray fluorescence analysis. The experimental work was carried out at the laboratory of the Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague. A comparative qualitative and quantitative analysis of the obtained x-ray fluorescence spectra was carried out.

CHISA 2022 – 26th Worldwide Meeting of Chemical Engineers

You have just started reading a Special Issue of Chemical Engineering & Technology which consists of contributions (both oral and poster) presented at 26th International Congress of Chemical and Process Engineering – CHISA 2022. It was the first Prague's face-to-face meeting of chemical engineers after restrictions connected with Covid-19 pandemic and it was organized with great enthusiasm because everyone was looking forward to personal interactions. It was held during August 21–25 in Prague at the Faculty of Civil Engineering, Czech Technical University in Prague. Chemical Engineering is a multidisciplinary scientific field that covers topics like reaction engineering and catalysis, computer process design, separation processes, and multiphase reactor systems. The format of the CHISA Congress has been changed from its previous versions. The main topics covered a wide range of disciplines starting at Ethics in Chemical Engineering through Global Thoughts, Matter in Motion to Green Issues and Energy and this change in format has lead towards more intense interaction between chemical engineers of all professional levels – students, academics, scientists, and industrial experts. The participants were invited to attend many interesting contributions dealing with the influence of chemical industry on the environment and reducing its impacts, mathematical modeling of the most important industrial processes and development towards their improvement, new processes leading to production of green energy, synthesis of new materials and catalysts together with economic evaluation of processes and many more. Due to the multidisciplinary scope of the conference, each participant was able to attend a substantial number of contributions of his own interest. The conference is very well known for its high scientific quality and this year was not different. The CHISA congress is also famous for its rich social program and is considered a place “where science meets culture”. The cultural program covers, e.g., a night with classic music, a student beer party, and a congress dinner. This ultimate mix of heterogeneous activities contributes to a better interconnection between students, academics, and industrial experts which always leads towards more intense cooperation. I would like to express my deepest appreciation to all participants of the conference and also to those who were willing to contribute a paper to this Special Issue. I would also like to apologize to others who could not make it to its final publication. The level of the contributions was of high quality and the role of a Guest Editor is always very difficult. I would also like to thank Dr. Barbara Boeck, Editor in Chief of Chemical Engineering & Technology, for giving me the opportunity to be the Guest Editor for the first time. I hope you enjoy reading this issue and I am looking forward to seeing you at the next CHISA congress in 2024. Dr. Pavel Krystyník Faculty of Environment, Jan Evangelista Purkyne University in Usti nad Labem Institute of Hydrodynamics of the Czech Academy of Sciences Pavel Krystyník

A smeared crack formulation for simulating fracture of fibre-reinforced concrete by means of a trilinear softening diagram

This study presents a smeared crack model for reproducing the fracture behaviour of FRC that is based on an embedded crack formulation used lately with this material. In both cases, a trilinear softening diagram allows reproducing the post-peak behaviour correctly. The model proposed here differs from the one on which it is inspired, since it is a smeared crack model based on the crack band concept where the material damage is isotropic and controlled by a damage factor ranging from 0 to 1, while the original model is an embedded crack model that allows fracture in three directions per element. This new formulation overcomes some limitations of the embedded crack model, that could only be used with triangular elements with an only integration point, since it can be used with triangular and quadrilateral elements with any number of integration points. Unlike previous models, developed for commercial codes, this model is developed in OOFEM, a free finite element code developed at the Czech Technical University in Prague (Czech Republic) and Chalmers University of Technology (Sweden), thus providing the general public with an advanced tool that allows reproducing fracture in structural elements made with fibre-reinforced concrete elements. This work shows that the proposed formulation provides similar results to those obtained with the model on which it is inspired under different situations: mode I fracture, size effect analysis and, finally, modes I and II mixed fracture.

IARD 2022 The 13th Biennial Conference on Classical and Quantum Relativistic Dynamics of Particles and Fields

Preface The International Association for Relativistic Dynamics was organized in February 1998 in Houston, Texas, with John R. Fanchi as president. Although the subject of relativistic dynamics has been explored, from both classical and quantum mechanical points of view, since the work of Einstein and Dirac, its most striking development has been in the framework of quantum field theory. The very accurate calculations of spectral and scattering properties, for example, of the anomalous magnetic moment of the electron and the Lamb shift in quantum electrodynamics, and many qualitative features of the strong and electroweak interactions, demonstrate the very great power of description achieved in this framework. Yet, many fundamental questions remain to be clarified, such as the structure of classical relativistic dynamical theories on the level of Hamilton and Lagrange in Minkowski space as well as on the curved manifolds of general relativity. There, moreover, remain the important questions of the covariant classical description of systems at high energy for which particle production effects are not large, such as discussed in Synge’s book, The Relativistic Gas, and in Balescu’s book on relativistic statistical mechanics, and the development of a consistent single and many body relativistic quantum theory. In recent years, highly accurate telescopes and advanced facilities for computation have brought a high level of interest in cosmological problems, such as the structure of galaxies (dark matter) and the apparently anomalous expansion of the universe (dark energy). Some of the papers reported here deal with these problems, as well as other fundamental related issues.It was for this purpose, to bring together researchers from a wide variety of fields, such as particle physics, astrophysics, cosmology, foundations of relativity theory, and mathematical physics, with a common interest in relativistic dynamics, to investigate fundamental questions of this type, that this Association was founded. The second meeting took place in 2000 at Bar Ilan University in Israel, the third, in 2002, at Howard University in Washington, D.C., and the fourth, in 2004, in Saas Fee, Switzerland. Subsequent meeting took place in 2006 at the University of Connecticut Storrs, in 2008 at Aristotle University of Thessalonica, in 2010 at National Dong Hwa University, Hualien, Taiwan, in 2012 at the Galileo Galilei Institute for Theoretical Physics (GGI) in Florence, in 2014 as the University of Connecticut Storrs, Connecticut, in 2016 at Jožef Stefan Institute in Ljubljana, Slovenia, and in 2018 in Mérida, Yucatán, Mexico, under the sponsorship of the Instituto Politécnic Nacional. The 2020 meeting, planned for Czech Technical University in Prague, was successfully held online at the height of the Covid-19 pandemic, and the physical meeting in Prague was delayed to 2022.The 2022 meeting forms the basis for the Proceedings that are recorded in this issue of the Journal of Physics: Conference Series. Along with the work of some of the founding and newer but already much engaged members of the Association, we were fortunate to have lecturers from application areas that provided strong challenges for further developments in quantum field theory, cosmological problems, and in the dynamics of systems subject to accelerations and the effects of general relativity. Topics treated in this issue include studies in general relativity and astrophysics, relativistic dynamics and electrodynamics, quantum theory and particles, and foundations of relativistic dynamics.This first physical meeting of the Covid-19 era took place 6 - 9 June at Czech Technical University in Prague, as originally planned for 2020. The meeting was divided into seven plenary sessions over four days. As a result of continued travel restrictions in some areas, a small number of talks were delivered by videoconferencing. The papers presented in this volume represent extensions and refinements to the conference talks, building on feedback and discussions associated with the lectures. We once again express our gratitude to Czech Technical University, and especially the local conference chair Petr Jizba, for their generous hospitality.List of Scientific Advisory Committee, International Organizing Committee and Editorial Board of the proceedings, Dedication are available in this Pdf.

Editorial to the Special Theme Sustainability

Sustainability represents a commonly agreed global development goal. It aims at ensuring the quality of life on Earth for current and future generations. Sustainability should thus become the fundamental overarching concept for the efficient/high-quality design and operation of any product or service throughout its lifecycle—focusing on all three pillars of sustainability—social, environmental, and economic. Among the different socioeconomic sectors, dealing with the impacts that the construction sector has is fundamental, as it strongly contributes to many of the pressing issues that need to be addressed. Not only do we need to improve the economic, environmental, and social performance of our built environment, but we also need to be better prepared for new conditions that are appearing as a cause of global challenges (e.g., climate change). The importance of this approach is all the more clear in light of an increasing number of man-made and natural disasters occurring globally. Thus, current developments and changes in the environment and socioeconomic situation require improvements in the technology of different processes that are involved in construction projects. In this context, concrete is a particularly interesting material, because it has a great potential for new technical solutions meeting new requirements, leading to the necessary reduction of environmental impacts and at the same time improvement of social and economic conditions, including safety and reliability during emergency situations. However, considering the huge volume of global concrete production and the negative impacts closely linked to its production, the overall environmental negative impact associated with the construction of concrete structures on a global scale is considerable. In view of the above global situation, it is of utmost importance to focus on the introduction of new production and construction technologies, advanced design techniques and efficient operation, maintenance, and recycling techniques of concrete structures. Concrete mixes, concrete products, and concrete structures should be designed to meet the requirements of sustainability—namely, to minimize their negative impacts and increase the positive impact on society, the environment, and the economy. This could be achieved by increasing the quality and durability of concrete structures throughout their life cycle, through (i) improvements in design methods, (ii) development of concrete mixtures, composite materials, and reinforcement methods, (iii) modernization of concrete technology, (iv) development of integrated design approaches, and (v) innovation in maintenance, repair, demolition, and recycling processes. This requires the involvement of all actors in the construction process, from material manufacturers, designers, and builders to users, and their conviction and initiative in the need to achieve better results in terms of sustainability requirements. This special theme of Structural Concrete journal: Sustainability of Concrete Structures collects a selection of contributions related to different aspects of sustainability showing potential of concrete structures to contribute to the achievement of the Sustainable Development Goals (SDGs) set by the United Nations in 2015 as an action plan until 2030. The content of this special theme volume covers issues related to Life Cycle Assessment of concrete structures, carbon neutrality, use of recycled concrete and other recycled components, optimization of concrete structures, and many other issues bringing the contribution of concrete research and development to SDGs. We trust that the presented selection of articles is of interest to the concrete community focusing on the development of concrete structures toward a sustainable and resilient built environment as a contribution for future generations. Petr HajekDepartment of Architectural Engineering,Faculty of Civil Engineering, Czech Technical University in Prague, Czech Republic; Member of fib COM7, Convener of fib TG7.1: Sustainable Concrete—general framework; Member of fib COM10, TG10.1: Model Code 2020; Member of TG6.3:Sustainability of structures with precast elements and TG1.5:Structural sustainability. Albert de la Fuente AntequeraAssociate Professor, Civil and Environmental Engineering Department, Universitat Politècnica de Catalunya, Barcelona, Spain. Nikola TošićUniversitat Politècnica de Catalunya—BarcelonaTECH (UPC), Barcelona, Spain. Irene JosaDepartment of Civil, Environmental and Geomatic Engineering, University College London (UCL), London, UK. Petr Hajek, Department of Architectural Engineering, Faculty of Civil Engineering, Czech Technical University in Prague, Czech Republic; Member of fib COM7, Convener of fib TG7.1: Sustainable Concrete—general framework; Member of fib COM10, TG10.1: Model Code 2020; Member of TG6.3: Sustainability of structures with precast elements and TG1.5: Structural sustainability. Albert de la Fuente Antequera, Associate Professor, Civil and Environmental Engineering Department, Universitat Politècnica de Catalunya, Jordi Girona 1-3, 08034 Barcelona, Spain. Nikola Tošić, Universitat Politècnica de Catalunya—BarcelonaTECH (UPC), Jordi Girona 1–3, 08034 Barcelona, Spain. Irene Josa, Department of Civil, Environmental and Geomatic Engineering, University College London (UCL), London, UK.