Plenary lectures

Prof. Mostafa Fahmi HASSANEIN, Tanta University, Egypt
Invited Lecture: Confinement-Based Direct Design of Different Concrete-filled Steel Tubular Columns - A New Method of Design

Abstract of the presentation: The presentation summarises the efforts done to propose a new design method for concrete-filled steel tubular (CFST) columns under axial compression, which is called as the Confinement-Based Direct Design method. First, a thorough review of existing test information is collected and discussed for each cross-section under consideration, and the most salient parameters in terms of the overall strength are identified. There are a large number of influential and inter-related parameters which affect the load-carrying capacity of different cross-section types of CFST columns, including the geometry, cross-sectional shape, type of steel, concrete strength, boundary and loading conditions, and type of fibre-reinforced polymer sheets. Generally, it is shown that existing design approaches do not reliably predict the strength for the full range of possible parameters. The method accounts for the various complexities which affect the behaviour, yet presents a user-friendly, performance-based design expression. It is based on an evaluation of the lateral confining pressure provided by the steel tubes (and the FRP if exists) to the concrete core. This is employed in the confinement-based direct resistance calculations. The design methods are validated by comparing its capacity predictions with the collected datasets of the experimental results and also with other design models available in the specification as well as the literature. The results show that the proposed models provide much accurate strength predictions with greater reliability for the full range of parameters examined, than existing methods. Currently, this design method covers the circular and square concrete-filled double-skin tubular columns with ordinary or rubberised concrete, circular and square CFST short columns strengthened externally with carbon or glass fibre reinforced polymer sheets (CFRP or GFRP, respectively), CFST with welded-stiffened square steel sections, CFST with cold-formed stiffened square steel sections and circular steel tube confined concrete (STCC) short columns.

Prof. Aleksandar SEDMAK, Faculty of Mechanical Engineering University of Belgrade
Invited Lecture: Structural integrity assessment of historically important constructions – case studies

Abstract of the presentation:  In this presentation historically important constructions are analysed from structural integrity point of view. Three case studies are presented: The first one is the dome of the “Hall 1 of the Belgrade Fair”, Serbia, made of pre-stresses concrete, designed in 1955-1957, still holding the world record in self-supporting structures. Besides stress calculations done by FEM recently, which proved excellence in design made almost 70 years ago without any computer, FEM was also used to simulate crack growth in a support column. Based on these calculations, the Failure Assessment Diagram (FAD) was provided, indicating high crack resistance of supports. The second one is the Old stone bridge in Mostar, Bosnia and Hercegovina, made in XVI Century, with some details about its sanation in 1953-1955, its destruction 1993 and reconstruction in 2006. Finally, a detailed structural integrity assessment of the historical bridge in Transylvania is presented, including FEM analysis, FAD and fatigue crack growth simulation for typical cracks, with a proposed solution based on this analysis – retrofitted bridge with added box girder beam along its central area.

Prof. Baoxin Qi, School of Civil Engineering, Shenyang Jianzhu University, Liaoning Shenyang, China
Invited Lecture: Study of impact damage in PVA-ECC beam under impact loading based on piezoelectric sensing technology

Abstract of the presentation:  Coming soon.

Prof. Harish Chandra ARORA,  Central Building Research Institute Roorkee, India
Invited Lecture: Durability and Bond behaviour of composite strengthened RC structures

Abstract of the presentation: Coming soon.

Prof. Marijana HADZIMA-NYARKO,  Faculty of Civil Engineering and Architecture, Josip Juraj Strossmayer University of Osijek, Croatia
Invited Lecture:  Collection of building data for seismic vulnerability assessment
Abstract of the presentation:  Since earthquake risk refers to the expected losses for a given element of risk exposure over a given future period, one of the essential components is exposure, i.e. the database of buildings. The presentation will focus on on-site data collection. Field data collection is a daunting task as it requires a significant investment of time and resources for the research in terms of preparing and conducting the fieldwork, calculations and processing the collected data, managing numerous data repositories (e.g. in archives and government institutions) to resolve uncertainties from the field. However, the most accurate assessment of seismic vulnerability is only possible if the most accurate building data is available. This presentation will provide answers to the questions of which important building characteristics should be recorded and how uncertainty in data collection can be reduced. For this purpose, the Erasmus+ KA2 Strategic Partnerships project "Intelligent Methods for Structures, Elements and Materials - IM4StEM" was launched, which, among other things, collects data on urban buildings in several states, including Brasov, Romania.
Prof. Haixia Zhang,  School of Civil Engineering, Shenyang Jianzhu University, Liaoning Shenyang, China
Invited Lecture:  Analysis on dynamic behaviour of simply supported GFRP tube-encased steel concrete members under lateral impact loads
Abstract of the presentation: Coming soon.
Prof. Dorina Nicolina ISOPESCU,  Faculty of Construction and Building Services from the "Gheorghe Asachi" Technical University of Iași
Invited Lecture:  The future in constructions. Challenges and opportunities
Abstract of the presentation: The construction industry today is much different than it was a few decades ago. Although it is complicated to predict exactly how the future will unfold, it is necessary to try to anticipate and prepare for what is coming. The industrialization of the construction process is the answer to the requirements of future beneficiaries who want a balance between reduced execution time, optimal cost per objective and quality at high standards. To meet all these user requirements, only industrialized production, which involves standardization and prefabrication through modularization, digitalization and robotization, can be the solution. The increase in demand for housing or constructions with multiple and diverse functions, the need for a major renovation of the existing built stock, support the fact that there is a future in construction. Climate change and global warming raise new demands on specialists, which implies a new approach to all factors involved in the construction of buildings, from designers to those who execute them, as well as users. In other words, or rather in a few words, the future of construction lies in the ability of specialists to develop new solutions and calculation models, specialized software and large spaces for data storage, to invent new materials or execution technologies, so that the requirements of sustainability and environmental protection to be met.
The construction sites of the future will be sites where advanced technologies such as drones, autonomous vehicles, remotely controlled mobile equipment, 3-D printing, and building information modeling (BIM) systems will be used. There are certainties and studies carried out, such as these technologies will increase the quality of the final product, generically called construction, while at the same time reducing the costs of construction projects.
Construction materials such as stone, concrete, steel, wood and masonry have been traditionally used since ancient times in the construction of buildings, due to their structural performance, but also their costs. In recent decades, new materials have been developed, known as composite materials (engineered materials), which are a combination of natural and/or artificial materials, with the resulting material showing superior structural performance compared to the components. At the same time, it is noted that recycled and reclaimed building materials are widely available. The buildings and construction sector accounted for in 2018, 36% of final energy consumption and 39% of carbon dioxide (CO2) emissions, of which 11% resulted from the manufacture of construction materials and products such as steel, cement and glass. In this context, the building materials of the future will be those engineered materials that will meet the requirements of sustainability and environmental protection, modern building materials with low CO2 emissions throughout their value chain.
In conclusion, the opportunities for future development of the construction sector are already substantiated, the challenges will materialize through the use of prefabricated elements on a large scale. The concept of prefabricated constructions is not new, being used in many countries, including Romania, but this will develop on the support provided by the new generation of materials and equipment. The presented case studies highlight these aspects, as well as the fact that there is a tendency to extend industrialized execution technologies to all types of buildings, financial efficiency being an essential factor for promotion and implementation, in addition to the positive response to the many requirements of the principles of sustainability and environmental protection
Assist. Prof. Jelena PEJOVIĆ,  Faculty of Civil Engineering, University of Montenegro
Invited Lecture:  Development of National Seismic Risk Assessment for Montenegro: Building Exposure Modelling
Abstract of the presentation: Seismic risk assessment in Montenegro has been a pressing concern since the devastating earthquake of 1979, which prompted initial seismic risk studies to develop a spatial plan for Montenegro. Subsequently, concerted efforts were made to mitigate seismic risks and regulate the construction of earthquake-resistant structures. Vulnerability studies were conducted based on damage observations from the 1979 earthquake. However, since that period, the seismic risk in Montenegro has increased significantly due to rapid urbanization and expanded construction of buildings, especially in coastal zones with high seismic hazard levels. Unfortunately, the seismic risk study in Montenegro was not updated until 2021, when extensive research was done as part of a project funded by the European Commission to develop a National Risk Assessment (NRA) led by the Department of Civil Protection. As part of this comprehensive study, the seismic risk assessment was done following EU guidelines to ensure consistency and comparability in prevention, preparedness and planning with EU member states. The development of the NRA faced numerous challenges, primarily stemming from data deficiencies, notably in the building exposure model. In this presentation, the methodology used for seismic risk assessment focusing on the main uncertainties in used SERA building exposure data is presented. Furthermore, it introduces a refined SERA exposure model designed for building typologies in the northern region of Montenegro. Also, it outlines ongoing and future research endeavours related to the continuous enhancement of the exposure model.
Prof. Yoshikazu KOBAYASHI,  College of Science and Technology, Nihon University, Japan
Invited Lecture: Soundness evaluation of thick plate structure based on Pseudo 3D Acoustic Emission Tomography
Abstract of the presentation: Acoustic Emission Tomography (AET) identifies the elastic wave velocity distribution by using the arrival times of elastic waves. In the application of AET to the soundness evaluation of thick plate structures, the evaluation has been mainly performed in two-dimensional manner due to the limitation of the computational resources and observation conditions. However, the three-dimensional effect is not negligible in the cases of thick plate structures, e.g., concrete bridge deck, and the elastic wave velocity distribution is inaccurately identified in the cases as consequence on the basis of two-dimensional modeling. Although three-dimensional modeling is required to avoid this problem, it needs huge computational resources in comparison with two-dimensional analysis if the size of the model is relatively large and more sensors are required in the thickness direction nevertheless there are difficulties to install the sensors in that manner. Thus, Pseudo-3D model is implemented in AET to avoid the difficulty. The proposed method is validated on the basis of numerical investigations.
 
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