New doctoral dissertation

May 15, 2024
VILNIUS TECH Library invites you to follow the published new dissertations. The dissertation „Research of Structure and Durability of Natural Polymer Modified Clays“ prepared by VILNIUS TECH, Yahor Trambitski. The dissertation was prepared in 2020–2024. Scientific Consultant – Dr Olga Kizinievič.

The dissertation was defended at the public meeting of the Dissertation Defence Council of Materials Engineering in the SRA-I Hall of Vilnius Gediminas Technical University at 10 a.m. on 15 May 2024.

The issue of eco-friendly construction is highly relevant nowadays. Unfired clay materials represent a sustainable alternative to other building products, because of their extremely low carbon footprint. Nevertheless, a pressing need remains to enhance their physical, mechanical, and durability characteristics. To save the great ecological potential of unfired clay materials, the most rational way is to modify them with the help of different biopolymers. Therefore, the dissertation considers the possibilities of different biopolymers (polysaccharides – starch, alginate, and chitosan) to modify clay-based building materials. Different preparation technologies (biopolymers gelation and starch retrogradation processes) were used to evaluate the effect of the examined biopolymers on some properties, structure, and durability of clay materials. Biopolymers and their technological parameters were selected according to their origin, chemical structure, and ability to interact with water. The main principle of clay modification, implemented in this research is the complete replacement of water with a biopolymer solution during the manufacturing process of clay composites. The resulting clay composites with starch or alginate solutions exhibit not only improving mechanical properties but also durability, which could make them very attractive for a wide variety of applications from clay masonry units to plasters. The first chapter presents a comprehensive outlook on contemporary trends in the evolution of sustainable clay-based construction materials. Furthermore, it delves into an exploration of the biopolymers, their distinctive characteristics, and the potential avenues for modification. The second chapter is dedicated to the exploration of the raw materials, processing techniques, testing methodologies and equipment used to evaluate the impact of biopolymers on unfired clay composites. The discussion has also focused on the technology of producing gelated biopolymer aqueous solutions, and the possibilities to technologically modify specific biopolymers using the retrogradation process. Also, this chapter presents the methodology of clay composite testing. The third chapter presents the evaluation of the effect biopolymers have on the physical, mechanical, and hygroscopic properties and durability of clay-based composites, describing interaction mechanisms between clay and biopolymers, and the peculiarities of clay composite structure formation. Nine scientific papers were published on the topic of the dissertation: three papers in scientific journals included in the list of Clarivate Analytics Web of Science database with an impact factor, and four papers in conference proceedings included in the Clarivate Analytics Web of Science and Scopus databases, two – in other international databases. A Lithuanian patent based on the results of the dissertation has been granted, and seven reports were presented at national and international scientific conferences.

Doctoral dissertation readers can search via VILNIUS TECH Virtual Library.

 

Related news

From biological bridges to living facades: how civil engineers are reshaping cities
From biological bridges to living facades: how civil engineers are reshaping cities
Modern buildings are no longer made of concrete and steel alone. Biology, artificial intelligence, and sustainable technologies are becoming an integral part of construction, transforming the way cities are designed and built. As technology advances and environmental awareness grows, civil engineers are developing innovative materials and construction methods that are more sustainable, durable, and environmentally responsible. One of these innovators is Assoc. Prof. Dr. Ronaldas Jakubovskis, a researcher at the Faculty of Civil Engineering at VILNIUS TECH, whose work is helping shape the future of urban environments. Turning Research into Real-World Structures Assoc. Prof. Dr. Ronaldas Jakubovskis serves as a Senior Researcher at the Laboratory of Innovative Building Structures, where his work focuses on developing advanced structural solutions through experimental testing, laboratory research, and numerical modelling. However, innovation rarely begins with a completely new idea. According to Dr. Jakubovskis, much of the research process is dedicated to analysing existing materials and construction technologies to understand how they can be improved. [caption id="attachment_88679" align="alignnone" width="2560"] Ronaldas Jakubovskis[/caption] „The most rewarding moment is when years of laboratory research become a real structure that can be built and experienced in a natural environment,“ he says. Although he works in academia, Dr. Jakubovskis sees himself primarily as a civil engineer supporting other civil engineers. While structural designers and project managers oversee the overall design of buildings and infrastructure – determining layouts, dimensions, and cost-effective construction solutions – researchers provide the specialised expertise needed to develop new materials and solve complex engineering challenges. „Practising engineers often don't have enough time to investigate highly specialised solutions or explore entirely new materials – that's where we come in. Sometimes we analyse complex structural behaviour through numerical modelling, and sometimes we investigate how emerging materials can be applied in construction. In my opinion, research engineers don't quite fit the traditional stereotype of scientists wearing white lab coats or solving abstract equations all day. Our work is highly practical—we often design, manufacture, and physically test new structural systems ourselves.“ Engineering That Leaves a Visible Legacy Among the projects he is most proud of is the Biological Bridge installed at the Kairėnai Botanical Garden, as well as the Living Concrete wall currently being developed for the rooftop of the Lithuanian National Drama Theatre. Both projects demonstrate how engineering can merge sustainability, science, and architectural design. „These projects represent the culmination of years of laboratory work and numerical modelling. They are demonstration structures that show what is possible when innovative materials meet advanced engineering. I also value their aesthetic qualities. Designing complex organic forms allows you to feel a little like a sculptor creating a work of art.“ Looking ahead, Dr. Jakubovskis believes his greatest achievements are still to come. His long-term vision is to create buildings with façades intentionally designed to be colonised by living organisms, allowing them to interact naturally with their environment while providing ecological and functional benefits. [caption id="attachment_88005" align="alignnone" width="2560"] Ronaldas Jakubovskis[/caption] „We are currently developing larger demonstration projects, seeking research funding, and expanding international collaborations. I believe that within the next five years, we'll be able to stand in front of one of these buildings and say: this is a significant achievement.“ A Profession That Will Still Matter in 100 Years For Dr. Jakubovskis, choosing civil engineering was an easy decision. Since childhood, he enjoyed watching buildings rise from the ground and observing construction sites and heavy machinery. „You don't need extraordinary dreams to become a civil engineer. If you want to build, you become an engineer. It's not like travelling to space or conducting research in Antarctica.“ What motivates him most is the opportunity to create structures that remain valuable for decades – or even centuries. „Every civil engineer feels proud when driving past a bridge or building they helped design, and they will always point it out to everyone in the car,“ he says with a smile. His own career began in structural design after completing his third year of university. He later pursued doctoral studies focusing on the cracking behaviour and deformation of reinforced concrete structures before returning to industry. Eventually, an invitation to rejoin VILNIUS TECH brought him back to academia. „I came back, and today I'm doing exactly what I truly enjoy.“ Advice for Future Engineers As both a researcher and lecturer at the Faculty of Civil Engineering, Dr. Jakubovskis emphasises that a university education is essential for anyone pursuing a career in civil engineering. „It would be extremely difficult to master this profession through self-study alone. Should you begin with theoretical mechanics, mechanics of materials, or structural mechanics? University programmes are carefully designed so that knowledge develops step by step, preparing graduates to become highly qualified professionals.“ He also offers practical advice to prospective students: „Don't be afraid of mechanics, physics, or mathematics. Every semester, identify a few key subjects, understand them thoroughly, and make sure you truly master them. Once those foundations are in place, everything else builds naturally.“ Industry Investing in Future Engineers Preparing the next generation of civil engineers is a shared responsibility between universities and industry. As digitalisation, artificial intelligence, and emerging technologies continue to reshape construction, employers increasingly recognise the importance of investing in future talent. The Faculty of Civil Engineering at VILNIUS TECH enjoys long-standing partnerships with the Lithuanian Builders Association (LSA) and the Lithuanian Association of Civil Engineers (LSIS), both of which actively support education and professional development. The Faculty's industry partners – including Hanner, Gilesta, and Alvora – offer scholarships to first-year Civil Engineering students, helping talented young people begin their studies. Other partners, such as Naresta, PST Group, HSC Baltic, and numerous construction companies, contribute by delivering guest lectures, presenting real-life projects, and inviting students to construction sites, where they gain first-hand experience of modern engineering practice. These close collaborations ensure that VILNIUS TECH programmes remain aligned with industry needs while providing students with practical knowledge, professional skills, and valuable connections long before graduation. Learn more about Civil Engineering studies at VILNIUS TECH and discover how you can help shape the cities of tomorrow.
More
Discover JSTOR: Explore Scholarly Journals and Primary Sources
Discover JSTOR: Explore Scholarly Journals and Primary Sources
With exams behind you and more time available for independent exploration, we invite you to take advantage of VILNIUS TECH’s subscribed database, the JSTOR Archival Journals and Primary Sources Collection. This collection offers not only scholarly articles but also original historical documents, images, primary sources, manuscripts, plant specimens, cultural heritage objects, and other unique materials. JSTOR also provides access to more than 4,000 academic journals covering a wide range of subjects, including literature, history, politics, psychology, economics, business, life sciences, natural sciences, the arts, and more. By combining scholarly articles and primary sources on a single platform, JSTOR makes it easier to discover new research perspectives, uncover unexpected connections across disciplines, and enrich both study and research activities. What can you discover in JSTOR? Nineteenth-century pamphlets on technological innovations and social change. Historical letters, speeches, and documents. Millions of plant specimens from around the world. Photographs, maps, and 3D models of cultural heritage objects. Works of art, posters, and historical photographs. More than 4,000 academic journals across a wide range of disciplines. Access is available from VILNIUS TECH computer network or via VPN. As a security measure, two-factor authentication is additionally required (i.e. verification from mobile device app or by call).
More