https://www.um.edu.mt/library/oar/handle/123456789/140901 Fri, 10 Apr 2026 09:16:33 GMT 2026-04-10T09:16:33Z https://www.um.edu.mt/library/oar/handle/123456789/145266 Title: Carbon dioxide sequestration in cement-based materials : carbonation treatment of recycled concrete powder Abstract: Urbanisation growth has brought about (i) an increased use of concrete and consequently an increase in Cem I production which is a major contributor to carbon dioxide (CO2) emissions and (ii) an increase of construction and demolition waste (C&DW). The objective of this study is to explore ways of how to provide a partial Cem I replacement whilst mitigating the problems mentioned above, namely by (i) reducing CO2 emissions by using CO2 captured during cement production in a process to produce supplementary cementitious material and (ii) using recycled concrete from construction and demolition waste in the afore-mentioned process to produce supplementary cementitious material (SCM). This dissertation focuses on the production of recycled concrete powder (RCP) and its activation via different treatment methods, to identify the process which yields the best supplementary cementitious material. Treatment processes researched in this dissertation included calcination, dry carbonation, aqueous carbonation, calcination followed by dry carbonation, calcination followed by aqueous carbonation and limewater soaking followed by dry carbonation. Initially, characteristic testing was done on the various treated powders to determine their physical and chemical properties. This was followed by the assessment of these treated powders when introduced as a 20% cement replacement within the mix design of paste and mortar samples, to determine their fresh, mechanical and durability properties. Calcination treatment achieved a material with the highest pozzolanic activity, as XRD results showed it to have the highest percentages of portlandite, tobermorite, gismondine, and belite at 17.4%, 12%, 2.1% and 17.2% respectively, when compared to the other treated samples. Through XRD, compressive strength and durability testing, it was determined that both dry and aqueous carbonation treatments also yielded materials with potential to be suitable supplementary cementitious material. The combined calcination and carbonation treatments yielded the best chemical and mechanical results due to the formation of both calcite and hydrated phases, creating materials of increased reactivity and strength. The dry carbonation in the calcination and dry carbonation process contributed to produce a material with better properties than that produced in the calcination and aqueous carbonation treatment. In fact, calcination followed by dry carbonation achieved the highest compressive strength of 114.90 MPa at 21 days, surpassing that of the cement control. Description: M.Eng.(Melit.) Thu, 01 Jan 2026 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/145266 2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/145265 Title: Exploring the use of recycled rubber aggregate in seismically resilient concrete structures Abstract: This dissertation investigates the structural performance of rubberised concrete with a focus on its behaviour under static and cyclic loading. Building upon previous research conducted at the Faculty for the Built Environment at the University of Malta, an experimental programme was undertaken to compare a conventional control concrete mix with a rubberised concrete mix incorporating 25% crumb rubber replacement of fine aggregate (CR25). The experimental investigation comprised concrete cube compressive strength tests, static and cyclic reinforced concrete short column compressive strength tests, and static and cyclic reinforced concrete beam flexural tests. The experimental results confirmed that the inclusion of crumb rubber as partial fine aggregate replacement in reinforced concrete structural members leads to 56.39% and 16.16% reductions in compressive and flexural strength respectively when compared to conventional reinforced concrete structural members. However, under cyclic loading, rubberised reinforced concrete specimens exhibited enhanced deformation capacity, improved crack closure during unloading, and more ductile modes of failure. In contrast, conventional reinforced concrete specimens exhibited stiffer responses at the cost of brittle failure with reduced energy dissipation. Cyclic testing highlighted that rubberised concrete experiences accelerated stiffness degradation at higher stress levels relative to lower and moderate stress levels, where they retain superior shape recovery and damage tolerance. Overall, the experimental results obtained indicate that rubberised concrete may not be suitable for strength-critical structural elements, rather excelling in applications where characteristics such as ductility, energy dissipation, and seismic resilience are preferred. This research study demonstrates that rubberised concrete has potential as a specialised structural material in tailored cyclic and seismic environments, provided its use is appropriately supported by further research work. Description: M.Eng.(Melit.) Thu, 01 Jan 2026 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/145265 2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/145263 Title: Tensile behaviour of glue-laminated timber : a comparative analysis between solid and finger-jointed specimens Abstract: This dissertation investigates the structural performance of finger-jointed glue-laminated timber elements, focusing on their behaviour under tensile, creep and cyclic loading scenarios, while also providing comparative analysis of the results with their solid counterparts. The main aim of this study is to evaluate the impact of finger-joints on the ultimate tensile strength and long-term behaviour of glue-laminated timber, as used in structural applications. To accomplish this, dogbone specimens were prepared from a local, commercially purchased glue-laminated beam, in order to have a consistency in the material properties like grade and moisture content. The results demonstrated that the finger-jointed timber specimens, generally exhibited reduced tensile strength when compared to the solid counterparts. Having said this, the finger-jointed specimens showcased satisfactory results under uniaxialtensile conditions, making them suitable for structural applications. Overall, the results of this study show that as long as the structural constraints are appropriately accounted for, the use of finger-jointing technique in timber is still a feasible methodology for sustainable and economical structural applications, since it enables efficient use of material and minimises wastage. Description: M.Eng.(Melit.) Thu, 01 Jan 2026 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/145263 2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/145229 Title: Atmospheric dimension of cinematic space : a study on spatial narrative in cinema Abstract: Over the past century, more sophisticated cinematic productions increasingly sought to use architectural space as an active element, rather than a passive backdrop. This dissertation explores how spatial narratives and atmospheres in cinema serve as visual and sensory tools that convey meaning independently of the spoken score. The study examines these tools through the lens of architectural discourse, to both address and build on, the limited available research on the subject. The study explores the notion of the body both as a mechanism through which space is experienced, as well as the very condition that dictates how space is revealed and inhabited. In cinema the relationship is affected through the spectator’s embodied gaze, objective memory, sensory projection, and mimetic response. The study reveals how architectural space in cinema can perform by visually presenting the time and place the characters inhabit, their socio-political conditions and the ideologies influencing them. Architectonic gestures are used to convey meaning and evoke symbolic associations. When combined with the right atmospheric qualities, they cultivate an emotive disposition in the film’s spectator, prompting a perceptually embodied and intersensory experience. Illuminating architectural space in cinema to be anthropomorphic in nature, proving its function to act as a character in its own right. The embodied poetics of architectural space and its ability to curate intentional narratives and meaning in film are explored through a qualitative, analytical, and phenomenological research methodology. Theoretical research is synthesised with professional insight gathered through a masterclass and open-ended interviews with film professionals. Through their synthesis, a set of analytical parameters are conceived to aid the analysis of Dune, a film by Denis Villeneuve, screened in two halves. This cinematic production, clearly demonstrates space as narratively significant, spatial atmosphere as an effective medium in cinema, and architecture as an anthropomorphic character. Ultimately, architectural cinematic space is portrayed as a tool capable of conveying identity, intent and emotional resonance through spatial narrative, symbolic associations, and atmospheric shifts which help prognosticate the narrative’s trajectory. Description: M. Arch.(Melit.) Thu, 01 Jan 2026 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/145229 2026-01-01T00:00:00Z