http://hdl.handle.net/11728/5 Σχολή Αρχιτεκτονικής και Γεωπεριβαλλοντικών Επιστημών Wed, 10 Jun 2026 11:54:54 GMT 2026-06-10T11:54:54Z http://hdl.handle.net/11728/13510 Superelastic SMA omega dampers for seismic resilience Hu, Shuling; Zang, Jinmeng; Guo, Tong; Chen, Zhi-Peng; Karavasilis, Theodoros L.; Alam, M. Shahria; Kamperidis, Vasileios C. This paper aims to develop a novel shape memory alloy (SMA) omega damper (denoted as SMA-Ω damper) as a new self-centering component for developing seismic resilient engineering structures. The mechanical behavior and deformation mechanism of the SMA-Ω damper were presented firstly. Experimental studies were subsequently conducted to investigate its hysteretic behavior and failure mode under cyclic loadings. Test results confirmed that the proposed SMA-Ω dampers could achieve reliable self-centering performance with negligible residual deformations under cyclic loadings. Parametric numerical studies were further carried out to understand the strain and stress development in SMA-Ω dampers under cyclic loading and to investigate the influence of design parameters. Parametric analyses revealed that the geometric parameters t, R, r, and d1 governed stiffness, strength, and strain distribution. Larger thickness (t), smaller radii (R, r), and shorter transition lengths (d1) increased stiffness, strength, and energy-dissipation capacity but might induce stress concentration and reduce deformation capacity. Based on the test and numerical results, the design recommendations of SMA-Ω dampers were finally proposed. Tue, 01 Sep 2026 00:00:00 GMT http://hdl.handle.net/11728/13510 2026-09-01T00:00:00Z http://hdl.handle.net/11728/13234 Influence of GGBS and SRA on Early-Age Shrinkage Cracking Potential of Self-compacting Concrete: Insights from Capillary Pressure Jamali, Armin; Mendes, Joao; Nagaratnam, Brabha; Lim, Michael Shrinkage cracking is a prevalent failure mode in concrete structures, particularly those with low volume-to-surface ratios, compromising durability and increasing maintenance costs. Early-age concrete is more prone to shrinkage cracking due to insufficient strength development. Capillary pressure is recognized as the primary driver of shrinkage in concrete; however, conventional sensors can only measure capillary pressure up to 100 kPa for approximately seven hours post-casting, hindering a comprehensive understanding of the relationship between capillary pressure evolution, early-age shrinkage, and cracking potential. This study employs a novel high-capacity tensiometer (HCT) capable of monitoring capillary pressure in concrete up to 2000 kPa, thereby extending measurement capabilities. The effects of ground granulated blast furnace slag (GGBS) and shrinkage-reducing admixture (SRA) on capillary pressure evolution and shrinkage cracking potential were investigated. An extensive experimental program, including measurements of settlement, free and restrained shrinkage, elastic modulus, and tensile strength, was conducted alongside capillary pressure monitoring. Results show that significant shrinkage occurs during initial and final setting times when concrete remains in the plastic phase, with minimal capillary pressure evolution. With further development of capillary pressure, cracking was observed during the semi-plastic phase due to a marked reduction in strain capacity of concrete. The findings also indicate that although GGBS replacement reduces capillary pressure evolution, it is not an effective strategy for mitigating shrinkage cracking due to concurrent reductions in tensile strength. Notably, the effectiveness of SRA is inversely related to GGBS content, necessitating careful consideration in its application. Sat, 30 Aug 2025 00:00:00 GMT http://hdl.handle.net/11728/13234 2025-08-30T00:00:00Z http://hdl.handle.net/11728/13233 Experimental investigation of the embedment strength of laminated veneer lumber (lvl) Vidanalage, Nuwan Padukka; Paraskeva, Themelina S; Kamperidis, Vasileios C Connections in timber structures play a vital role in the stiffness, strength and overall performance of the structure. Embedment properties are of paramount to the overall performance of bolted connections. This study experimentally investigates the performance of embedment strength of LVL manufactured from Nordic Spruce (Picea Abies), utilising 10mm steel dowels. A total of 50 embedment tests were conducted following the half-hole method, as specified in ASTM:D5764−97a. The tests had been performed considering 0°, 45°, and 90° load-to-grain angles, on edgewise orientation of the embedment properties and failure modes were analysed. The experimental embedment strengths were then compared to the respective characteristic embedment strengths proposed in Eurocode 5. While the characteristic embedment strength was 11% lower than the mean embedment strength for load parallel to grain, it overestimated the embedment strength by 9.2% and 7.2% for load-to-grain angles of 45°, and 90°, respectively. Wed, 01 Jan 2025 00:00:00 GMT http://hdl.handle.net/11728/13233 2025-01-01T00:00:00Z http://hdl.handle.net/11728/13232 INVESTIGATION OF A COST-EFFICIENT RETROFITTING STRATEGY OF AN EXISTING REINFORCED CONCRETE BUILDING Ioannou, Anthos; Papamichael, Salomi; Bellos, John In the decades of 1950s, 1960s, 1970s, and 1980s most of the buildings in Cyprus, an island in the Mediterranean Sea which is located to a high seismicity region, were designed without seismic design criteria and detailing rules for structural systems ductility, including a lack of supervision and an inadequate quality control of construction works. Most of those buildings are now dealing with a variety of technical issues due to the irregularity in concrete strength, carbonation of the concrete and steel reinforcement and minimal use of transverse and longitudinal reinforcement of the structural elements. Consequently, it is crucial to identify and retrofit the structures that require seismic upgrading. This work presents a case study of an existing reinforced concrete building in Cyprus that was built in the 1980s and had one of its roof floor cantilevers fail. Firstly, this study focuses on identifying critical failures using nonlinear pushover static analysis, and secondly, it investigates different retrofitting strategies and identifies the most practical and cost-effective approach for seismic retrofitting. These approaches include retrofitting with combined infilled walls and concrete jacketing and combined brace-frame systems and steel jacketing for seismic integrity. Mon, 01 Jul 2024 00:00:00 GMT http://hdl.handle.net/11728/13232 2024-07-01T00:00:00Z