http://yetl.yabesh.ir/yetl1/handle/yetl/18992 2026-04-30T00:26:27Z http://yetl.yabesh.ir/yetl1/handle/yetl/4309193 Impact of Concrete Interfaces on the Mechanical Performance of 3D Printed Concrete Structures Qamar Shahzad; Fang-yuan Li This study primarily aims to investigate the influence of concrete interface properties on the anisotropic behavior of three-dimensional (3D) printed concrete (3DPC). A numerical model employing the traction-separation law was developed to capture the detailed behavior of concrete interfaces in 3DPC. To simulate the interfaces, zero-thickness cohesive elements were implemented. Experimental results indicate that horizontal shear deformation at the interfaces between printed layers reduces the compressive strength of 3D printed specimens. Additionally, the flexural strength of the 3D printed sample is mainly influenced by the tensile strength at the midspan. Specimens loaded in the Y- and Z-directions show relatively lower compressive strength but significantly higher flexural strength. Numerical analysis reveals that the number of interlayers and interstrips and shear properties contribute to changes in anisotropy when specimens are subjected to compression and flexure. Recommendations and influencing factors for improving the simulation modeling of 3DPC with anisotropic behavior have been proposed for future studies. 2025-01-01T00:00:00Z http://yetl.yabesh.ir/yetl1/handle/yetl/4309192 Predicting Buildability Using the Surface Texture of 3D Printed Concrete Elements Shanmugaraj Senthilnathan; Benny Raphael The buildability of three-dimensional (3D) printable concrete is commonly measured by the number of layers that can be printed before a collapse or excessive deformations. Buildability depends on rheological properties and their dynamic changes over time due to hydration and evaporation. These variations influence strength development and lead to dimensional changes in individual layers, potentially resulting in failures such as plastic or buckling collapse. Despite the importance of dimensional changes, no studies have monitored these variations in real time to predict buildability failure. In this study, dimensional changes are indirectly assessed by tracking surface texture changes using two-dimensional (2D) cameras and computer vision techniques. Entropy standard deviation (ESD) is introduced as a metric to quantify temporal textural changes and assess buildability collapse. Results indicate that significant variations in surface texture values of individual layers are observed in collapsed elements, allowing for failure prediction before the collapse. The limiting ESD value for a concrete mix can be identified by carrying out a set of experimental prints. This value could be used for the early prediction of buildability collapse. Experimental data show that buildability collapse can be predicted with 100% accuracy by monitoring the maximum ESD values of all the printed layers. Based on this concept, a methodology has been developed for real-time, nonintrusive buildability assessment of 3D printed elements, offering the potential for feedback control systems to enhance quality, reduce material wastage, and improve the sustainability of concrete 3D printing technology. 2025-01-01T00:00:00Z http://yetl.yabesh.ir/yetl1/handle/yetl/4309191 Finite-Element Modeling of Concrete-Filled Steel Tubular Columns under Axial Compression Shengqiang Li; Jin Wang; Jianbo Wei; Tongyu Shi; Yadong Li Concrete-filled steel tubular (CFST) structures involve pouring concrete into steel tubes, which exert a constraining role, significantly enhancing the ductility of the concrete. Such structures are gaining popularity in engineering projects. This study analyzes the steel formwork concrete column that employs a thin-walled form based on previous research on CFST structures. It considers many factors, such as concrete strength, reinforcement diameter, and width-to-thickness ratios, to address the deficiencies in the experimental design scheme through numerical simulation. In addition, standard formulas for existing composite structures are employed to determine the ultimate capacity of the components. The results demonstrated a general consistency in predicted mechanical property outcomes between the nonlinear finite-element analysis and the theoretical calculation. 2025-01-01T00:00:00Z http://yetl.yabesh.ir/yetl1/handle/yetl/4309190 Orientation-Based Analysis of Trombe Walls with Enhanced Glazing Systems across Different Annual Thermal Periods Arash Pourghorban; Hedyeh Asoodeh Trombe walls (TWs) are among the principal energy-efficient passive alternatives for use in building envelopes. This study was carried out as a result of the dearth and limits of previous research on TW glazing units, as well as advancements in glazing technology and the practical restraints to TW orientation. This research focuses on assessing the performance of TWs integrated with advanced glazing systems throughout the entire spectrum of annual thermal periods, with a specific emphasis on understanding the impacts of orientation. To achieve this, we conducted a comprehensive evaluation of a diverse range of TWs paired with advanced glazing units across a wide array of orientations. The annual assessments encompassed heating, cooling, comfort, and overheating periods in a cold climate. This theoretical study employed rigorous methods and approaches, introducing models that consider various advanced structural and spectral specifications of the glazing systems. Notably, this research represents the first instance of conducting holistic orientation studies, thereby contributing novel insights to the field. It was determined that both the orientation and the configuration changes are the most influential on duration changes of the overheating period (27.5% and 24.7%, respectively), while the lowest alteration impacts are on heating (16.7%) and cooling (2.8%) periods, respectively. South orientations (340°, 350°, 0°, 10°, and 20°) achieved optimal performance, reducing heating and overheating durations, while maximizing comfort. Upgrading from single to triple glazing, particularly triple-glazed low-E systems, significantly improved comfort and reduced overheating. The findings emphasize the importance of considering various thermal periods, beyond just heating, in design strategies. 2025-01-01T00:00:00Z