Conference Proceedings and Presentations

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  • Publication
    Comparing Perceptions of Performance Across Virtual Reality, Video Conferencing, and Face-to-Face Collaborations
    (Institute of Electrical and Electronics Engineers, 2024-01-29) Sanaei, Mohammadamin ; Machacek, Marielle ; Gilbert, Stephen ; Wu, Peggy ; Oliver, James ; Industrial and Manufacturing Systems Engineering ; Virtual Reality Applications Center
    As Computer Mediated Communications (CMCs) advance, businesses have sought alternatives to face-to-face (F2F) meetings to increase productivity for geographically dispersed teams while saving time and money. However, critical differences between CMCs and F2F impact multiple aspects of communication performance. In order to investigate these variations, the current research investigated the communication effectiveness in three distinct scenarios: video conferencing (VC), virtual reality (VR), and face-to-face (F2F). The study involved an electrical circuit repair task and the administration of multiple surveys to gather data from a total of 104 participants, focusing on four dependent variables: shared situational awareness, usability, mental workload, and performance confidence. For all the variables, results showed significantly better scores in VR and F2F conditions than in VC, but there was no significant difference between the VR and F2F conditions. These findings can inform technology developers in improving communication performance in computer mediated contexts, especially by using VR.
  • Publication
    Seismic Column Splice Demands in Braced Frames with Buckling Controlled Braces
    (ISEC Press, 2021) Faytarouni, Mahmoud ; Micheli, Laura ; Seker, Onur ; Akbas, Bulent ; Shen, Jay ; Civil, Construction and Environmental Engineering
    Numerous experimental tests showed that ductile square hollow structural sections (HSS) are susceptible to premature fracture under design-level earthquake ground motions. In addition, recent research has highlighted the vulnerability of column splices to reach their full strength once ductile square HSS braces experience a fracture in braced frames. In this study, the performance of column splices in 5- and 13-story special concentrically braced frames (SCBFs), with X-bracing configuration, located at a distance permitted by the seismic design provisions (i.e., four feet over the concrete floor level), is evaluated under a large number of ground motion excitations. The performance of identical SCBFs with conventional HSS braces and innovative buckling controlled HSS braces is compared. Overall, results from this research indicate that the prevention of brace buckling in SCBFs yields a substantial reduction in the seismically induced bending demands on the column splices, leading to a large margin of safety to remain elastic.
  • Publication
    Adapting Historic Buildings and Sites for Accessibility
    (Association for Preservation Technology International, 1993) Osterberg, Arvid ; Architecture
    Both new and existing restoration and reconstruction projects now require renewed scrutiny due to recent changes in accessibility requirements. Removing barriers from historic (heritage) structures is not simply a matter of installing ramps and widening doorways, measures that often prove to be insensitive to the visual integrity of historic buildings. Recent enactment of new laws and regulations in the United States and Canada now prohibits discrimination on the basis of disability. Additionally, advocacy groups in the two countries are now promoting "universal design," that is, designs that work for all people, regardless of ability level. Universal design provides equal access for the entire spectrum of building users including hearing impaired users, visually impaired users, mobility restricted users, mentally limited users, people of short or wide stature, and individuals who have reduced stamina. Achieving a reasonable degree of accessibility in historically significant, buildings is especially challenging. • Unfortunately, design solutions that compromise the historic character of buildings are commonplace. When the issue is properly addressed with the expertise of a qualified team of consultants and designers, however, intelligent solutions are possible. An intelligent solution is one that achieves accessibility and respects the historic integrity of a building
  • Publication
    Air Void System Requirements for Durable Paving Concrete - Another Look
    (International Conference on Concrete Pavements, 2021-12-31) Sadati, Seyedhamed ; Wang, Xin ; Taylor, Peter ; Kevern, John ; Wang, Kejin ; Institute for Transportation ; Civil, Construction and Environmental Engineering
    The resistance of concrete to freeze-thaw (F-T) greatly depends on the characteristics of the concrete air-void system, such as the air content, size, and distribution. These air-void characteristics are influenced by every step of concrete production, from material selection and mixture proportioning to mixing, and placing. The research presented in this paper summarizes the observations from a comprehensive study that combined the in-situ performance of highway concrete with laboratory investigations. The field investigation involved determining the minimum requirements of air-void systems (AVS) for long-term durability against F-T cycles. In collaboration with several state agencies across the United States and Canada, core specimens were obtained for studying the properties of AVS resulting in different F-T conditions. Hardened air content, spacing factor, and specific surface of air-voids were determined for the extracted cores. The observations were supplemented by data obtained from a wide range of modern paving concrete mixtures. AVS characteristics were investigated using a variety of different techniques in fresh and hardened states. The main outcome of this research is a series of recommendations for minimum fresh and hardened AVS requirements to secure F-T durability.
  • Publication
    Optimized Joint Spacing for Concrete Overlays with and without Structural Fiber Reinforcement
    (International Conference on Concrete Pavements, 2021-12-31) King, Dan ; Gross, Jerod ; Ceylan, Halil ; Chen, Yu-An ; Taylor, Peter ; Civil, Construction and Environmental Engineering
    In thin concrete overlays (10 to 15 cm, 4 to 6 in), field observations have sometimes shown that not all contraction joints activate initially and, in some cases, do not activate until many years after construction. Contraction joints that do not activate may be considered an inefficient design that can lead to unnecessary maintenance efforts, unnecessary costs, and negative impacts on concrete overlay performance. Optimum joint spacing design for concrete overlays may need to be determined based on factors different from those that are currently considered. This study included an analysis for recommended joint spacing using pavement design software, as well as a field review of joint activation in existing concrete overlays using non-destructive testing. Test sections were also constructed in conjunction with new concrete overlay projects to analyze a wider range of variables and study early-age joint activation behavior. The data showed that joint spacing was the most significant factor affecting joint activation in thin concrete overlays. The addition of 2.4 kg/m3 (4 lb/cy) structural synthetic macro-fibers did not affect the rate of initial joint activation compared to overlays without fibers. A design parameter, slab length over the radius of relative stiffness (L/l), was identified to correlate with joint activation rate and timing. Designing joint spacing to achieve L/l between 4 and 7 may provide the desired balance between maximum, timely joint activation and good overlay performance.