The Experts below are selected from a list of 3729 Experts worldwide ranked by ideXlab platform
Satish Udpa - One of the best experts on this subject based on the ideXlab platform.
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Microwave NDE for Reinforced Concrete
AIP Conference Proceedings, 2006Co-Authors: Kavitha Arunachalam, Vikram R. Melapudi, Edward J. Rothwell, Lalita Udpa, Satish UdpaAbstract:Nondestructive assessment of the integrity of civil structures is of paramount importance for ensuring safety. In concrete imaging, radiography, ground penetrating radar and infrared thermography are some of the widely used techniques for health monitoring. Other emerging technologies that are gaining impetus for detecting and locating flaws in Steel Reinforcement Bar include radioactive computed tomography, microwave holography, microwave and acoustic tomography. Of all the emerging techniques, microwave NDT is a promising imaging modality largely due to their ability to penetrate thick concrete structures, contrast between Steel reBar and concrete and their non‐radioactive nature. This paper investigates the feasibility of a far field microwave NDE technique for reinforced concrete structures.
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Microwave NDT of cement-based materials using far-field reflection coefficients
NDT & E International, 2006Co-Authors: Kavitha Arunachalam, Vikram R. Melapudi, Lalita Udpa, Satish UdpaAbstract:Periodic assessment of ageing civil structures is important for structural integrity and public safety. Numerous destructive and non-destructive techniques employing different energy sources have been proposed for structural health monitoring. Amongst the non-destructive evaluation techniques proposed for monitoring material strength and contents of concrete structures, techniques employing microwaves offer distinct advantages in that they are non-radioactive and provide good penetration, excellent contrast between Steel Reinforcement Bar and concrete, and insensitivity to ambient temperature. In this paper, the feasibility of a far-field microwave NDE technique for concrete imaging is investigated via numerical simulations and experiments on cement based samples using far-field microwave reflection coefficients.
Kay Wille - One of the best experts on this subject based on the ideXlab platform.
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Influence of volume fraction and orientation of fibers on the pullout behavior of Reinforcement Bar embedded in ultra high performance concrete
Construction and Building Materials, 2017Co-Authors: Manish Roy, Corey Hollmann, Kay WilleAbstract:Abstract An experimental investigation was carried out to evaluate the effect of fiber volume fraction (Vf) and fiber orientation on the pullout behavior of Steel Reinforcement Bar embedded in Ultra High Performance Concrete (UHPC). The experiments were performed using pullout specimens under tensile stresses and low concrete cover. It was found that the peak pullout load increased with the increase in Vf. When Vf was kept constant at 2%, it was observed that the specimens with perpendicular and parallel fiber orientation with respect to the reBar direction recorded the highest and the lowest pullout load, respectively. Finally, an empirical model equation was developed to predict the bond strength values.
Pham Hoang - One of the best experts on this subject based on the ideXlab platform.
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Ultra high Performance Fiber Reinforced Concrete Panel Subjected to Severe Blast Loading
'Defence Scientific Information and Documentation Centre', 2020Co-Authors: Mai Viet-chinh, Vu Ngoc-quang, Nguyen Van-tu, Pham HoangAbstract:Experimental studies play a crucial role in shedding light on the dynamic behaviour of structures under blast loading. However, high costs and complicated technical requirements, particularly for full-scale structures, are still huge disadvantages to conduct such a series of tests. Hence, the finite element method is much needed to provide supplementary information to previous experiments and to enable further parametric studies without testing. This article presents a numerical investigation carried out to understand the behaviour of ultra high performance fiber reinforced concrete (UHPFRC) panels under severe blast loading. The authors designed a subroutine with eight numbers of solution-dependent state variables, 32 mechanical constants, integrated with the Abaqus program to analyze the dynamic behaviour of UHPFRC against multiple blast impacts, using the Johnson-Holmquist 2 damage model incorporating both the damage and residual strength of the material. The subroutine was validated by comparing the simulation results with test results. For the purpose of estimating the structural response of the UHPFRC panel subjected to blast loading, other studying scenarios were considered by varying input parameters, including the thickness of the panel, stand-off distance, and Steel Reinforcement Bar volume. The variations in deflection, strain, and damage of the UHPFRC panel, as well as the Steel Reinforcement strain, were also evaluated. Through important obtained results, the UHPFRC panel is strongly recommended for a protective Barrier installed in the vicinity of critical infrastructure against severe blast loadin
Kavitha Arunachalam - One of the best experts on this subject based on the ideXlab platform.
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Microwave NDE for Reinforced Concrete
AIP Conference Proceedings, 2006Co-Authors: Kavitha Arunachalam, Vikram R. Melapudi, Edward J. Rothwell, Lalita Udpa, Satish UdpaAbstract:Nondestructive assessment of the integrity of civil structures is of paramount importance for ensuring safety. In concrete imaging, radiography, ground penetrating radar and infrared thermography are some of the widely used techniques for health monitoring. Other emerging technologies that are gaining impetus for detecting and locating flaws in Steel Reinforcement Bar include radioactive computed tomography, microwave holography, microwave and acoustic tomography. Of all the emerging techniques, microwave NDT is a promising imaging modality largely due to their ability to penetrate thick concrete structures, contrast between Steel reBar and concrete and their non‐radioactive nature. This paper investigates the feasibility of a far field microwave NDE technique for reinforced concrete structures.
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Microwave NDT of cement-based materials using far-field reflection coefficients
NDT & E International, 2006Co-Authors: Kavitha Arunachalam, Vikram R. Melapudi, Lalita Udpa, Satish UdpaAbstract:Periodic assessment of ageing civil structures is important for structural integrity and public safety. Numerous destructive and non-destructive techniques employing different energy sources have been proposed for structural health monitoring. Amongst the non-destructive evaluation techniques proposed for monitoring material strength and contents of concrete structures, techniques employing microwaves offer distinct advantages in that they are non-radioactive and provide good penetration, excellent contrast between Steel Reinforcement Bar and concrete, and insensitivity to ambient temperature. In this paper, the feasibility of a far-field microwave NDE technique for concrete imaging is investigated via numerical simulations and experiments on cement based samples using far-field microwave reflection coefficients.
Manish Roy - One of the best experts on this subject based on the ideXlab platform.
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Influence of volume fraction and orientation of fibers on the pullout behavior of Reinforcement Bar embedded in ultra high performance concrete
Construction and Building Materials, 2017Co-Authors: Manish Roy, Corey Hollmann, Kay WilleAbstract:Abstract An experimental investigation was carried out to evaluate the effect of fiber volume fraction (Vf) and fiber orientation on the pullout behavior of Steel Reinforcement Bar embedded in Ultra High Performance Concrete (UHPC). The experiments were performed using pullout specimens under tensile stresses and low concrete cover. It was found that the peak pullout load increased with the increase in Vf. When Vf was kept constant at 2%, it was observed that the specimens with perpendicular and parallel fiber orientation with respect to the reBar direction recorded the highest and the lowest pullout load, respectively. Finally, an empirical model equation was developed to predict the bond strength values.