The Experts below are selected from a list of 260970 Experts worldwide ranked by ideXlab platform
Yang Wei - One of the best experts on this subject based on the ideXlab platform.
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Behavior and Modeling of Ultra-High Performance Concrete-Filled FRP Tubes Under Cyclic Axial Compression
Journal of Composites for Construction, 2020Co-Authors: Huiwen Tian, Zhen Zhou, Yang WeiAbstract:Abstract This paper presents an experimental investigation and a stress–strain model for ultra-high performance Concrete (UHPC)-filled fiber reinforced polymer (FRP) tubes under cyclic axial compre...
Ibrahim Hakeem - One of the best experts on this subject based on the ideXlab platform.
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Flexural behavior of hybrid Concrete beams reinforced with ultra-high performance Concrete bars
Construction and Building Materials, 2013Co-Authors: Abul K Azad, Ibrahim HakeemAbstract:As steel-fiber reinforced ultra-high performance Concrete (UHPC) has flexural tensile strength exceeding 30 MPa, a novel idea of utilizing UHPC bars as tension reinforcement to provide flexural strength has been explored in this work. Normal Concrete beam specimens, reinforced with precast deformed UHPC tension bars, were tested in four-point bend test to determine the flexural strength and observe behavior. Test results show that UHPC bars function adequately, developing flexural tensile strength of about 30 MPa at the peak load without any bond slip. The beams show post-peak load ductility with softening in which deflection increases with progressive reduction in residual strength.
M. S. Zahran - One of the best experts on this subject based on the ideXlab platform.
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Response of a new structural ultra-high performance Concrete barrier wall subjected to blast loading
Australian Journal of Structural Engineering, 2020Co-Authors: Ahmed K. Taha, Zhengguo Gao, Huang Da-hai, M. S. ZahranAbstract:Ultra-high performance Concrete (UHPC) is a promising construction of newly developed material. In this study, a nonlinear three-dimensional hydro-code numerical simulation was carried out using au...
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Behaviour of Ultra-High-Performance Concrete Barrier Walls Subjected to Blast Loading
Proceedings of AICCE'19, 2019Co-Authors: Ahmed K. Taha, Zhengguo Gao, Dahai Huang, M. S. ZahranAbstract:In this study, a numerical simulation is conducted using AUTODYN-3D where two Concrete barrier walls are exposed to blast loads. To investigate the effect of using ultra high-performance Concrete in mitigating the effect of blast waves, two numerical models were carried out. The reflected over pressure and post-test damage were analyzed. The results have shown that UHPC barrier walls performed a lot better than NSC barrier walls in blast loading resistance.
Dean Bierwagen - One of the best experts on this subject based on the ideXlab platform.
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Ultra-High Performance Concrete in Iowa
HPC Bridge Views, 2009Co-Authors: Dean Bierwagen, Brian Moore, Ahmad Abu-hawash, Brian KeierleberAbstract:This article describes the use of ultra-high performance Concrete (UHPC) on two bridges in Iowa (United States). The first project was a single-span, 110-ft (33.5-m) long, prestressed I-girder bridge in Wapello County with the girders cast using UHPC. The UHPC mix was used in the fabrication of four modified Iowa bulb-tee beams. The second project was a three-span bridge in Buchanan County whose center span was cast with UHPC using the pi-girder cross section developed by the FHWA and the Massachusetts Institute of Technology. The authors note that the use of the pi-girders provided a complete superstructure system and eliminated the need for an independent deck or wearing surface. The projects used funding support from the Federal Highway Administration's (FHWA) Innovative Bridge Research and Deployment (IBRD) as well as from the Iowa Highway Research Board (IHRB). The authors also briefly describe a third bridge project that is continuing the work with UHPC; this project will use the UHPC mix in a precast deck on a single-span prestressed Concrete beam bridge.
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Ultra High Performance Concrete Design
2006Co-Authors: Brian Moore, Dean BierwagenAbstract:Wapello County and the Iowa Department of Transportation were granted funding through the TEA-21 Innovative Bridge Construction Program (IBRC), for a project that uses ultra high performance Concrete (UHPC). Plans using UHPC in the prestressed Concrete beams for a bridge replacement project in Wapello County, Iowa were prepared and construction for the first UHPC completed bridge in the United States. The Concrete beams are prestressed using 0.6 inch diameter strands and contain no mild reinforcing steel, except to provide composite action with a cast-in-place deck. Discussion of the design efforts of this research project are the focus of this reports. To verify design work, flexure and shear testing were successfully completed in 2005. Three 110 ft. bridge beams were cast in June and July 2005. Construction of the bridge began in August 2005 and was completed in February 2006.
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Ultra High Performance Concrete Highway Bridge
2006Co-Authors: Brian Moore, Dean BierwagenAbstract:Wapello County and the Iowa Department of Transportation were granted funding through the TEA-21 Innovative Bridge Construction Program to demonstrate the use of ultra high performance Concrete (UHPC) in a bridge replacement project. The UHPC in the prestressed Concrete beams is expected to achieve a 28-day compressive strength of up to 30,000 psi. The use of this innovative product in a threebeam cross section is intended to take advantage of the superior strength and to optimize design. The beams will be pretensioned using 0.6-inch diameter strands and without mild reinforcing steel, except to provide composite action with the cast-in-place deck. In Phase I of the multi-phase project, a 71-foot–long test beam will be tested to verify shear and flexural capacities, along with shear testing of smaller beams. If testing efforts are successful, Phase II will include the casting of 111-foot–long beams, followed by the construction of the single span bridge in the spring/summer of 2005. After construction, a monitoring program will be implemented to document the performance of this innovative product.
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Ultra High Performance Concrete Highway Bridge
2005Co-Authors: Dean Bierwagen, Ahmad Abu-hawashAbstract:Wapello County and the Iowa Department of Transportation were granted funding through the TEA-21 Innovative Bridge Construction Program to demonstrate the use of ultra high performance Concrete (UHPC) in a bridge replacement project. The UHPC in the prestressed Concrete beams is expected to achieve a 28-day compressive strength of up to 30,000 psi. The use of this innovative product in a threebeam cross section is intended to take advantage of the superior strength and to optimize design. The beams will be pretensioned using 0.6-inch diameter strands and without mild reinforcing steel, except to provide composite action with the cast-in-place deck. In Phase I of the multi-phase project, a 71-foot-long test beam will be tested to verify shear and flexural capacities, along with shear testing of smaller beams. If testing efforts are successful, Phase II will include the casting of 111-foot-long beams, followed by the construction of the single span bridge in the spring/summer of 2005. After construction, a monitoring program will be implemented to document the performance of this innovative product. A discussion of the design efforts and the current progress of this research project is the focus of this paper.
Ekkehard Fehling - One of the best experts on this subject based on the ideXlab platform.
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Functional microfibre reinforced ultra-high performance Concrete (FMF-UHPC)
Cement and Concrete Research, 2020Co-Authors: Maximilian Schleiting, Alexander Wetzel, P. Krooß, Jenny Thiemicke, Thomas Niendorf, Bernhard Middendorf, Ekkehard FehlingAbstract:Abstract The present paper proposes a novel class of fibre reinforced Concrete, realized by using shape memory alloy (SMA) fibres as reinforcement in ultra-high performance Concrete (UHPC). SMAs can change their geometry imposed by a solid to solid phase transformation triggered by thermal activation or stress. This effect gives the possibility to use one geometry of fibres giving a minimum negative impact on the rheological properties and workability of Concrete and a second geometry of the fibres for maximum positive impact on final mechanical properties. The present work highlights the influence of fibres with various shapes on the workability and the mechanical properties. The impact of SMA fibres in fresh and hardened UHPC compared to UHPC prepared with standard steel fibres is discussed. In light of the advances related to the unique properties of the SMA fibres, this novel Concrete is referred to as “Functional Microfibre reinforced Ultra-High Performance Concrete” (FMF-UHPC).
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Fiber-reinforced ultra-high performance Concrete under tensile loads
DYMAT 2009 - 9th International Conferences on the Mechanical and Physical Behaviour of Materials under Dynamic Loading, 2009Co-Authors: Oliver Millon, Ekkehard Fehling, W. Riedel, Klaus Thoma, M. NöldgenAbstract:Abstract. The present paper deals with the material behavior of ultra-high performance Concrete(UHPC) at high strain rates up to 160 1/s. Static and dynamic material-parameters and the fracturebehavior of a fiber-reinforced ultra-high performance Concrete (mixture B4Q) were investigated. Thematerial shows static compression strength up to 180 MPa and static tension strength up to 9 MPa.With the help of Hopkinson Bar experiments, dynamic material-properties like Young’s modulus,tensile strength and fracture energy are determined. Furthermore, it was possible to record the fail-ure process in small time-steps by application of a new method of fracture observation. Based onthe measured material-parameters, the paper provides “Dynamic Increase Factors” (DIF) ofYoung’s modulus, tensile strength and fracture energy to figure out the differences between UHPC,conventional and high strength Concrete and the potential of the new building material. 1. INTRODUCTIONToday’s constructions tend to be higher, more filigree and more flexible in use. As well, they wereseen to be loaded by new load cases, like dynamic loads from explosions or impacts.Ultra-high performance Concrete is one of the youngest materials within Concrete research. Itsinvestigation offers new applications in the construction of, e.g., high-rise buildings and widelyspanned bridges. For an efficient use of UHPC, the material behavior has to be known. Especiallyin the constructions mentioned above, the consideration of dynamic loads has an increasinginfluence to the calculation of these structures.Thepresentpaper isfocusedondynamicloadsonanexistingultra-high performanceConcrete.The experiments may be seen as one part of an investigation to determine material-parameters fora material model used in numerical simulations.As a new construction material, UHPC is still under investigation concerning static, dynamicand long-time investigation. First results are reported in [4]. However, dynamic behavior of ultra-high performance Concrete and investigations efforts on it are very rarely published.2. TESTING PROCEDURE2.1 Test configuration and specimensTo investigate the material-properties at high strain rates, Hopkinson Bar experiments offer agood possibility to receive exact parameters. With the spallation configuration, which wasestablished by Schuler at EMI [1] and [6], it is possible to measure dynamic Young’s modulus,tensile strength and fracture energy for brittle materials.The specimens require a diameter of 75 mm and a length of 250 mm. The experiments werecarried out in two geometrical configurations. Notched specimens were tested to measure fractureenergy in a predetermined fracture plane. Across this plane, failure process is monitored with anDYMAT 2009 (2009) 671–677 EDP Sciences, 2009DOI: 10.1051/dymat/2009095
