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Articles 1 - 7 of 7
Full-Text Articles in Engineering
Feasibility Of Using Ultra-High-Performance Concrete (Uhpc) As A Repair Material Durability Performance, Rebar Coating, And Bond Characterization, Haitham Hussein
Feasibility Of Using Ultra-High-Performance Concrete (Uhpc) As A Repair Material Durability Performance, Rebar Coating, And Bond Characterization, Haitham Hussein
All Dissertations
Ultra-High Performance Concrete can be a very good material for use in repair works. The ability of chloride ions to pass through repaired concrete layers is suppressed if an impermeable concrete like UHPC is used. However, thickness of the UHPC layer and the orientation of the repair layer relative to the direction of chloride ingress may influence its effectiveness. This study is an attempt to evaluate the effect of varying thicknesses and cross sections areas of UHPC over a precast concrete and the direction of the UHPC layers relative to the direction of chloride ion movement on the resistance offered …
Development Of Ultra High Performance Composite Impact Panels Using Emaa, Jeffrey Hollstein
Development Of Ultra High Performance Composite Impact Panels Using Emaa, Jeffrey Hollstein
Electronic Theses and Dissertations
UHPC with the addition of fibers is recognized for its increased impact resistance compared to typical strength concrete. To further increase the resilience, recent studies have been conducted to reinforce the UHPC with CFRTP on the front and rear face to create sandwich panels. These studies used PETg/E-glass CFRTP bonded to the UHPC using EMAA (Surlyn) in a stamp thermoforming process. Impact tests conducted on these panels have shown that delamination has been the initial and detrimental failure to the sandwich composite. Increasing the composites resistance to debonding will increase the impact energy required to debond the composite. In this …
For The Improvement Of Mechanical And Microstructural Properties Of Uhpc With Fiber Alignment Using Carbon Nanotube And Graphite Nanoplatelet, Huanghuang Huang, Le Teng, Kamal Khayat, Xiaojian Gao, Fazhou Wang, Zhichao Liu
For The Improvement Of Mechanical And Microstructural Properties Of Uhpc With Fiber Alignment Using Carbon Nanotube And Graphite Nanoplatelet, Huanghuang Huang, Le Teng, Kamal Khayat, Xiaojian Gao, Fazhou Wang, Zhichao Liu
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This paper investigates the influence of carbon nanotube (CNT) and graphite nanoplatelet (GNP) on the microstructure and mechanical characteristics of UHPC with steel fiber alignment. The content of CNT and GNP ranged from 0 to 0.3%, by mass of binder. Predominant fiber alignment was manipulated using a flow-induced casting method during UHPC placement. Experiment results indicated that the increase of CNT and GNP content from 0 to 0.3% led to 15%, 40%, and 50% improvement in compressive strength, flexural strength, and T150 (dissipated energy) of UHPC, respectively. Fiber alignment was shown to increase flexural strength and T150 by 30% and …
Use Of Saturated Lightweight Sand To Improve The Mechanical And Microstructural Properties Of Uhpc With Fiber Alignment, Huanghuang Huang, Le Teng, Xiaojian Gao, Kamal Khayat, Fazhou Wang, Zhichao Liu
Use Of Saturated Lightweight Sand To Improve The Mechanical And Microstructural Properties Of Uhpc With Fiber Alignment, Huanghuang Huang, Le Teng, Xiaojian Gao, Kamal Khayat, Fazhou Wang, Zhichao Liu
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This paper studied the influence of pre-saturated lightweight sand (LWS) on the mechanical and microstructural properties of UHPC cast with steel fiber alignment. The changes in hydration kinetics, porosity, nano-mechanical, and mechanical properties were studied. The LWS was used at 0–50% replacement volumes of total sand. Predominant fiber alignment was favored through a flow-induced casting method during casting of flexural prisms. Experiment results showed that the 28-d autogenous shrinkage was decreased from 450 to 275 μm/m with the LWS content increasing from 0 to 50%. The addition of 20% LWS led to maximum increases of 15%, 15%, and 20% in …
Effect Of Carbon Nanotube And Graphite Nanoplatelet On Composition, Structure, And Nano-Mechanical Properties Of C-S-H In Uhpc, Huanghuang Huang, Le Teng, Xiaojian Gao, Kamal Khayat, Fazhou Wang, Zhichao Liu
Effect Of Carbon Nanotube And Graphite Nanoplatelet On Composition, Structure, And Nano-Mechanical Properties Of C-S-H In Uhpc, Huanghuang Huang, Le Teng, Xiaojian Gao, Kamal Khayat, Fazhou Wang, Zhichao Liu
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
This paper studied the influence of carbon nanotube (CNT) and graphite nanoplatelet (GNP) used at 0 to 0.3%, by mass of binder, on composition, structure, and nano-mechanical characteristics of C-S-H of ultra-high performance concrete (UHPC). Hydration kinetics, pore structure, and mechanical properties of UHPC were also investigated. The non-proprietary UHPC was proportioned with 17% lightweight sand for internal curing. Test results indicated that the addition of 0.3% CNT or GNP led to approximately 20 MPa increase in compressive strengths of non-fibrous UHPC mortar and fibrous UHPC (2% steel fibers), compared to those prepared without any nanomaterial. Such enhancement is attributed …
Simplified Analytical Model To Assess Key Factors Influenced By Fiber Alignment And Their Effect On Tensile Performance Of Uhpc, Le Teng, Huanghuang Huang, Kamal Khayat, Xiaojian Gao
Simplified Analytical Model To Assess Key Factors Influenced By Fiber Alignment And Their Effect On Tensile Performance Of Uhpc, Le Teng, Huanghuang Huang, Kamal Khayat, Xiaojian Gao
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
The increase in single-fiber pullout strength usually improves tensile strength and toughness of UHPC. An increase in fiber orientation angle (θ) up to 45° to the direction of pullout load was found to enhance the single-fiber pullout strength. However, such increase in predominant θ value along tensile strength specimens led to a reduction in tensile strength of UHPC. In order to elucidate this controversial observation, analytical models combined with experiments were carried out to assess the key factors influencing the tensile properties of UHPC due to variations of fiber orientation. The test parameters involved the evaluation of the effect of …
Tension-Stiffening Effect Consideration For Modeling Deflection Of Cracked Reinforced Uhpc Beams, Le Teng, Rongling Zhang, Kamal Khayat
Tension-Stiffening Effect Consideration For Modeling Deflection Of Cracked Reinforced Uhpc Beams, Le Teng, Rongling Zhang, Kamal Khayat
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Tension-stiffening effects can significantly influence the flexural performance of cracked reinforced concrete specimens. Such effect is amplified for fiber-reinforced concrete, given the fact that fibers can bridge the cracks. The objective of this study was to develop a model to predict the deflection of cracked reinforced ultra-high performance concrete (R-UHPC) beam elements. The modeling approach characterized the average bending moment of inertia by combining the existing model used for conventional reinforced concrete and the analytical model of stress distribution of UHPC along the cross-section. The finite element analysis (FEA) was employed to evaluate the flexural deflection based on the average …