Papers by Raafat El-Hacha
The research summarized in this paper focuses on the development of a validated finite element mo... more The research summarized in this paper focuses on the development of a validated finite element model as a design tool for future studies and analysis on a novel hybrid steel-free multi-girder bridge deck system. Good correlation between finite element analysis and experimental test results was found in regards to global behaviour, particularly for predictions of peak load condition and failure sequence in the progressive failure mechanism. The developed finite element model was found applicable for use in future design optimization studies as well as investigations for structural response under additional types of wheel load configurations.
Engineering Structures, Jul 1, 2020
CRC Press eBooks, Aug 18, 2014
Lecture notes in civil engineering, Sep 14, 2022
Canadian Journal of Civil Engineering, 2020
The critical need to enhance existing strengthening methods with more efficient and effective one... more The critical need to enhance existing strengthening methods with more efficient and effective ones has led to the evolvement of smarter and innovative class of materials termed shape memory alloys (SMA). The SMAs possess unique characteristic properties that lie in their ability to undergo large deformations and return to their undeformed shape through stress removal or heating process. Limited research studies conducted using SMAs have shown high potential for their use in building industry. Results presented in this research study are from an experimental study that investigated the compressive behaviour of uniaxial concentrically loaded nickel–titanium (Ni–Ti) SMA-spirally confined RC columns and compared with RC columns confined with conventional carbon fibre reinforced polymer (CFRP) sheets. The compression tests revealed that actively confining the concrete column with Ni–Ti SMA spiral wires increased the performance of the concrete dramatically. Additionally, the active Ni–Ti...
The elastic behavior of concrete structures reinforced internally using Fiber Reinforced Polymer ... more The elastic behavior of concrete structures reinforced internally using Fiber Reinforced Polymer (FRP) is considered the main obstacle in using the FRP reinforcement in the seismic design of structures. The elastic behavior simply means that most of the input energy is stored in the system. This will result in high drift demands in order to accommodate the reduction in the energy dissipation which, in turn, leads to a considerable increase in the construction cost. However, the use of FRP as an internal reinforcement can be advantageous in the sense that it allows the structure to re-center itself to the initial equilibrium position after being subjected to the earthquake motion due to its elastic behavior. In this research, the design of concrete structures reinforced partially using FRP reinforcement is optimized such that to reduce the drift demand and to take advantage of its re-centering ability at the same time. The Capacity Spectrum Method (CSM) is used to evaluate the perfor...
The increasing use of Fibre Reinforced Polymer (FRP) in strengthening Reinforced Concrete (RC) be... more The increasing use of Fibre Reinforced Polymer (FRP) in strengthening Reinforced Concrete (RC) beams necessitates studying its behaviour when subjected to variety of loading types such as fatigue loading. The post-fatigue behaviour of five RC beams is presented in this paper; one un-strengthened beam and four beams strengthened using Near Surface Mounted (NSM) Carbon FRP rods prestressed to 19, 41, and 54% of the CFRP ultimate tensile strain. The fatigue load limits were based on the Canadian Highway Bridge Design Code (CHBDC). The beams were subjected to fatigue loading at a frequency of 2 Hz for 3 million cycles after which they were submitted to post-fatigue monotonic loading up to failure. The post-fatigue test results were compared with similar un-fatigued beams. Test results indicate the minor effect of fatigue loading on the post-fatigue monotonic performance. As compared with the un-fatigued beams, in general, the fatigue loading did not result in significant changes in the ...
ABSTRACT The behaviour of composite beams fabricated from Fibre Reinforced Polymers (FRPs) and Ul... more ABSTRACT The behaviour of composite beams fabricated from Fibre Reinforced Polymers (FRPs) and Ultra-High Performance Concrete (UHPC) under static flexural loading was investigated. The specimens tested included one control beam consisting of a Glass FRP ( ...
ABSTRACT Strengthening using Carbon Fibre Reinforced Polymer (CFRP) has become increasingly impor... more ABSTRACT Strengthening using Carbon Fibre Reinforced Polymer (CFRP) has become increasingly important for strengthening and rehabilitation of Reinforced Concrete (RC) bridges. Limited researches investigated the long-term performance of RC beams strengthened using FRP. In this study, the performance of RC beams strengthened using prestressed NSM-CFRP subjected to fatigue loading is investigated with emphasis on the effect of CFRP geometry. A total of three full-scale 5 m long beams were tested. One control un-strengthened beam, two beams strengthened using NSM-CFRP prestressed to 6800 µ (40 and 42.5% of the ultimate tensile strength of the CFRP strip and rod, respectively); one strengthened using CFRP strips and one strengthened using CFRP rod. All beams were strengthened to have almost the same CFRP axial stiffness. The fatigue rationale is based on the allowed stress range adopted in CSA S6-06 which specifies a maximum stress range of 125 MPa in the tension steel reinforcement. Test results indicated the enhancement of the fatigue performance of the strengthened beams as compared with the un-strengthened beam. It was found that the groove dimensionality, rather than the CFRP geometry, has a detrimental effect on the bond behaviour.
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Papers by Raafat El-Hacha