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Mohamed A. ElGawady

Bio: Mohamed A. ElGawady is an academic researcher from Missouri University of Science and Technology. The author has contributed to research in topics: Fibre-reinforced plastic & Masonry. The author has an hindex of 30, co-authored 171 publications receiving 3068 citations. Previous affiliations of Mohamed A. ElGawady include Washington State University & University of New Mexico.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the authors explored the possible future use of crumb rubber concrete (CRC) for structural columns by evaluating the use of fibre reinforced polymer (FRP) confinement as a means of overcoming the material deficiencies (decreased compressive strength).

199 citations

01 Jan 2004
TL;DR: In this article, the state-of-the-art on seismic retrofitting of masonry walls with emphasis on the conventional techniques is reviewed and discussed with respect to advantages, disadvantages, limitations, and effect of each retrofitting technique.
Abstract: In many seismically active regions of the world there are large numbers of masonry buildings. Most of these buildings have not been designed for seismic loads. Recent earthquakes have shown that many such buildings are seismically vulnerable and should be considered for retrofitting. Different conventional retrofitting techniques are available to increase the strength and/or ductility of unreinforced masonry walls. This paper reviews and discuses the state-of-the-art on seismic retrofitting of masonry walls with emphasis on the conventional techniques. The paper reviews retrofitting procedures, advantages, disadvantages, limitations, effect of each retrofitting technique.

175 citations

Journal ArticleDOI
TL;DR: In this article, the structural response of multi-story structures to near-fault ground motions, and whether structural response is dominated by the ground motion pulses present in forward-directivity ground motions were investigated.

166 citations

Journal ArticleDOI
TL;DR: In this article, the cyclic behavior of four self-centering bridge bents with different construction details, including external energy dissipaters and neoprene isolation, was presented.
Abstract: This paper presents the cyclic behavior of four self-centering bridge bents with different construction details, including external energy dissipaters and neoprene isolation. The columns of these bents consisted of precast posttensioned concrete-filled fiber tubes (PPT-CFFT). A fifth monolithic moment resisting concrete bent was also tested as a reference specimen. The tests showed that PPT-CFFT bents can be used in bridge construction as a lateral load resistance system. The PPT-CFFT bents without external energy dissipaters displayed a lateral drift of approximately 9.2% without experiencing significant damage or residual displacement. The PPT-CFFT specimen with external energy dissipaters reached a drift angle of 9.2% with some damage. The reinforced concrete specimen failed at a drift angle of approximately 6.9% with substantial damage and residual displacement.

154 citations

Journal ArticleDOI
TL;DR: In this article, the seismic behavior of four hybrid segmental columns consisting of precast posttensioned concrete-filled fiber tubes (PPT-CFFTs) was investigated under increasing lateral loading cycles in a displacement control.
Abstract: Precast segmental construction technique is an excellent candidate for economic rapid bridge construction in highly congested urban environments and environmentally sensitive regions. This paper presents the seismic behavior of four hybrid segmental columns consisting of precast posttensioned concrete-filled fiber tubes (PPT-CFFTs). A fifth monolithic column was also tested as a reference specimen. The columns were tested under increasing lateral loading cycles in a displacement control. The columns had circular cross section diameters of 203 mm and heights of 1,524 mm each. The parameters investigated included different construction details and energy dissipation systems. The PPT-CFFT columns developed lateral strength and deformation capacity comparable to those of the monolithic reinforced concrete column. However, the PPT-CFFT columns dissipated smaller hysteretic energy compared to that of the monolithic reinforced concrete column. Finally, a simple model was used to predict the backbone curves of se...

138 citations


Cited by
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Journal ArticleDOI
TL;DR: A review of modern trends in theoretical developments, novel designs and modern applications of sandwich structures can be found in this paper, where the most recent literature published at the time of writing this review is considered, older sources are listed only on as-needed basis.
Abstract: The review outlines modern trends in theoretical developments, novel designs and modern applications of sandwich structures. The most recent work published at the time of writing of this review is considered, older sources are listed only on as-needed basis. The review begins with the discussion on the analytical models and methods of analysis of sandwich structures as well as representative problems utilizing or comparing these models. Novel designs of sandwich structures is further elucidated concentrating on miscellaneous cores, introduction of nanotubes and smart materials in the elements of a sandwich structure as well as using functionally graded designs. Examples of problems experienced by developers and designers of sandwich structures, including typical damage, response under miscellaneous loads, environmental effects and fire are considered. Sample applications of sandwich structures included in the review concentrate on aerospace, civil and marine engineering, electronics and biomedical areas. Finally, the authors suggest a list of areas where they envision a pressing need in further research.

412 citations

Journal ArticleDOI
TL;DR: In this article, the authors present an overview of some of the research published regarding the fresh and hardened properties of rubberized concrete and show that there is a promising future for the use of waste tire rubber as a partial substitute for aggregate in cement concrete.
Abstract: Disposal of waste tire rubber has become a major environmental issue in all parts of the world. Every year millions of tires are discarded, thrown away or buried all over the world, representing a very serious threat to the ecology. It was estimated that almost 1000 million tires end their service life every year and out of that, more than 50% are discarded to landfills or garbage without any treatment. By the year 2030, there would be 5000 million tires to be discarded on a regular basis. Tire burning, which was the easiest and cheapest method of disposal, causes serious fire hazards. Temperature in that area rises and the poisonous smoke with uncontrolled emissions of potentially harmful compounds is very dangerous to humans, animals and plants. The residue powder left after burning pollutes the soil. One of the possible solutions for the use of waste tire rubber is to incorporate into cement concrete. This paper presents an overview of some of the research published regarding the fresh and hardened properties of rubberized concrete. Studies show that there is a promising future for the use of waste tire rubber as a partial substitute for aggregate in cement concrete. It was noticed from literatures that workable concrete mixtures can be made with scrap tire rubber and it is possible to make light weight rubber aggregate concrete for some special purposes. Rubberized concrete shows high resistance to freeze-thaw, acid attack and chloride ion penetration. Use of silica fume in rubberized concrete enables to achieve high strength and high resistance to sulfate, acid and chloride environments.

408 citations

Journal ArticleDOI
TL;DR: In this article, a series of experiments were carried out to measure workability, setting time, compressive strength, splitting tensile strength, flexural strength and dynamic elastic modulus of AAFS concrete.

267 citations

Journal ArticleDOI
TL;DR: The properties of waste tyre rubber and engineering applications have been previously reported in a range of publications with respect to the environmental, economic, and technical factors as discussed by the authors, with a focus on geotechnical engineering applications, such as earthworks and infrastructure construction.
Abstract: Waste tyres and their accumulation is a global environmental concern; they are not biodegradable, and, globally, an estimated 1.5 billion are generated annually. Waste tyres in landfill and stockpiles are renowned for leaching toxic chemicals into the surrounding environment, acting as breeding grounds for mosquitoes, and fuelling inextinguishable fires. The properties of waste tyre rubber and engineering applications have been previously reported in a range of publications with respect to the environmental, economic, and technical factors. This study compiles and reviews this research with a focus on geotechnical engineering applications, such as earthworks and infrastructure construction. The applications of waste rubber in construction materials includes cementitious concrete, asphalt concrete, and granular materials for earth structures. Crumb rubber, when used as a sand replacement in flowable concrete fill, improved ductility and strength-to-weight ratio. A 40 MPa concrete mix with 0.6% rubber crumb content exhibited optimal strength and air entrainment capabilities, displaying minimal damage after 56 freeze/thaw cycles. Rubber, as a partial replacement for aggregate in road base and sub-base layers, adversely affected the California Bearing Ratio (CBR) of the graded aggregate base course. Rubber-soil mixtures as the interface of foundation and structure yielded a 60–70 % reduction in vertical and horizontal ground accelerations when subjected to earthquake simulation modelling. There is concern regarding the toxicity of waste rubber incorporated products due to leachates of heavy metals and other chemicals common in tyres. Further comprehensive studies in this area are needed. Leachate studies should be conducted under different pH and liquid to solid ratios.

247 citations