The Experts below are selected from a list of 828 Experts worldwide ranked by ideXlab platform
Assem A. A. Hassan - One of the best experts on this subject based on the ideXlab platform.
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classification of damage in self consolidating Rubberized Concrete using acoustic emission intensity analysis
Ultrasonics, 2020Co-Authors: Ahmed A Abouhussien, Assem A. A. HassanAbstract:Abstract This article presents the results from an experimental study on the application of acoustic emission (AE) analysis to assess the damage progression of self-consolidating Rubberized Concrete (SCRC) mixtures under four-point flexural tests. Self-consolidating Concrete (SCC) mixtures incorporating four variable replacements of crumb rubber (CR) including 0, 10, 20, and 30% were examined to study the effect of CR content on the AE damage detection and quantification capability. Normal Concrete (NC) and normal Rubberized Concrete (NRC) mixtures, with 0 and 40% CR respectively, were also tested for the comparison. Two prism samples were tested from each mixture under monotonic loading conditions, while being constantly monitored via two attached AE sensors until failure. The acoustic emissions obtained from these sensors were related to the damage evolution of the tested prisms from all mixtures. The effects of variable mixture types and CR content on different AE parameters were highlighted. The considered AE parameters included signal characteristics (in terms of signal amplitude) as well as number of AE hits and cumulative signal strength (CSS). In addition, AE b-value and intensity analyses were further performed on the amplitude and signal strength of all AE signals to evaluate the extent of damage by means of three additional AE parameters including b-value, historic index, H (t), and severity, Sr. The outcomes of the AE analysis indicated the usefulness of the considered AE parameters in the detection of two early damage stages including micro- and macro-cracking before failure, irrespective of the CR content. Eventually, the intensity analysis parameters (H (t) and Sr) were correlated to the stages of micro- and macro-cracking in all mixtures for the purpose of damage classification via developed chart.
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The combined effect of crumb rubber and synthetic fibers on impact resistance of self-consolidating Concrete
Construction and Building Materials, 2018Co-Authors: Basem H. Abdelaleem, Mohamed K. Ismail, Assem A. A. HassanAbstract:Abstract This study was conducted to evaluate the impact resistance and mechanical properties of self-consolidating Rubberized Concrete (SCRC) mixtures reinforced with synthetic fibers (SFs). In particular, the investigation aimed to maximize the impact resistance and energy absorption of SCRC mixtures by optimizing the mixture proportions and by using the most appropriate types and volumes of SFs. The study also presented the effect of steel fibers (SLFs) on the impact resistance and mechanical properties of SCRC for comparison. The tested fibers consisted of three types of flexible SFs (19-mm, 38-mm, and 50-mm), two types of semi-rigid SFs (27-mm and 54-mm), and two types of hooked-end SLFs (35-mm and 60-mm). The results indicated that increasing the CR content had a negative effect on the mechanical properties of SCRC mixtures, while the ductility and impact resistance were significantly improved. Using SFs in SCRC mixtures further increased the impact resistance and appeared to alleviate the reduction in splitting tensile strength (STS) and flexural strength (FS) that resulted from adding CR. Although using longer SFs had a negative impact on the fresh properties of SCRC, it greatly improved the mechanical properties and impact resistance of the mixtures. The results also indicated that in the absence of the challenge of achieving self-compactibility, it was possible to develop vibrated Rubberized Concrete with higher percentages of CR and SFs, which in turn resulted in higher improvements in STS, FS, impact resistance, and further reduction in the self-weight of Concrete.
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use of metakaolin on enhancing the mechanical properties of self consolidating Concrete containing high percentages of crumb rubber
Journal of Cleaner Production, 2016Co-Authors: Mohamed K. Ismail, Assem A. A. HassanAbstract:Abstract This research aimed to investigate the mechanical properties of self-consolidating Rubberized Concrete (SCRC) mixtures with high percentages of crumb rubber (CR). The effect of metakaolin (MK) compared to other supplementary cementing materials (SCMs) on enhancing the mechanical properties and stability of SCRC mixtures was highlighted in this research. The variables were percentage of CR (0–50% by volume of sand), type of SCM (fly ash, slag, and metakaolin), binder content (500–550 kg/m3), coarse aggregate size (10–20 mm), and air entrainment. The mechanical properties of the tested mixtures were investigated based on their compressive strength, flexural strength, splitting tensile strength, and modulus of elasticity. The results indicated that using MK improved the mixture stability and particle suspension, which facilitated the development of SCRC mixtures with a high percentage of CR (30%) and with enhanced mechanical properties. Adding entrained air to SCRC mixtures with MK further enhanced the fresh properties and stability, and allowed a higher percentage of CR (40%) to be used safely in SCRC with acceptable stability/strength and with a density of less than 2100 kg/m3. The results also indicated that although SCRC mixtures had slightly higher mechanical properties compared to vibrated Rubberized Concrete (VRC), the problems associated with the fresh properties and stability of SCRC mixtures were reduced in VRC, which allowed up to 50% CR to be used in this mixture with acceptable stability/strength and with further reduction of the mixture density (less than 2050 kg/m3).
Julie E. Mills - One of the best experts on this subject based on the ideXlab platform.
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mechanical performance of frp confined and unconfined crumb rubber Concrete containing high rubber content
Journal of building engineering, 2017Co-Authors: Osama Youssf, Reza Hassanli, Julie E. MillsAbstract:Abstract The use of crumb rubber in Concrete has been practiced for some years. It is an effective environmental approach to use to reduce the amount of scrap tyres in landfills around the world. However, there are concerns about the mechanical properties of crumb rubber Concrete (CRC) and its associated applications. The main purpose of this study is to provide a closer look at different mechanical properties of fibre reinforced polymer (FRP) confined and unconfined CRC with high rubber content. In this study, six Concrete mixtures having 0%, 10%, 20%, 30%, 40%, and 50% rubber content replacement of sand volume were produced. Different mechanical properties including compressive strength, tensile strength, modulus of elasticity, unit weight, impact resistance, water absorption, temperature effect, stress-strain behaviour, and FRP-confinement effect were measured. The results indicated that the use of FRP to confine Rubberized Concrete effectively negates the decrease in strength, and retains the advantages of increased ductility that arise from Rubberized Concrete. In addition, increasing Concrete rubber content from zero to 50% increased its impact resistance by approximately 3.5 times. This indicates promising potential for structural applications, particularly in seismic zones.
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an experimental investigation of crumb rubber Concrete confined by fibre reinforced polymer tubes
Construction and Building Materials, 2014Co-Authors: Osama Youssf, Mohamed A Elgawady, Julie E. MillsAbstract:Abstract Due to the known loss of compressive strength experienced by crumb rubber Concrete (CRC) compared with conventional Concrete, there have been few applications explored to date for the structural use of these materials. This paper describes experimental work conducted to explore the possible future use of 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). The results indicated that the use of FRP to confine Rubberized Concrete effectively negates the decrease in strength, and retains the advantages of increased ductility that arise from Rubberized Concrete. This indicates promising potential for structural column applications, particularly in seismic zones.
Osama Youssf - One of the best experts on this subject based on the ideXlab platform.
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mechanical performance of frp confined and unconfined crumb rubber Concrete containing high rubber content
Journal of building engineering, 2017Co-Authors: Osama Youssf, Reza Hassanli, Julie E. MillsAbstract:Abstract The use of crumb rubber in Concrete has been practiced for some years. It is an effective environmental approach to use to reduce the amount of scrap tyres in landfills around the world. However, there are concerns about the mechanical properties of crumb rubber Concrete (CRC) and its associated applications. The main purpose of this study is to provide a closer look at different mechanical properties of fibre reinforced polymer (FRP) confined and unconfined CRC with high rubber content. In this study, six Concrete mixtures having 0%, 10%, 20%, 30%, 40%, and 50% rubber content replacement of sand volume were produced. Different mechanical properties including compressive strength, tensile strength, modulus of elasticity, unit weight, impact resistance, water absorption, temperature effect, stress-strain behaviour, and FRP-confinement effect were measured. The results indicated that the use of FRP to confine Rubberized Concrete effectively negates the decrease in strength, and retains the advantages of increased ductility that arise from Rubberized Concrete. In addition, increasing Concrete rubber content from zero to 50% increased its impact resistance by approximately 3.5 times. This indicates promising potential for structural applications, particularly in seismic zones.
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an experimental investigation of crumb rubber Concrete confined by fibre reinforced polymer tubes
Construction and Building Materials, 2014Co-Authors: Osama Youssf, Mohamed A Elgawady, Julie E. MillsAbstract:Abstract Due to the known loss of compressive strength experienced by crumb rubber Concrete (CRC) compared with conventional Concrete, there have been few applications explored to date for the structural use of these materials. This paper describes experimental work conducted to explore the possible future use of 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). The results indicated that the use of FRP to confine Rubberized Concrete effectively negates the decrease in strength, and retains the advantages of increased ductility that arise from Rubberized Concrete. This indicates promising potential for structural column applications, particularly in seismic zones.
Ramesh Chandra Gupta - One of the best experts on this subject based on the ideXlab platform.
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properties of high strength Concrete containing scrap tire rubber
Journal of Cleaner Production, 2016Co-Authors: Blessen Skariah Thomas, Ramesh Chandra GuptaAbstract:Disposal of waste tire rubber has become a major environmental issue in all parts of the world representing a very serious threat to the ecology. One of the possible solutions for the use of scrap tire rubber is to incorporate it into Concrete, to replace some of the natural aggregate. This paper presents the results of an experimental research to analyse the suitability of scrap tire rubber as a partial substitute for natural fine aggregate in high strength cement Concrete. Crumb rubber replaced natural fine aggregate from 0% to 20% in multiples of 2.5%. Tests were performed to determine the compressive strength, flexural tensile strength, pull-off strength, abrasion resistance, water absorption and water penetration of these Concrete samples and their microstructures were observed using Scanning Electron Microscopy (SEM). It was observed that the compressive strength, flexural tensile strength, pull-off strength and depth of water penetration of the Rubberized Concrete were less than that of the control mix, while the abrasion resistance and water absorption (up to 10% substitution) exhibited better results than that of the control mix Concrete. Rubberized Concrete may be used in structures where there are chances of brittle failure. Crumb rubber may be utilized in high strength Concrete as a partial substitute for fine aggregate up to 12.5% by weight for obtaining strength above 60 MPa.
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a comprehensive review on the applications of waste tire rubber in cement Concrete
Renewable & Sustainable Energy Reviews, 2016Co-Authors: Blessen Skariah Thomas, Ramesh Chandra GuptaAbstract: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.
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recycling of waste tire rubber as aggregate in Concrete durability related performance
Journal of Cleaner Production, 2016Co-Authors: Blessen Skariah Thomas, Ramesh Chandra Gupta, Vinu John PanickerAbstract:This paper presents the results of an experimental investigation to comparatively study the depth of chloride penetration, resistance to acid attack and macrocell corrosion of Rubberized Concrete and control mix Concrete. Waste tire rubber in the form of crumb rubber was replaced for natural fine aggregates from 0% to 20% in multiples of 2.5%. Analytical studies were performed with Abaqus and the results were compared with compressive and flexural strength obtained in the laboratory. It was observed that the depth of chloride penetration of the Concrete with 2.5–7.5% crumb rubber was lower than or equal to the control mix Concrete. In the water absorption test of acid attacked specimens, gradual increase was observed as the percentage of crumb rubber was increased. After acid attack, more losses in the weight and compressive strength were observed in the control mix Concrete than the Rubberized Concrete. There was no presence of sufficient corrosion in the specimens from the macrocell corrosion test. The analytical results have shown the same trend for compressive strength and flexural tensile strength as obtained in the laboratory. It can be concluded that the Rubberized Concrete is highly resistant to the aggressive environments and can be implemented in the areas where there are chances of acid attack.
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performance of high strength Rubberized Concrete in aggressive environment
Construction and Building Materials, 2015Co-Authors: Blessen Skariah Thomas, Ramesh Chandra Gupta, Priyansha Mehra, Sanjeev KumarAbstract:Abstract Due to the huge increase in the population and number of vehicles, lots of tyres are ending as waste every day. It was estimated that every year almost 1000 million tyres end their useful life and more than 50% are discarded without any treatment. One of the possible solutions for the effective use of waste tyre rubber is to incorporate into cement based materials, to replace some of the natural aggregates. In this study, waste tyre rubber in the form of crumb rubber was used as a partial replacement for natural fine aggregates in high strength cement Concrete. Crumb rubber was replaced for fine aggregates from 0% to 20% in multiples of 2.5%. Tests were done to determine the depth of carbonation, water absorption of acid attacked specimens, compressive strength of acid attacked specimen, variation in weight of acid attacked specimen and chloride penetration of these Concrete samples. From the test results it could be concluded that the high strength Rubberized Concrete are highly resistant to the aggressive environments.
Mohamed A Elgawady - One of the best experts on this subject based on the ideXlab platform.
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strain rate effect on properties of Rubberized Concrete confined with glass fiber reinforced polymers
Journal of Composites for Construction, 2016Co-Authors: Ayman Moustafa, Mohamed A ElgawadyAbstract:AbstractRubberized Concrete possesses viscous damping that is higher than that of conventional Concrete, making it a promising candidate for construction in high seismic regions. Confining Rubberized Concrete with glass fiber–reinforced polymers (GFRP) may result in superior performance. This paper investigates the behavior of Rubberized-Concrete-filled fiber-reinforced polymer tubes (RCFFT) under different strain rates. The Rubberized Concrete had 0, 10, and 20% volume replacement of fine aggregate with shredded rubber. Each test specimen’s behavior was compared to that of conventional Concrete-filled fiber-reinforced polymer tubes (CFFT). The GFRP tubes were fabricated using wet-layup with different numbers of GFRP layers. Three different strain rates (representing static, earthquake, and severe earthquakes) were used to test these specimens under cyclic axial loading. The RCFFT behaved in a manner that was similar to conventional CFFTs. The Rubberized Concrete’s confinement limited the reduction in the...
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an experimental investigation of crumb rubber Concrete confined by fibre reinforced polymer tubes
Construction and Building Materials, 2014Co-Authors: Osama Youssf, Mohamed A Elgawady, Julie E. MillsAbstract:Abstract Due to the known loss of compressive strength experienced by crumb rubber Concrete (CRC) compared with conventional Concrete, there have been few applications explored to date for the structural use of these materials. This paper describes experimental work conducted to explore the possible future use of 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). The results indicated that the use of FRP to confine Rubberized Concrete effectively negates the decrease in strength, and retains the advantages of increased ductility that arise from Rubberized Concrete. This indicates promising potential for structural column applications, particularly in seismic zones.
