Ahmed Abdelaziz Elbarbary | Albaha University (original) (raw)

Papers by Ahmed Abdelaziz Elbarbary

Curved and Layered Structures, 2024

The main idea of this research is to manufacture plastic fibers (PFs) by recycling harmful plasti... more The main idea of this research is to manufacture plastic fibers (PFs) by recycling harmful plastic waste after washing it with water and drying it, then cutting it into strips and immersing them in liquid nitrogen, using a rotating iron basin mixer containing iron balls that touch these strips, producing fibers that are woven later to be similar to carbon-fiber-reinforced polymer (CFRP). This process is the first in the world, and the cost of manufacturing these fibers is very low compared to the cost of producing CFRP, as the cost of producing these fibers is 25 times less than the cost of producing CFRP. All the physical, chemical, and mechanical properties of the manufactured PFs were investigated and compared with the properties of CFRP. In this research, it was found that the manufactured PFs have properties similar to the properties of CFRP. The experimental work consists of casting five reinforced concrete beams with a cross-section of 125 mm × 200 mm and a length of 1,200 mm. They were divided into two groups, each group containing two beams, one of which was reinforced by CFRP, and the other was repaired by CFRP. The second group also contained two beams, one of which was reinforced by PF, and the other was repaired by PF, while the fifth beam was a control beam. From the experimental results, a significant increase in the ultimate load of the beams reinforced by PF or CFRP ranged between 45.45 and 51%, respectively. This is due to the role of manufactured PFs and CFRP in restricting the width of cracks in the bending zone of reinforced or repaired concrete beams. Also, there was a change in the type of failure when changing the type of fiber, where the failure was ductile and gradual in the beams reinforced or repaired with manufactured PFs, unlike what was in the beams reinforced or repaired by CFRP, where the failure was brittle and sudden.

American Journal of Engineering Research, 2024

The negative consequences that buildings and structures may have on the environment include water... more The negative consequences that buildings and structures may have on the environment include water on energy consumption. Since the GPSS Green Pyramid Scoring System in Egypt not fully address the five pollution, energy consumption, waste generation during the construction period, and carbon dioxide gas emissions.

INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING AND BUSINESS SCIENCES (IJAEBS), 2023

A modified Strut-and-Tie model (MSTM) was developed for fibrous deep beams to include the contrib... more A modified Strut-and-Tie model (MSTM) was developed for fibrous deep beams to include the contribution of steel fibers in the internal resistance for compression and tension. The proposed (MSTM) calculates the ultimate loads for several experimental results. The ratio between experimental results and MSTM predictions (Pu(EXP) /Pu(MSTM)) for 79 specimens is 1.20%. The results of the Strut-and-Tie for the American Code (Pu(ACI)) and Egyptian Code (Pu(ECCS)) are more conservative. The inclusion of steel fibers increases the shear capacity of deep beams by 13% and 19% respectively in compassion with ACI Code and the Egyptian Code. The ratio for (Pu(EXP) /Pu(ACI)) and (PuEXP /Pu(ECCS)) are 1.36 and 1.43, respectively. The predictions of (MSTM) are consistent, accurate, and have a great degree of validation for (HSSFRC) deep beams with different geometrical properties, concrete compressive strength, fibers, main and web steel ratios.

Journal of University of Babylon for Engineering Sciences (JUBES), 2023

Humans need to keep on the clean environment in order to refine suitable life for the next genera... more Humans need to keep on the clean environment in order to refine suitable life for the next generators. Where, the different industries formed by human, cause the environmental pollution by landfill with wastes produced from it and cause the consumption of fresh raw materials. One of these industries, is gypsum plaster industry. Where, a large amount of gypsum plaster waste is produced from different fields that use the gypsum plaster. Therefore, it is necessary to work on reduction of these wastes by reusing or recycling them with the least costs and procedures. This study aims to review the ways used to reduce gypsum waste amount and to figure ant the best among them. It can be concluded that the best ways to reduce the gypsum waste amount are by recycling it with the least costs or reusing it without any additional procedures.

Journal of Building Engineering, 2023

he utilization of photochromic cement and photochromic polymeric (epoxy and polyester) mortars in... more he utilization of photochromic cement and photochromic polymeric (epoxy and polyester) mortars in building applications is explored in this study. In order to achieve the objective, photochromic cement, epoxy, and polyester mortars were fabricated, and their performances were
comparatively evaluated. The physical and mechanical properties, including water absorption,
compressive strength, and ultrasonic pulse velocity, as well as the phase and microstructural
characteristics of the mortars, were evaluated using X-ray diffraction (XRD), Fourier transform.
infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy dispersive X-ray
(EDX) analysis after a curing period of 28 days. The study also evaluated the photochromic (color
coordinates) and optical responses (absorbance values) of cement and polymeric samples exposed to control and urban-industrial environments for 28 and 180 days, respectively. The results
demonstrated that polymeric photochromic mortars (epoxy and polyester) exhibited higher compressive strength and ultrasonic pulse velocity values compared to photochromic cement mortars. Additionally, the findings showed that polymeric photochromic mortars (epoxy and polyester) had greater absorbance values and maintained their photochromic response over time
compared to photochromic cement mortars.

INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING AND BUSINESS SCIENCES (IJAEBS), 2023

his paper presents the results of an experimental program and a nonlinear numerical investigation... more his paper presents the results of an experimental program and a nonlinear numerical investigation on the behavior of high strength steel fibers reinforced concrete deep beams under monotonic static loads. Seventeen simply supported deep beams were tested and analyzed. The mean compressive strength of concrete is 60 MPa. The specimens are divided into five groups with different structural parameters. The studied parameters are: (1) steel fiber volume fractions, (2) fibers aspect ratios, (3) shear span-to-depth ratios, (4) horizontal web reinforcement and (5) vertical web reinforcement ratios. The measured testing results are used to study the influence of steel fibers on the structural response such as: (1) the first diagonal cracking load, (2) ultimate shear capacity, (3) load-deflection curves, (4) load-steel strain relationships, (5) failure modes, and (6) crack propagation patterns. The testing results indicated that the load carrying capacity at different levels, and displacement ductility increased considerably with the increase of fiber volume and/or fiber aspect ratio. Also, inclusion of steel fibers delays the crack propagation process and reduces the deflection and crack width. Also, the results showed that the measured concrete strain profiles at critical sections are nonlinear. In this study, the tested beams were modeled using ANSYS nonlinear finite element program which was modified to include the fibers enhancement on the stress-strain relations and failure surface. The finite element predictions of the structural response show good agreement with the observed experimental behavior.

AICSGE 2019 Tenth Alexandria International Conference on Structural and Geotechnical Engineering and Management, 2019

Use of fibers in concrete jackets has been considered as an attractive method to strengthen reinf... more Use of fibers in concrete jackets has been considered as an attractive method to strengthen reinforced concrete structures. The current work showcased an experimental study on retrofit RC beams using a U-shaped jacket technique with polypropylene fibers. The considered factors were as follow, polypropylene fibers volume fractions (V f %), shear span-to-depth ratios (a/t) and the thickness of RC jacket (t j). Twelve specimens of simply-supported reinforced concrete beams were divided into three groups with different structural parameters under monotonic static load. Three specimens were tested without a jacket behaved as control beams, and subjected to the ultimate static load till failure. The other specimens were loaded at first with up to 60% of the ultimate load, then strengthened by a U-shaped RC jacket and reloaded till failure. The studied factors were polypropylene fibers volume fractions (V f %), shear span-to-depth ratios (a/t) and the thickness of RC jacket (t j).The effect of polypropylene fibers on ultimate capacity, load-deflection curves, failure modes and crack propagation patterns was studied. Strengthening using polypropylene fibers concrete jacket (PPFCJ) exhibited a significant delay in the appearance of cracks and an enhancement in the values of ultimate load of the retrofitted beams. Ideal fiber content and concrete jacket thickness were displayed at a ratio (V f = 1.50 %) and a concrete jacket thickness of 40 mm, respectively. Finally, the increase in shear span-to-depth ratios (a/t) changed the behavior of cracking from shear sudden cracks to more ductile flexural cracks. The study concluded the superiority of polypropylene fibers RC jacket in protecting and strengthening of concrete structures.

AICSGE 2019 Tenth Alexandria International Conference on Structural and Geotechnical Engineering and Management, 2019

The current work proposes a simplified approach for the computation of the dynamic deformation re... more The current work proposes a simplified approach for the computation of the dynamic deformation response as a subsequent to a sudden column removal. SDOF system was modeled for a connection between a column and a slab. The idea undertaken was to assume the slab to act as a catenary cable that was impacted by a varying impulse load during a specified time domain. In the event of a column loss scenario, the slab was assumed to begin to lose the ability to withhold the loads in bending. The paper offers a simplified way to obtain the dynamic response, as well as the displacement-based dynamic amplification factor (DAF) for the slab deformation as a subsequent of this abrupt failure of the column.

The aim of this research is to study the theoretical and experimental behavior of the short compo... more The aim of this research is to study the theoretical and experimental behavior of the short composite and that internally reinforced concrete columns subjected to eccentric compression force and biaxial bending. The parameters involved in this research are the eccentricity of the applied force and the ratio between (Mx and My) .

Computer model is achieved using Microsoft - Excel spreadsheet based on the ultimate limit state method and strain compatibility according to the Egyptian Code (ECCS 203-2001) to develop interaction diagrams for two types of columns namely, composite columns named (C)-type and internally reinforced concrete columns named (R)-type. The developed interaction diagrams using the Excel spreadsheet were verified by comparison with the (PCA-Column program) results based on American code (ACI 318-99).
The experimental program was set to test 8 specimens; 4 columns for each type, to compare the behavior of two previously mentioned types for the same external concrete dimensions and almost same area of steel inside section with nearly similar moments of inertia.

Concrete and steel strains were recorded in addition to the lateral displacement and the section capacity for each column at each load increment.
Relationships between load and both the compression and tension strains are also presented. The crack patterns, the mode of failure and the mechanical behavior are also illustrated for each column.

Finally, the average ratio of the ultimate load level (R) and experimental failure load of internally reinforced columns (R-type) and composite (C-type) is about (85%), in addition to the similarity of the concrete compression strain, lateral deflection and pattern of failure of two column types, which is a good correlation between (R-type) and (C-type) columns.

Engineering Research Journal - Benha University Faculty of Engineering at Shoubra, 2015

This paper presents an experimental investigation on high strength steel fiber reinforced concret... more This paper presents an experimental investigation on high strength steel fiber reinforced concrete (HSSFRC) deep beams behavior under monotonic static loads. Eleven simply-supported deep beams were tested and divided into three groups with different structural parameters. The studied factors were steel fiber volume fractions (Vf), fibers aspect ratios (lf/df)
and shear span-to-depth ratios (a/d). The mean compressive strength of concrete is 60 MPa. The main objectives were to study the effect of fibers inclusion on response characteristics such as the shear carrying capacity, load-deflection curves, load-steel strain relationships, concrete surface strains, and failure modes. The testing results indicated that (a/d) ratio has a significant effect on the behavior of deep beams. Also, load carrying capacity, stiffness and strain ductility increase considerably with the increase of (Vf) or (lf/df) ratio.

Inder Science Publisher, 2014

Experimental investigation of reinforced concrete composite columns behaviour was conducted. Eigh... more Experimental investigation of reinforced concrete composite columns behaviour was conducted. Eight rectangular reinforced concrete columns with different parameters were tested under axial loads and biaxial bending. Four columns were internally reinforced with I-section structural steel and the other four were heavily reinforced with reinforcement bars with an equivalent area to the I-section. The variables considered in the study were: 1 the eccentricity of the applied force 2 the ratio of M x and M y. The main goal of this research was to compare the behaviour of the two groups. The results of the tests indicated that the experimental loads for internally reinforced columns were about 82% of that for the composite columns. A computer program was developed based on the ACI provisions to calculate the theoretical capacity of the tested columns. All the experimental failure loads were greater than the predicted theoretical values by an average value of 84%.

Thesis Chapters by Ahmed Abdelaziz Elbarbary

Ph. D. Thesis, 2015

Deep beams are structural members used in high rise buildings as transfer girders, in foundation ... more Deep beams are structural members used in high rise buildings as transfer girders, in foundation as walls and as pile caps, and in water structures as wall of tanks. In the present work, the effect of steel fibers inclusion on the behavior of High Strength Steel Fibers Reinforced Concrete (HSSFRC) deep beams is studied under monotonic static loading. An extensive experimental program was performed to study the different fibers contents (Vf), fibers aspect ratios (lf/df), shear span-to-depth ratios (a/d) and web horizontal and vertical reinforcement ratios (Ah), (Av) up to failure. Finally, the test results are compared to the predictions of nonlinear finite element (FE) analysis using the ANSYS 10 program. A Modified Strut-and-Tie Model (MSTM) is presented as powerful tool for the analysis and design of (HSSFRC) deep beams. The results of MSTM are compared with experimental results and predictions of traditional STM.

researchgate.net, 2015

High strength Steel Fiber Reinforced Concrete (HSSFRC) is a composite material consisting of rand... more High strength Steel Fiber Reinforced Concrete (HSSFRC) is a composite material consisting of randomly distributed discrete steel fibers embedded in a high strength concrete matrix. For reinforced concrete structural members, HSSFRC is used with conventional reinforcing steel bars. First, the mechanical properties of HSSFRC composite are more difficult define depending upon the particular conditions of steel fibers properties, concrete matrix qualities, mixing, curing, rate of loading and environmental influences. The knowledge of the stress-strain behavior in compression and tension is frequently required for structural analysis and design. This chapter presents the literature survey of previous studies on the experimental behavior and theoretical studies of fibrous concrete in general and HSSFRC for different structural members deep beams in particular. Then, the experimentally observed mechanical properties of fibrous and non-fibrous concretes are reviewed. Several experimental studies found in the literature for deep beams are investigated. Finally, the current codes provisions such as Construction Industry Research and Information Association in London CIRIA, American Code ACI and Egyptian Code ECCS are discussed with regard to the flexural and shear design and detailing of deep beams. The final part addresses the advanced analytical studies; Strut-and-Tie and Finite element models, with the different constitutive theories for steel fiber concrete. 2.2 Behavior of Non-Fibrous and Fibrous Concrete Several experimental investigations have been worked out to identify the mechanical properties of normal strength and high strength reinforced concrete with or without fibers under different loading conditions. A comprehensive sate of the art can be found in [7-9] for non-fibrous reinforced concrete, and in [16-20] for fibrous reinforced concrete.

Behavior of Bi-axially loaded short composite and internally RC columns, 2006

The aim of this research is to study the theoretical and experimental behavior of the short compo... more The aim of this research is to study the theoretical and experimental behavior of the short composite and that internally reinforced concrete columns subjected to eccentric compression force and biaxial bending. The parameters involved in this research are the eccentricity of the applied force and the ratio between (Mx and My) . Computer model is achieved using Microsoft - Excel spreadsheet based on the ultimate limit state method and strain compatibility according to the Egyptian Code (ECCS 203-2001) to develop interaction diagrams for two types of columns namely, composite columns named (C)-type and internally reinforced concrete columns named (R)-type. The developed interaction diagrams using the Excel spreadsheet were verified by comparison with the (PCA-Column program) results based on American code (ACI 318-99). The experimental program was set to test 8 specimens; 4 columns for each type, to compare the behavior of two previously mentioned types for the same external concrete dimensions and almost same area of steel inside section with nearly similar moments of inertia. Concrete and steel strains were recorded in addition to the lateral displacement and the section capacity for each column at each load increment. Relationships between load and both the compression and tension strains are also presented. The crack patterns, the mode of failure and the mechanical behavior are also illustrated for each column. Finally, the average ratio of the ultimate load level (R) and experimental failure load of internally reinforced columns (R-type) and composite (C-type) is about (85%), in addition to the similarity of the concrete compression strain, lateral deflection and pattern of failure of two column types, which is a good correlation between (R-type) and (C-type) columns.

Curved and Layered Structures, 2024

The main idea of this research is to manufacture plastic fibers (PFs) by recycling harmful plasti... more The main idea of this research is to manufacture plastic fibers (PFs) by recycling harmful plastic waste after washing it with water and drying it, then cutting it into strips and immersing them in liquid nitrogen, using a rotating iron basin mixer containing iron balls that touch these strips, producing fibers that are woven later to be similar to carbon-fiber-reinforced polymer (CFRP). This process is the first in the world, and the cost of manufacturing these fibers is very low compared to the cost of producing CFRP, as the cost of producing these fibers is 25 times less than the cost of producing CFRP. All the physical, chemical, and mechanical properties of the manufactured PFs were investigated and compared with the properties of CFRP. In this research, it was found that the manufactured PFs have properties similar to the properties of CFRP. The experimental work consists of casting five reinforced concrete beams with a cross-section of 125 mm × 200 mm and a length of 1,200 mm. They were divided into two groups, each group containing two beams, one of which was reinforced by CFRP, and the other was repaired by CFRP. The second group also contained two beams, one of which was reinforced by PF, and the other was repaired by PF, while the fifth beam was a control beam. From the experimental results, a significant increase in the ultimate load of the beams reinforced by PF or CFRP ranged between 45.45 and 51%, respectively. This is due to the role of manufactured PFs and CFRP in restricting the width of cracks in the bending zone of reinforced or repaired concrete beams. Also, there was a change in the type of failure when changing the type of fiber, where the failure was ductile and gradual in the beams reinforced or repaired with manufactured PFs, unlike what was in the beams reinforced or repaired by CFRP, where the failure was brittle and sudden.

American Journal of Engineering Research, 2024

The negative consequences that buildings and structures may have on the environment include water... more The negative consequences that buildings and structures may have on the environment include water on energy consumption. Since the GPSS Green Pyramid Scoring System in Egypt not fully address the five pollution, energy consumption, waste generation during the construction period, and carbon dioxide gas emissions.

INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING AND BUSINESS SCIENCES (IJAEBS), 2023

A modified Strut-and-Tie model (MSTM) was developed for fibrous deep beams to include the contrib... more A modified Strut-and-Tie model (MSTM) was developed for fibrous deep beams to include the contribution of steel fibers in the internal resistance for compression and tension. The proposed (MSTM) calculates the ultimate loads for several experimental results. The ratio between experimental results and MSTM predictions (Pu(EXP) /Pu(MSTM)) for 79 specimens is 1.20%. The results of the Strut-and-Tie for the American Code (Pu(ACI)) and Egyptian Code (Pu(ECCS)) are more conservative. The inclusion of steel fibers increases the shear capacity of deep beams by 13% and 19% respectively in compassion with ACI Code and the Egyptian Code. The ratio for (Pu(EXP) /Pu(ACI)) and (PuEXP /Pu(ECCS)) are 1.36 and 1.43, respectively. The predictions of (MSTM) are consistent, accurate, and have a great degree of validation for (HSSFRC) deep beams with different geometrical properties, concrete compressive strength, fibers, main and web steel ratios.

Journal of University of Babylon for Engineering Sciences (JUBES), 2023

Humans need to keep on the clean environment in order to refine suitable life for the next genera... more Humans need to keep on the clean environment in order to refine suitable life for the next generators. Where, the different industries formed by human, cause the environmental pollution by landfill with wastes produced from it and cause the consumption of fresh raw materials. One of these industries, is gypsum plaster industry. Where, a large amount of gypsum plaster waste is produced from different fields that use the gypsum plaster. Therefore, it is necessary to work on reduction of these wastes by reusing or recycling them with the least costs and procedures. This study aims to review the ways used to reduce gypsum waste amount and to figure ant the best among them. It can be concluded that the best ways to reduce the gypsum waste amount are by recycling it with the least costs or reusing it without any additional procedures.

Journal of Building Engineering, 2023

he utilization of photochromic cement and photochromic polymeric (epoxy and polyester) mortars in... more he utilization of photochromic cement and photochromic polymeric (epoxy and polyester) mortars in building applications is explored in this study. In order to achieve the objective, photochromic cement, epoxy, and polyester mortars were fabricated, and their performances were
comparatively evaluated. The physical and mechanical properties, including water absorption,
compressive strength, and ultrasonic pulse velocity, as well as the phase and microstructural
characteristics of the mortars, were evaluated using X-ray diffraction (XRD), Fourier transform.
infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy dispersive X-ray
(EDX) analysis after a curing period of 28 days. The study also evaluated the photochromic (color
coordinates) and optical responses (absorbance values) of cement and polymeric samples exposed to control and urban-industrial environments for 28 and 180 days, respectively. The results
demonstrated that polymeric photochromic mortars (epoxy and polyester) exhibited higher compressive strength and ultrasonic pulse velocity values compared to photochromic cement mortars. Additionally, the findings showed that polymeric photochromic mortars (epoxy and polyester) had greater absorbance values and maintained their photochromic response over time
compared to photochromic cement mortars.

INTERNATIONAL JOURNAL OF ADVANCED ENGINEERING AND BUSINESS SCIENCES (IJAEBS), 2023

his paper presents the results of an experimental program and a nonlinear numerical investigation... more his paper presents the results of an experimental program and a nonlinear numerical investigation on the behavior of high strength steel fibers reinforced concrete deep beams under monotonic static loads. Seventeen simply supported deep beams were tested and analyzed. The mean compressive strength of concrete is 60 MPa. The specimens are divided into five groups with different structural parameters. The studied parameters are: (1) steel fiber volume fractions, (2) fibers aspect ratios, (3) shear span-to-depth ratios, (4) horizontal web reinforcement and (5) vertical web reinforcement ratios. The measured testing results are used to study the influence of steel fibers on the structural response such as: (1) the first diagonal cracking load, (2) ultimate shear capacity, (3) load-deflection curves, (4) load-steel strain relationships, (5) failure modes, and (6) crack propagation patterns. The testing results indicated that the load carrying capacity at different levels, and displacement ductility increased considerably with the increase of fiber volume and/or fiber aspect ratio. Also, inclusion of steel fibers delays the crack propagation process and reduces the deflection and crack width. Also, the results showed that the measured concrete strain profiles at critical sections are nonlinear. In this study, the tested beams were modeled using ANSYS nonlinear finite element program which was modified to include the fibers enhancement on the stress-strain relations and failure surface. The finite element predictions of the structural response show good agreement with the observed experimental behavior.

AICSGE 2019 Tenth Alexandria International Conference on Structural and Geotechnical Engineering and Management, 2019

Use of fibers in concrete jackets has been considered as an attractive method to strengthen reinf... more Use of fibers in concrete jackets has been considered as an attractive method to strengthen reinforced concrete structures. The current work showcased an experimental study on retrofit RC beams using a U-shaped jacket technique with polypropylene fibers. The considered factors were as follow, polypropylene fibers volume fractions (V f %), shear span-to-depth ratios (a/t) and the thickness of RC jacket (t j). Twelve specimens of simply-supported reinforced concrete beams were divided into three groups with different structural parameters under monotonic static load. Three specimens were tested without a jacket behaved as control beams, and subjected to the ultimate static load till failure. The other specimens were loaded at first with up to 60% of the ultimate load, then strengthened by a U-shaped RC jacket and reloaded till failure. The studied factors were polypropylene fibers volume fractions (V f %), shear span-to-depth ratios (a/t) and the thickness of RC jacket (t j).The effect of polypropylene fibers on ultimate capacity, load-deflection curves, failure modes and crack propagation patterns was studied. Strengthening using polypropylene fibers concrete jacket (PPFCJ) exhibited a significant delay in the appearance of cracks and an enhancement in the values of ultimate load of the retrofitted beams. Ideal fiber content and concrete jacket thickness were displayed at a ratio (V f = 1.50 %) and a concrete jacket thickness of 40 mm, respectively. Finally, the increase in shear span-to-depth ratios (a/t) changed the behavior of cracking from shear sudden cracks to more ductile flexural cracks. The study concluded the superiority of polypropylene fibers RC jacket in protecting and strengthening of concrete structures.

AICSGE 2019 Tenth Alexandria International Conference on Structural and Geotechnical Engineering and Management, 2019

The current work proposes a simplified approach for the computation of the dynamic deformation re... more The current work proposes a simplified approach for the computation of the dynamic deformation response as a subsequent to a sudden column removal. SDOF system was modeled for a connection between a column and a slab. The idea undertaken was to assume the slab to act as a catenary cable that was impacted by a varying impulse load during a specified time domain. In the event of a column loss scenario, the slab was assumed to begin to lose the ability to withhold the loads in bending. The paper offers a simplified way to obtain the dynamic response, as well as the displacement-based dynamic amplification factor (DAF) for the slab deformation as a subsequent of this abrupt failure of the column.

The aim of this research is to study the theoretical and experimental behavior of the short compo... more The aim of this research is to study the theoretical and experimental behavior of the short composite and that internally reinforced concrete columns subjected to eccentric compression force and biaxial bending. The parameters involved in this research are the eccentricity of the applied force and the ratio between (Mx and My) .

Computer model is achieved using Microsoft - Excel spreadsheet based on the ultimate limit state method and strain compatibility according to the Egyptian Code (ECCS 203-2001) to develop interaction diagrams for two types of columns namely, composite columns named (C)-type and internally reinforced concrete columns named (R)-type. The developed interaction diagrams using the Excel spreadsheet were verified by comparison with the (PCA-Column program) results based on American code (ACI 318-99).
The experimental program was set to test 8 specimens; 4 columns for each type, to compare the behavior of two previously mentioned types for the same external concrete dimensions and almost same area of steel inside section with nearly similar moments of inertia.

Concrete and steel strains were recorded in addition to the lateral displacement and the section capacity for each column at each load increment.
Relationships between load and both the compression and tension strains are also presented. The crack patterns, the mode of failure and the mechanical behavior are also illustrated for each column.

Finally, the average ratio of the ultimate load level (R) and experimental failure load of internally reinforced columns (R-type) and composite (C-type) is about (85%), in addition to the similarity of the concrete compression strain, lateral deflection and pattern of failure of two column types, which is a good correlation between (R-type) and (C-type) columns.

Engineering Research Journal - Benha University Faculty of Engineering at Shoubra, 2015

This paper presents an experimental investigation on high strength steel fiber reinforced concret... more This paper presents an experimental investigation on high strength steel fiber reinforced concrete (HSSFRC) deep beams behavior under monotonic static loads. Eleven simply-supported deep beams were tested and divided into three groups with different structural parameters. The studied factors were steel fiber volume fractions (Vf), fibers aspect ratios (lf/df)
and shear span-to-depth ratios (a/d). The mean compressive strength of concrete is 60 MPa. The main objectives were to study the effect of fibers inclusion on response characteristics such as the shear carrying capacity, load-deflection curves, load-steel strain relationships, concrete surface strains, and failure modes. The testing results indicated that (a/d) ratio has a significant effect on the behavior of deep beams. Also, load carrying capacity, stiffness and strain ductility increase considerably with the increase of (Vf) or (lf/df) ratio.

Inder Science Publisher, 2014

Experimental investigation of reinforced concrete composite columns behaviour was conducted. Eigh... more Experimental investigation of reinforced concrete composite columns behaviour was conducted. Eight rectangular reinforced concrete columns with different parameters were tested under axial loads and biaxial bending. Four columns were internally reinforced with I-section structural steel and the other four were heavily reinforced with reinforcement bars with an equivalent area to the I-section. The variables considered in the study were: 1 the eccentricity of the applied force 2 the ratio of M x and M y. The main goal of this research was to compare the behaviour of the two groups. The results of the tests indicated that the experimental loads for internally reinforced columns were about 82% of that for the composite columns. A computer program was developed based on the ACI provisions to calculate the theoretical capacity of the tested columns. All the experimental failure loads were greater than the predicted theoretical values by an average value of 84%.

Ph. D. Thesis, 2015

Deep beams are structural members used in high rise buildings as transfer girders, in foundation ... more Deep beams are structural members used in high rise buildings as transfer girders, in foundation as walls and as pile caps, and in water structures as wall of tanks. In the present work, the effect of steel fibers inclusion on the behavior of High Strength Steel Fibers Reinforced Concrete (HSSFRC) deep beams is studied under monotonic static loading. An extensive experimental program was performed to study the different fibers contents (Vf), fibers aspect ratios (lf/df), shear span-to-depth ratios (a/d) and web horizontal and vertical reinforcement ratios (Ah), (Av) up to failure. Finally, the test results are compared to the predictions of nonlinear finite element (FE) analysis using the ANSYS 10 program. A Modified Strut-and-Tie Model (MSTM) is presented as powerful tool for the analysis and design of (HSSFRC) deep beams. The results of MSTM are compared with experimental results and predictions of traditional STM.

researchgate.net, 2015

High strength Steel Fiber Reinforced Concrete (HSSFRC) is a composite material consisting of rand... more High strength Steel Fiber Reinforced Concrete (HSSFRC) is a composite material consisting of randomly distributed discrete steel fibers embedded in a high strength concrete matrix. For reinforced concrete structural members, HSSFRC is used with conventional reinforcing steel bars. First, the mechanical properties of HSSFRC composite are more difficult define depending upon the particular conditions of steel fibers properties, concrete matrix qualities, mixing, curing, rate of loading and environmental influences. The knowledge of the stress-strain behavior in compression and tension is frequently required for structural analysis and design. This chapter presents the literature survey of previous studies on the experimental behavior and theoretical studies of fibrous concrete in general and HSSFRC for different structural members deep beams in particular. Then, the experimentally observed mechanical properties of fibrous and non-fibrous concretes are reviewed. Several experimental studies found in the literature for deep beams are investigated. Finally, the current codes provisions such as Construction Industry Research and Information Association in London CIRIA, American Code ACI and Egyptian Code ECCS are discussed with regard to the flexural and shear design and detailing of deep beams. The final part addresses the advanced analytical studies; Strut-and-Tie and Finite element models, with the different constitutive theories for steel fiber concrete. 2.2 Behavior of Non-Fibrous and Fibrous Concrete Several experimental investigations have been worked out to identify the mechanical properties of normal strength and high strength reinforced concrete with or without fibers under different loading conditions. A comprehensive sate of the art can be found in [7-9] for non-fibrous reinforced concrete, and in [16-20] for fibrous reinforced concrete.

Behavior of Bi-axially loaded short composite and internally RC columns, 2006

The aim of this research is to study the theoretical and experimental behavior of the short compo... more The aim of this research is to study the theoretical and experimental behavior of the short composite and that internally reinforced concrete columns subjected to eccentric compression force and biaxial bending. The parameters involved in this research are the eccentricity of the applied force and the ratio between (Mx and My) . Computer model is achieved using Microsoft - Excel spreadsheet based on the ultimate limit state method and strain compatibility according to the Egyptian Code (ECCS 203-2001) to develop interaction diagrams for two types of columns namely, composite columns named (C)-type and internally reinforced concrete columns named (R)-type. The developed interaction diagrams using the Excel spreadsheet were verified by comparison with the (PCA-Column program) results based on American code (ACI 318-99). The experimental program was set to test 8 specimens; 4 columns for each type, to compare the behavior of two previously mentioned types for the same external concrete dimensions and almost same area of steel inside section with nearly similar moments of inertia. Concrete and steel strains were recorded in addition to the lateral displacement and the section capacity for each column at each load increment. Relationships between load and both the compression and tension strains are also presented. The crack patterns, the mode of failure and the mechanical behavior are also illustrated for each column. Finally, the average ratio of the ultimate load level (R) and experimental failure load of internally reinforced columns (R-type) and composite (C-type) is about (85%), in addition to the similarity of the concrete compression strain, lateral deflection and pattern of failure of two column types, which is a good correlation between (R-type) and (C-type) columns.