Dr. ElSafty is a “Distinguished Professor” at the University of North Florida (UNF), where he helped advance the civil engineering undergraduate program and established the new graduate program in 2005. Prior to joining UNF, he was the founding faculty of the Civil Engineering Department at Florida State University, at Panama City campus (2003-2005). ElSafty earned his PhD from North Carolina State University (NCSU) in 1994, and his MBA from UNF in 2021, and has had extensive industrial and academic experiences for over 30 years. ElSafty is a “Fulbright Scholar”, a “Fulbright Specialist”, the Chair of the “Academic Council” for the “Precast/Prestressed Concrete Institute PCI-Foundation” and a member of its “Board of Trustees”. He’s the recipient of a National Award “The Educator of The Year Award” by the PCI in 2015, in addition to other awards in teaching, research, leadership, and service. ElSafty earned a national grant to establish the 1st Engineering Design Studio for the PCI-Foundation in the US (2009-2015). Through collaboration with researchers from 8 different universities, ElSafty has secured $2.5 million in research funds and published 104 journal and conference papers. ElSafty has led faculty groups on international academic visits to Turkey, Morocco, and Egypt to establish and maintain research initiatives and exchange programs. ElSafty has led teams of students to win regional and national competitions and has led student groups on international TLO
High-density polyethylene (HDPE) pipe is one of the materials of interest for use in road drainag... more High-density polyethylene (HDPE) pipe is one of the materials of interest for use in road drainage systems. The combination of ultraviolet (UV) light, temperature, and moisture can produce weak spots and lead to pipe degradation during the storage, installation, and repair process. The objective of this study was to evaluate changes in the chemical, morphological structure, and thermomechanical properties of recycled and virgin pipes under UV exposure. Laboratory accelerated aging tests were conducted by exposing pipes to UV for 3600 hours with an irradiance of 0.89 W/(m2 nm) at a wavelength of 340 nm. A cycle of 12 hours—comprised of 8 hours of UV radiation at 60°C and 4 hours of no UV radiation at 50°C corresponding to no water condensation—was performed to condition the specimens. HDPE specimens were taken out after 3600 hours and analyzed with FTIR (Fourier-transform infrared spectroscopy), SEM (scanning electron microscopy), DSC (differential scanning calorimetry), oxidative-in...
One of the biggest problems affecting bridges is the transverse cracking and deterioration of con... more One of the biggest problems affecting bridges is the transverse cracking and deterioration of concrete bridge decks. The causes of early age cracking are primarily attributed to plastic shrinkage, temperature effects, autogenous shrinkage, and drying shrinkage. The cracks can be influenced by material characteristics, casting sequence, formwork, climate conditions, geometry, vehicle loading, and time-dependent effects. The cracking of bridge decks not only creates unsightly aesthetic condition but also reduces deck durability. That can lead to corrosion problems of deck steel reinforcement and supporting steel girders (steel box girders and built-up steel girders). The lab testing, experimental field testing, and analytical study investigate the transverse cracking, especially early age cracking of bridge decks, and how to mitigate them. This research identifies suitable sealing materials for deck cracks showing their ability to span cracks of various widths and achieving performance criteria such as penetration depth, bond strength to crack walls, elongation, viscosity, penetration, and suitability of the type of sealant. Sealant performance was investigated by testing core samples to determine the depth of sealant penetration, bond, and tensile strength. Sealer samples were tested to verify their strength, modulus of elasticity, and elongation. A finite element model was developed to investigate the factors affecting tensile stresses and crack tendency. It also checks the live-load deflection limit, which is an important factor in bridge deck cracking. An Excel spreadsheet was also developed to predict the deck cracking accounting for shrinkage, thermal effect, creep, concrete mix design, deck restraint, loading, and environmental effects.
One of the biggest problems affecting bridges is the transverse cracking and deterioration of con... more One of the biggest problems affecting bridges is the transverse cracking and deterioration of concrete bridge decks. The causes of early age cracking are primarily attributed to plastic shrinkage, temperature effects, autogenous shrinkage, and drying shrinkage. The cracks can be influenced by material characteristics, casting sequence, formwork, climate conditions, geometry, vehicle loading, and time-dependent effects. The cracking of bridge decks not only creates unsightly aesthetic condition but also reduces deck durability. That can lead to corrosion problems of deck steel reinforcement and supporting steel girders (steel box girders and built-up steel girders). The lab testing, experimental field testing, and analytical study investigate the transverse cracking, especially early age cracking of bridge decks, and how to mitigate them. This research identifies suitable sealing materials for deck cracks showing their ability to span cracks of various widths and achieving performance criteria such as penetration depth, bond strength to crack walls, elongation, viscosity, penetration, and suitability of the type of sealant. Sealant performance was investigated by testing core samples to determine the depth of sealant penetration, bond, and tensile strength. Sealer samples were tested to verify their strength, modulus of elasticity, and elongation. A finite element model was developed to investigate the factors affecting tensile stresses and crack tendency. It also checks the live-load deflection limit, which is an important factor in bridge deck cracking. An Excel spreadsheet was also developed to predict the deck cracking accounting for shrinkage, thermal effect, creep, concrete mix design, deck restraint, loading, and environmental effects.
Current Situation A common method of government contracting is seeking the lowest bid that meets ... more Current Situation A common method of government contracting is seeking the lowest bid that meets project specifications. While this assures that money is saved upfront, it may not ensure other project values, such as delivery time, ability to address unforeseen situations, and durability of the contract’s products. Alternative contracting methods based on performance measured by these values were first used by the Florida Department of Transportation (FDOT) in 2000. Since that time, improvements based on experience have led to more widespread use. While managers have confidence in the effectiveness of AMC, it has never been formally studied.
Abstract: Repair using Carbon Fiber Reinforced Polymers (CFRP) prepreg fabric/sheets for damaged ... more Abstract: Repair using Carbon Fiber Reinforced Polymers (CFRP) prepreg fabric/sheets for damaged reinforced concrete has been investigated in this study. To simulate vehicle impact, damage was induced to ten reinforced concrete (RC) beams of (5” x 10” x 8 ft). ...
PDFTech ReportBDV34-977-01ConstructionBridge decksLoadsConcrete bridgesUnited StatesFloridaFlorid... more PDFTech ReportBDV34-977-01ConstructionBridge decksLoadsConcrete bridgesUnited StatesFloridaFlorida. Dept. of Transportation. Research CenterElsafty, AdelFlorida. Dept. of Transportation. Research CenterUniversity of North FloridaPotter, WilliamUS Transportation CollectionThe most common method used to design and analyze bridge decks, termed the traditionalmethod, treats a deck slab as if it were made of strips supported by inflexible girders. Analternative \ue2\u20ac\u201c the empirical method \ue2\u20ac\u201c treats the deck slab as a unit that resists load primarilythrough internal arching action. The mechanics of the empirical method are more complex, butthe design process is simpler, and it offers advantages in economy and constructability \ue2\u20ac\u201c e.g.,the empirical method requires much less internal reinforcement. A few states allow the empiricalmethod; however, in Florida, this method awaitsverification testing for phased construction andwidening situations before it can be allowed in thedesign guidelines.University of North Florida researchers tested theefficacy of the empirical method for bridge deckdesign, in a widening situation using a full-scalebridge deck and support structures
Deteriorated deck joints and cracks in girders pose a persistent performance and maintenance prob... more Deteriorated deck joints and cracks in girders pose a persistent performance and maintenance problem for our bridges. Using jointless bridge decks reduces direct and indirect costs associated with bridge maintenance and repair. Also, using FRP in girders’ flexure strengthening proved to be effective. In this research, an experimental testing was conducted on five girders to study the effect of CFRP bonded to the tension fibers in flexure and sides in shear. This paper also presents an approach to investigate the behavior of jointless bridge deck systems using a nonlinear finite element analysis for bridges subjected to instantaneous and time-dependent effects. The study covers key parameters such as support configurations, time-dependent effects, link slab stiffness, and debonded length. Analytical results of mode of deformation, strains, and deflections were compared with experimental testing. The study suggested that the use of debonded link slab and CFRP laminates in girder repair can be effective in extending the service life of new or repaired bridges. BACKGROUND Concern about the deterioration of bridges has prompted research efforts to find effective and economical rehabilitation systems. Extensive research has shown that externally bonded CFRP laminates improve both short term [Nanni 1997, Okeil et al. 2001] as well as long term behavior of concrete girders. The technique of externally bonding carbon fiber reinforced polymer (CFRP) laminates to reinforced concrete girders is becoming more established as an alternative to traditional structural rehabilitation methods. CFRP laminates has proven effective for both strengthening and stiffening reinforced concrete (RC) bridge girders. CFRP provide extra tensile resistance and are attached to the bottom surface or wrapped around the stem of RC beams using epoxy adhesives. Bonding FRP reinforcement to the tension face of a concrete flexural member with fibers oriented along the length of the member will provide an increase in flexural strength. Increases in overall flexural strength from 10 to 160% have been documented [Sharif et al. 1994]. Possible failure mechanisms are crushing of the concrete in compression before yielding of the reinforcing steel; yielding of the steel in tension followed by rupture of the FRP laminate; yielding of the steel in tension followed by concrete crushing; shear/tension delamination of the concrete cover (cover delamination); and debonding of the FRP from the concrete substrate Another retrofit alternative using continuous decks was studies. Several methods for the analysis of jointless deck systems were proposed [El-Safty 1994, Gastal 1987]. The loaddeflection response of a jointless bridge deck was investigated [El-Safty 1994] using a finite
2020PDFTech ReportElsafty, AdelHsuan, Yick (Grace)University of North FloridaFlorida. Department ... more 2020PDFTech ReportElsafty, AdelHsuan, Yick (Grace)University of North FloridaFlorida. Department of TransportationUniversity of North FloridaFloridaUnited StatesAccelerated testsCoatingsLaboratory testsRetroreflectivitySunlightTraffic control devicesWeatheringUltraviolet radiationLaboratory Accelerated TestSunlight DegradationOutdoor ExposureBE717Final Report, February 2019 - February 2020This project was undertaken to identify the appropriate accelerated laboratory testing procedures and conditions for predicting weathering deterioration of coating materials for steel structures and retroreflective sign sheeting materials for traffic control. The current standard test methods specified by state transportation departments, FHWA, and manufacturers were reviewed. The effects of test parameters, including irradiance, temperature, moisture, chloride ion concentration, and exposure duration, were discussed. The correlation of various laboratory accelerated test methods with outdoor testing were evaluated and analyzed. The acceleration factors of different accelerated laboratory tests were calculated using the corresponding published test data. Test protocols for the coating materials and sign sheeting materials were recommended. For the coating materials, test conditions of ASTM D5894 were modified by increasing the UV irradiance, temperature, chloride ion concentration, and test duration to shorten the testing time to 10% of the outdoor exposure. For the sign sheeting materials, irradiance levels during xenon light-on periods of the test procedure according to ASTM D7869 were increased to accomplish the testing time of 16% of the outdoor testing duration.112
Construction engineering companies usually provide a variety of services. To be competitive, comp... more Construction engineering companies usually provide a variety of services. To be competitive, companies have to organize their operations strategically based on market demands within the limitations of their own resources. Optimization of these resources is of vital importance for these companies. Historically, decisions on resource allocations to various construction market segments were made exclusively based on intuitive judgment. In previous literature, the proposed models on capital allocation place emphasis on formulating cash-flow forecasting and planning strategy on project level. However, existing technologies and established mathematical methods provide a sound base for quantitative analysis on company-level business strategy and capital allocation. This note proposes a linear programming model that can be conveniently applied by construction practitioners. The model incorporates the project cost structure and considers the business constraints such as bonding capacity and borrowing capital capac...
Abstract Marine, coastal structures, and bridges deteriorate prematurely due to corrosion. Numero... more Abstract Marine, coastal structures, and bridges deteriorate prematurely due to corrosion. Numerous failures have occurred in substructure members of these structures, such as piles, leading to ver...
High-density polyethylene (HDPE) pipe is one of the materials of interest for use in road drainag... more High-density polyethylene (HDPE) pipe is one of the materials of interest for use in road drainage systems. The combination of ultraviolet (UV) light, temperature, and moisture can produce weak spots and lead to pipe degradation during the storage, installation, and repair process. The objective of this study was to evaluate changes in the chemical, morphological structure, and thermomechanical properties of recycled and virgin pipes under UV exposure. Laboratory accelerated aging tests were conducted by exposing pipes to UV for 3600 hours with an irradiance of 0.89 W/(m2 nm) at a wavelength of 340 nm. A cycle of 12 hours—comprised of 8 hours of UV radiation at 60°C and 4 hours of no UV radiation at 50°C corresponding to no water condensation—was performed to condition the specimens. HDPE specimens were taken out after 3600 hours and analyzed with FTIR (Fourier-transform infrared spectroscopy), SEM (scanning electron microscopy), DSC (differential scanning calorimetry), oxidative-in...
One of the biggest problems affecting bridges is the transverse cracking and deterioration of con... more One of the biggest problems affecting bridges is the transverse cracking and deterioration of concrete bridge decks. The causes of early age cracking are primarily attributed to plastic shrinkage, temperature effects, autogenous shrinkage, and drying shrinkage. The cracks can be influenced by material characteristics, casting sequence, formwork, climate conditions, geometry, vehicle loading, and time-dependent effects. The cracking of bridge decks not only creates unsightly aesthetic condition but also reduces deck durability. That can lead to corrosion problems of deck steel reinforcement and supporting steel girders (steel box girders and built-up steel girders). The lab testing, experimental field testing, and analytical study investigate the transverse cracking, especially early age cracking of bridge decks, and how to mitigate them. This research identifies suitable sealing materials for deck cracks showing their ability to span cracks of various widths and achieving performance criteria such as penetration depth, bond strength to crack walls, elongation, viscosity, penetration, and suitability of the type of sealant. Sealant performance was investigated by testing core samples to determine the depth of sealant penetration, bond, and tensile strength. Sealer samples were tested to verify their strength, modulus of elasticity, and elongation. A finite element model was developed to investigate the factors affecting tensile stresses and crack tendency. It also checks the live-load deflection limit, which is an important factor in bridge deck cracking. An Excel spreadsheet was also developed to predict the deck cracking accounting for shrinkage, thermal effect, creep, concrete mix design, deck restraint, loading, and environmental effects.
One of the biggest problems affecting bridges is the transverse cracking and deterioration of con... more One of the biggest problems affecting bridges is the transverse cracking and deterioration of concrete bridge decks. The causes of early age cracking are primarily attributed to plastic shrinkage, temperature effects, autogenous shrinkage, and drying shrinkage. The cracks can be influenced by material characteristics, casting sequence, formwork, climate conditions, geometry, vehicle loading, and time-dependent effects. The cracking of bridge decks not only creates unsightly aesthetic condition but also reduces deck durability. That can lead to corrosion problems of deck steel reinforcement and supporting steel girders (steel box girders and built-up steel girders). The lab testing, experimental field testing, and analytical study investigate the transverse cracking, especially early age cracking of bridge decks, and how to mitigate them. This research identifies suitable sealing materials for deck cracks showing their ability to span cracks of various widths and achieving performance criteria such as penetration depth, bond strength to crack walls, elongation, viscosity, penetration, and suitability of the type of sealant. Sealant performance was investigated by testing core samples to determine the depth of sealant penetration, bond, and tensile strength. Sealer samples were tested to verify their strength, modulus of elasticity, and elongation. A finite element model was developed to investigate the factors affecting tensile stresses and crack tendency. It also checks the live-load deflection limit, which is an important factor in bridge deck cracking. An Excel spreadsheet was also developed to predict the deck cracking accounting for shrinkage, thermal effect, creep, concrete mix design, deck restraint, loading, and environmental effects.
Current Situation A common method of government contracting is seeking the lowest bid that meets ... more Current Situation A common method of government contracting is seeking the lowest bid that meets project specifications. While this assures that money is saved upfront, it may not ensure other project values, such as delivery time, ability to address unforeseen situations, and durability of the contract’s products. Alternative contracting methods based on performance measured by these values were first used by the Florida Department of Transportation (FDOT) in 2000. Since that time, improvements based on experience have led to more widespread use. While managers have confidence in the effectiveness of AMC, it has never been formally studied.
Abstract: Repair using Carbon Fiber Reinforced Polymers (CFRP) prepreg fabric/sheets for damaged ... more Abstract: Repair using Carbon Fiber Reinforced Polymers (CFRP) prepreg fabric/sheets for damaged reinforced concrete has been investigated in this study. To simulate vehicle impact, damage was induced to ten reinforced concrete (RC) beams of (5” x 10” x 8 ft). ...
PDFTech ReportBDV34-977-01ConstructionBridge decksLoadsConcrete bridgesUnited StatesFloridaFlorid... more PDFTech ReportBDV34-977-01ConstructionBridge decksLoadsConcrete bridgesUnited StatesFloridaFlorida. Dept. of Transportation. Research CenterElsafty, AdelFlorida. Dept. of Transportation. Research CenterUniversity of North FloridaPotter, WilliamUS Transportation CollectionThe most common method used to design and analyze bridge decks, termed the traditionalmethod, treats a deck slab as if it were made of strips supported by inflexible girders. Analternative \ue2\u20ac\u201c the empirical method \ue2\u20ac\u201c treats the deck slab as a unit that resists load primarilythrough internal arching action. The mechanics of the empirical method are more complex, butthe design process is simpler, and it offers advantages in economy and constructability \ue2\u20ac\u201c e.g.,the empirical method requires much less internal reinforcement. A few states allow the empiricalmethod; however, in Florida, this method awaitsverification testing for phased construction andwidening situations before it can be allowed in thedesign guidelines.University of North Florida researchers tested theefficacy of the empirical method for bridge deckdesign, in a widening situation using a full-scalebridge deck and support structures
Deteriorated deck joints and cracks in girders pose a persistent performance and maintenance prob... more Deteriorated deck joints and cracks in girders pose a persistent performance and maintenance problem for our bridges. Using jointless bridge decks reduces direct and indirect costs associated with bridge maintenance and repair. Also, using FRP in girders’ flexure strengthening proved to be effective. In this research, an experimental testing was conducted on five girders to study the effect of CFRP bonded to the tension fibers in flexure and sides in shear. This paper also presents an approach to investigate the behavior of jointless bridge deck systems using a nonlinear finite element analysis for bridges subjected to instantaneous and time-dependent effects. The study covers key parameters such as support configurations, time-dependent effects, link slab stiffness, and debonded length. Analytical results of mode of deformation, strains, and deflections were compared with experimental testing. The study suggested that the use of debonded link slab and CFRP laminates in girder repair can be effective in extending the service life of new or repaired bridges. BACKGROUND Concern about the deterioration of bridges has prompted research efforts to find effective and economical rehabilitation systems. Extensive research has shown that externally bonded CFRP laminates improve both short term [Nanni 1997, Okeil et al. 2001] as well as long term behavior of concrete girders. The technique of externally bonding carbon fiber reinforced polymer (CFRP) laminates to reinforced concrete girders is becoming more established as an alternative to traditional structural rehabilitation methods. CFRP laminates has proven effective for both strengthening and stiffening reinforced concrete (RC) bridge girders. CFRP provide extra tensile resistance and are attached to the bottom surface or wrapped around the stem of RC beams using epoxy adhesives. Bonding FRP reinforcement to the tension face of a concrete flexural member with fibers oriented along the length of the member will provide an increase in flexural strength. Increases in overall flexural strength from 10 to 160% have been documented [Sharif et al. 1994]. Possible failure mechanisms are crushing of the concrete in compression before yielding of the reinforcing steel; yielding of the steel in tension followed by rupture of the FRP laminate; yielding of the steel in tension followed by concrete crushing; shear/tension delamination of the concrete cover (cover delamination); and debonding of the FRP from the concrete substrate Another retrofit alternative using continuous decks was studies. Several methods for the analysis of jointless deck systems were proposed [El-Safty 1994, Gastal 1987]. The loaddeflection response of a jointless bridge deck was investigated [El-Safty 1994] using a finite
2020PDFTech ReportElsafty, AdelHsuan, Yick (Grace)University of North FloridaFlorida. Department ... more 2020PDFTech ReportElsafty, AdelHsuan, Yick (Grace)University of North FloridaFlorida. Department of TransportationUniversity of North FloridaFloridaUnited StatesAccelerated testsCoatingsLaboratory testsRetroreflectivitySunlightTraffic control devicesWeatheringUltraviolet radiationLaboratory Accelerated TestSunlight DegradationOutdoor ExposureBE717Final Report, February 2019 - February 2020This project was undertaken to identify the appropriate accelerated laboratory testing procedures and conditions for predicting weathering deterioration of coating materials for steel structures and retroreflective sign sheeting materials for traffic control. The current standard test methods specified by state transportation departments, FHWA, and manufacturers were reviewed. The effects of test parameters, including irradiance, temperature, moisture, chloride ion concentration, and exposure duration, were discussed. The correlation of various laboratory accelerated test methods with outdoor testing were evaluated and analyzed. The acceleration factors of different accelerated laboratory tests were calculated using the corresponding published test data. Test protocols for the coating materials and sign sheeting materials were recommended. For the coating materials, test conditions of ASTM D5894 were modified by increasing the UV irradiance, temperature, chloride ion concentration, and test duration to shorten the testing time to 10% of the outdoor exposure. For the sign sheeting materials, irradiance levels during xenon light-on periods of the test procedure according to ASTM D7869 were increased to accomplish the testing time of 16% of the outdoor testing duration.112
Construction engineering companies usually provide a variety of services. To be competitive, comp... more Construction engineering companies usually provide a variety of services. To be competitive, companies have to organize their operations strategically based on market demands within the limitations of their own resources. Optimization of these resources is of vital importance for these companies. Historically, decisions on resource allocations to various construction market segments were made exclusively based on intuitive judgment. In previous literature, the proposed models on capital allocation place emphasis on formulating cash-flow forecasting and planning strategy on project level. However, existing technologies and established mathematical methods provide a sound base for quantitative analysis on company-level business strategy and capital allocation. This note proposes a linear programming model that can be conveniently applied by construction practitioners. The model incorporates the project cost structure and considers the business constraints such as bonding capacity and borrowing capital capac...
Abstract Marine, coastal structures, and bridges deteriorate prematurely due to corrosion. Numero... more Abstract Marine, coastal structures, and bridges deteriorate prematurely due to corrosion. Numerous failures have occurred in substructure members of these structures, such as piles, leading to ver...
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