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Title: Analytical evaluation of marine concrete pile repairs.
Creator: Saleh, Zaher A. Abou., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: The purpose of the thesis is to determine and compare the performance characteristics of marine piles corroded by chloride diffusion and repaired by several different methods for both uncracked and cracked concrete and to determine their structural integrity. The long-term objective is the comparison of the analytical values with those from an on-going experimental evaluation. The time for chloride concentration reach the threshold value that initiates corrosion in the reinforcement has been...
Show moreThe purpose of the thesis is to determine and compare the performance characteristics of marine piles corroded by chloride diffusion and repaired by several different methods for both uncracked and cracked concrete and to determine their structural integrity. The long-term objective is the comparison of the analytical values with those from an on-going experimental evaluation. The time for chloride concentration reach the threshold value that initiates corrosion in the reinforcement has been determined by Fick's law, extended to 2-D and 3-D chloride diffusion, for (a) uncracked concrete, and (b) for cracked concrete with the Simplified Smeared Approach (SSA). The structural integrity of the concrete circular pile is compared before and alter repair, by (a) finite element modeling using ANSYS software with the maximum deflection, and (b) beam strength analysis to find the moment capacity for cracked and ultimate conditions. The overall findings indicate the adequacy of the repair procedures.
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Date Issued: 2003
PURL: http://purl.flvc.org/fcla/dt/13062
Subject Headings: Concrete piling, Reinforced concrete--Corrosion, Seawater corrosion
Format: Document (PDF)

Title: Effect of elevated temperature and fire on structural elements retrofitted by carbon fiber reinforced polymer composites.
Creator: Young, Jody David, Jr., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: This thesis presents an experimental investigation for evaluating effects of fire exposure on properties of structural elements retrofitted by carbon fiber reinforced polymers. Mechanical properties of CFRP-strengthened reinforced concrete members, protected with secondary insulation, were investigated, before and after (residual) direct fire exposure. Direct fire contact resulted in a reduction in capacity of 9-20% for CFRP-strengthened RC beams, and 15-34% for CFRP-strengthened RC columns....
Show moreThis thesis presents an experimental investigation for evaluating effects of fire exposure on properties of structural elements retrofitted by carbon fiber reinforced polymers. Mechanical properties of CFRP-strengthened reinforced concrete members, protected with secondary insulation, were investigated, before and after (residual) direct fire exposure. Direct fire contact resulted in a reduction in capacity of 9-20% for CFRP-strengthened RC beams, and 15-34% for CFRP-strengthened RC columns. Furthermore, a dimensional analysis was developed for a heat transfer relationship between full and small-scale specimens, allowing a ¼ exposure time reduction for the latter. Results from experimental investigations demonstrate benefits of employing secondary fire protection to CFRP-strengthened structures, in spite of the glass transition temperature being exceeded in the early stages of the elevated-temperature exposure. Therefore, it is suggested, that fire protection is necessary for a CFRP-strengthened structural member to retain integrity throughout the duration of the fire exposure, and upon return to ambient temperature.
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Date Issued: 2006
PURL: http://purl.flvc.org/fcla/dt/13322
Subject Headings: Buildings--Repair and reconstruction, Reinforced concrete, Fiber reinforced plastics, Fire resistant materials, Thermodynamics, Heat engineering, Concrete--Effect of temperature on
Format: Document (PDF)

$Durability and fracture toughness of fly ash concrete in the marine environment$

Title: Durability and fracture toughness of fly ash concrete in the marine environment.
Creator: Lee, Seung-Kyoung, Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This thesis presents the experimental investigation of durability and fracture toughness (K IC) of fly ash concrete in the marine environment. The findings indicate that the deterioration rate of durability parameters, such as compressive strength, weight loss, and dynamic modulus of elasticity, due to 450 wet and dry cycles exposure (the Accelerated Durability Testing), was inversely proportional to the amount of fly ash replacement. On the other hand, tensile strength properties, such as...
Show moreThis thesis presents the experimental investigation of durability and fracture toughness (K IC) of fly ash concrete in the marine environment. The findings indicate that the deterioration rate of durability parameters, such as compressive strength, weight loss, and dynamic modulus of elasticity, due to 450 wet and dry cycles exposure (the Accelerated Durability Testing), was inversely proportional to the amount of fly ash replacement. On the other hand, tensile strength properties, such as modulus of rupture and fracture toughness, were independent of fly ash replacement, but increased with the period of accelerated testing. The mean K IC values of fly ash concrete mixes showed that they are closely related to their compressive strengths and size effects. According to AE, unstable crack propagation initiated at 93-97% maximum load. With SEM observations, it was found that crystallized particles were precipitated in the void spaces due to chemical reaction between the cement paste and seawater.
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Date Issued: 1990
PURL: http://purl.flvc.org/fcla/dt/14614
Subject Headings: Fly ash, Concrete--Cracking, Fracture mechanics, Concrete--Testing
Format: Document (PDF)

Title: Computer simulation of corrosion fatigue of reinforced concrete beams in marine environment.
Creator: Ranade, Sonali S., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The effect of corrosion on the fatigue life of reinforced concrete beams is studied. Two analytical models are developed to study the chloride diffusion in concrete and the percent reduction in fatigue lives in seawater as compared to air. An initial stress equivalent to the tensile strength of concrete is induced in the rebar to simulate the corrosive nature of marine environment. The analytical values are compared with the available experimental data.
Date Issued: 1993
PURL: http://purl.flvc.org/fcla/dt/14914
Subject Headings: Concrete beams--Fatigue--Computer simulation, Reinforced concrete--Corrosion, Sea water corrosion
Format: Document (PDF)

Title: Finite element analysis of the visco-elastic behavior of a spray ice island.
Creator: Thiel, David Ted., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This thesis presents a finite element analysis of the viscoelastic (creep) behavior of a spray ice island under its own self-weight and three levels of lateral loads. Spray ice and its use as a construction material are described in the context of other natural ice forms and the ice environment of the Beaufort Sea. The analytical results indicated that creep settlement in the absence of volumetric contraction was nominal over the course of a simulated 21-day construction period and a 79-day...
Show moreThis thesis presents a finite element analysis of the viscoelastic (creep) behavior of a spray ice island under its own self-weight and three levels of lateral loads. Spray ice and its use as a construction material are described in the context of other natural ice forms and the ice environment of the Beaufort Sea. The analytical results indicated that creep settlement in the absence of volumetric contraction was nominal over the course of a simulated 21-day construction period and a 79-day service life. The effects of the applied lateral loads were very localized and did not result in any appreciable deformations in the central working area of the structure. Some evidence of shear plane development and upward passive failure of the island perimeter was observed.
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Date Issued: 1990
PURL: http://purl.flvc.org/fcla/dt/14647
Subject Headings: Ice mechanics, Offshore structures--Dynamics, Sea ice--Beaufort Sea
Format: Document (PDF)

Title: Evaluation of the structural applicability of centrally prestressed, unreinforced concrete (CPUC) columns with modified Freyssinet hinges for marine and seismic environment.
Creator: Periyaiah, Rathinam., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: An innovative concept of the Centrally Prestressed, Unreinforced Concrete (CPUC) column with modified Freyssinet hinges formulated by Paul Csagoly, to prevent rebar corrosion and additionally mitigate seismic damage, was investigated. The first phase of this work emphasized the mode of failure, ultimate strength, and ductility characteristics of the CPUC columns. As expected, CPUC columns showed adequate axial and flexural resistance as well as ductility. The ultimate strengths of most of the...
Show moreAn innovative concept of the Centrally Prestressed, Unreinforced Concrete (CPUC) column with modified Freyssinet hinges formulated by Paul Csagoly, to prevent rebar corrosion and additionally mitigate seismic damage, was investigated. The first phase of this work emphasized the mode of failure, ultimate strength, and ductility characteristics of the CPUC columns. As expected, CPUC columns showed adequate axial and flexural resistance as well as ductility. The ultimate strengths of most of the CPUC columns were about 10 to 20% higher than those of conventional ones. The second phase dealt with an energy absorbing device compatible with CPUC column to meet the occasional high ductility demand of the CPUC columns in earthquake conditions. Hinges were tested for compressive strength and moment-rotation capability. Parametric studies of the hinges were conducted for different filler materials, and width-to-height ratios. The confined filler material in the Freyssinet type hinge was found to have excellent compressive strength and moment-rotation capability. The parameters, width-to-height ratios and different filler material, had significant effect on hinge's performance.
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Date Issued: 1996
PURL: http://purl.flvc.org/fcla/dt/15253
Subject Headings: Columns, Concrete--Testing, Prestressed concrete construction--Testing, Strength of materials
Format: Document (PDF)

Title: Municipal ash/fly ash utilization for the transportation infrastructure.
Creator: Yemeniciler, Ali Nejat., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This thesis addresses municipal ash-modified and fly ash-modified concrete utilization for the transportation infrastructure. The mix design included unmodified (control) concrete (Mix A), fly ash-modified concrete (Mix B), and municipal ash-modified concrete (Mix C). The laboratory investigation was carried out through compressive, tensile, testing of the cylinders and flexural testing of concrete slabs on grade comprised of varying proportions of coal fly ash and MSW bottom ash. The load...
Show moreThis thesis addresses municipal ash-modified and fly ash-modified concrete utilization for the transportation infrastructure. The mix design included unmodified (control) concrete (Mix A), fly ash-modified concrete (Mix B), and municipal ash-modified concrete (Mix C). The laboratory investigation was carried out through compressive, tensile, testing of the cylinders and flexural testing of concrete slabs on grade comprised of varying proportions of coal fly ash and MSW bottom ash. The load-strain relationships for experimental pavements was obtained through slab testing, modeled as a two-way infinite slab on an elastic foundation. A finite element model using STAAD-III was used to predict the stresses and deflection of the slab. For comparison, a simplified analysis was also performed to obtain stresses and deflections variations of the slabs, following ACI Committee 436. Based on the results presented in this report, conclusions were drawn to evaluate the ideal mix design for municipal ash-modified and fly ash-modified concrete.
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Date Issued: 1999
PURL: http://purl.flvc.org/fcla/dt/15639
Subject Headings: Concrete slabs, Coal ash--Recycling, Fly ash--Recycling
Format: Document (PDF)

Title: Wave attenuation by rigid and flexible-membrane submerged breakwaters.
Creator: Harris, Lee Errol., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This research investigates the use of rigid and flexible-membrane submerged breakwaters for wave energy attenuation. A comprehensive review of breakwater design criteria and previous research on submerged breakwaters is included. Physical model laboratory studies conducted by the author and other researchers are investigated as a means for obtaining formulations for wave transmission coefficients. The mechanisms by which waves are attenuated and break are analyzed using video photography of...
Show moreThis research investigates the use of rigid and flexible-membrane submerged breakwaters for wave energy attenuation. A comprehensive review of breakwater design criteria and previous research on submerged breakwaters is included. Physical model laboratory studies conducted by the author and other researchers are investigated as a means for obtaining formulations for wave transmission coefficients. The mechanisms by which waves are attenuated and break are analyzed using video photography of the wave tank tests. The primary objective of this doctoral research was to determine and compare the wave attenuation of non-conventional rigid and flexible-membrane type submerged breakwaters. Physical model tests were performed using the wave tank facilities at Florida Institute of Technology located in Melbourne, Florida. Six different breakwater cross-sections used were: (1) rectangular, (2) triangular, (3) P.E.P.-$Reef\sp{TM}$, (4) single sand-filled container, (5) three stacked sand-filled containers, and (6) one single water-filled container. The first three breakwater units were rigid (or monolithic), and the last three units are flexible-membrane breakwater units. All six units tested had the same height, length (longshore), and base width (cross-shore), with different cross-sections and shapes, and were composed of different materials. A new classification scheme was developed for breakwaters and artificial reefs, based on water depth, structure height, and wave heights. The wave-structure interaction resulting in the wave breaking on the submerged breakwaters was documented, and the observations were analyzed. Wave transmission coefficients were computed for the six different breakwater models tested, and comparisons between the different models were made. Conclusions regarding the primary factors affecting the effectiveness of rigid and flexible-membrane submerged breakwaters were developed, as were recommendations for further research.
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Date Issued: 1996
PURL: http://purl.flvc.org/fcla/dt/12468
Subject Headings: Breakwaters, Water waves
Format: Document (PDF)

Title: An experimental and analytical investigation of viscoelastic pipe-soil interaction.
Creator: Ahn, Woo-Suk., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: An overview of the current issues of HDPE pipe-soil systems is followed by a comprehensive literature review addressing current specifications, design methods, and relevant research projects. The following experimental tasks are described: (i) environmental stress cracking resistance (modified AASHTO M294), (ii) creep (10,000 hour parallel plate loading at super ambient temperatures), (iii) performance of buried pipes, subjected to live loading in a soil chamber, and (iv) field monitoring....
Show moreAn overview of the current issues of HDPE pipe-soil systems is followed by a comprehensive literature review addressing current specifications, design methods, and relevant research projects. The following experimental tasks are described: (i) environmental stress cracking resistance (modified AASHTO M294), (ii) creep (10,000 hour parallel plate loading at super ambient temperatures), (iii) performance of buried pipes, subjected to live loading in a soil chamber, and (iv) field monitoring. The findings include (i) satisfactory short-term environmental stress cracking resistance, (ii) temperature-dependency of the flexural modulus, (iii) the evidence of transition between slow crack growth and rapid crack propagation due to imperfect installation, and (iv) high load carrying capacity for the properly installed pipe in uniform backfill, showing an over-deflection failure mode with top flattening. The analytical investigations are as follows: (i) Bidirectional shift-constructed master curve, based on accelerated creep test values for long-term modulus prediction that showed good agreement with the Arrhenius equation-based analysis, (ii) Development of a seven-degree Voigt-Kelvin viscoelastic model based on the bidirectional shift-constructed master curve for analytical prediction of the long-term modulus, (iii) Comparison of two-dimensional and three-dimensional harmonic FEM analyses with the measured response of pipe-soil interaction, that demonstrated the analytical predictability of the pattern of deformation and stress distribution, and (iv) Determination of axial stress distribution along the pipe in non-uniform backfill condition, evaluated by approximate analysis based on finite differencing the deflection profile obtained from the assembly of individual finite segments/sections. This overcomes the limitation of the harmonic FEM analysis for pipe-soil interaction involving non-uniform soil conditions longitudinally and/or varying soil thickness circumferentially. The findings include (i) importance of axial stress contribution at failure, (ii) top flattening failure mode due to over-deflection preceding buckling or yielding, and (iii) critical adverse effect of the non-uniform backfill condition that can lead to joint opening, localized buckling, liner tearing/debonding, or cracking. The work has "spin off" applications to the coastal and offshore environments for sewage outfalls, marine pipelines etc.
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Date Issued: 1998
PURL: http://purl.flvc.org/fcla/dt/12550
Subject Headings: Soil-structure interaction, Pipe, Plastic--Testing, Underground pipelines
Format: Document (PDF)

Title: Stress intensity factors and weight functions for surface cracks using boundary/finite element alternating methods.
Creator: Mu, Ruijia., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: In the present investigation, the boundary/finite element alternating methods are used to evaluate the stress intensity factors and weight functions for surface crack problems. For two dimensional problems, Westergaard stress functions are used to find the analytical solutions for an infinite plate with an embedded crack, subjected to crack face tractions, and the boundary element method for the numerical solution. The stress intensity factors and weight functions for an arbitrary plate with...
Show moreIn the present investigation, the boundary/finite element alternating methods are used to evaluate the stress intensity factors and weight functions for surface crack problems. For two dimensional problems, Westergaard stress functions are used to find the analytical solutions for an infinite plate with an embedded crack, subjected to crack face tractions, and the boundary element method for the numerical solution. The stress intensity factors and weight functions for an arbitrary plate with an edge crack subjected to mixed mode loads are obtained by the alternating technique. For three dimensional problems, an elliptical coordinate system and the gravity potential functions are used to derive the three dimensional analytical solutions for an infinite solid with an embedded crack. The analytical solutions are derived for the cases of shear tractions and normal tractions, separately, by assuming that the tractions are symmetric about both the major and minor axes. Superposition gives the general solutions. The analytical solutions and the finite element method, in conjunction with alternating technique, are used to evaluate the stress intensity factors for a solid with a semi-elliptical surface crack, subjected to arbitrary loads. A general approach to evaluate the weight functions for a two dimensional plate with a three dimensional semi-elliptical surface crack is formulated. Numerical examples are evaluated using the formulation developed in the present investigation. The results show good agreement with those from classical solutions. The convergence characteristics of the alternating methods are also discussed. Finally, the formulation is applied to welded plate T-joints with edge/semi-elliptical surface cracks, subjected to three point bending, to obtain stress intensity factors.
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Date Issued: 1992
PURL: http://purl.flvc.org/fcla/dt/12319
Subject Headings: Fracture mechanics, Finite element method--Data processing, Materials--Fatigue, Strains and stresses
Format: Document (PDF)

Title: Strength and permeability of fly ash-modified concrete in coastal construction.
Creator: Murti, Vasu., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Three vital factors, namely environmental protection, savings in energy, and technical benefits, make it advantageous to incorporate fly ash of controlled quality and composition in all concrete construction. The specific objective of this research was to compare the performance characteristics of fly ash-modified concrete with that of normal concrete in the coastal environment. To make this comparison, a series of tests using appropriate ASTM standards were conducted. First, the compressive...
Show moreThree vital factors, namely environmental protection, savings in energy, and technical benefits, make it advantageous to incorporate fly ash of controlled quality and composition in all concrete construction. The specific objective of this research was to compare the performance characteristics of fly ash-modified concrete with that of normal concrete in the coastal environment. To make this comparison, a series of tests using appropriate ASTM standards were conducted. First, the compressive strength development of five mixes was studied. Reinforced beam specimens were then subjected to varying periods of accelerated corrosion with sea water as electrolyte. These were tested under flexure and impact. An attempt was made to predict remaining life. Finally, permeability tests were carried out. Results indicate that fly ash increases compressive strength, improves both moment carrying capacity and impact resistance, and increases watertightness.
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Date Issued: 1989
PURL: http://purl.flvc.org/fcla/dt/14545
Subject Headings: Fly ash, Concrete--Permeability
Format: Document (PDF)

Title: Soil-geosynthetic reinforcement interaction for mechanically stabilized earth (MSE) wall systems.
Creator: Navarrete, Fernando Manuel., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The dissertation is an experimental and analytical investigation of the long term performance of mechanically stabilized earth (MSE) walls with geosynthetics, with particular focus on rational methods to enable the determination of the applicable factors for use in Load Resistance Factor Design (LRFD). An overview of current issues concerning MSE walls is followed by an extensive literature review addressing MSE walls, pullout strength, creep and creep rupture, durability and degradation,...
Show moreThe dissertation is an experimental and analytical investigation of the long term performance of mechanically stabilized earth (MSE) walls with geosynthetics, with particular focus on rational methods to enable the determination of the applicable factors for use in Load Resistance Factor Design (LRFD). An overview of current issues concerning MSE walls is followed by an extensive literature review addressing MSE walls, pullout strength, creep and creep rupture, durability and degradation, design methodology, analytical prediction, and field evaluation of MSE walls. The experimental tasks comprise: (i) creep and creep rupture, (ii) durability and degradation, (iii) small scale testing of MSE walls with a model prototype ratio of 1:5.5, and (iv) construction of prototype MSE wall and instrumentation for long-term performance. The analytical work comprises finite difference modeling using the Fast Lagrangian Analysis of Continua (FLAC) software, (i) For creep up to 10,000 hours accelerated exposure for HDPE and PET geogrids, with super-ambient temperatures and soil water conditions related to soil conditions in Florida, the significant part of creep was due to temperatures and not solution exposures, with creep rupture occurring primarily for HDPE. (ii) For durability, performance at ambient temperatures was extrapolated, based on the Arrhenius method. The variation in degradation between the different solutions was minimal, indicating hydrolysis as the main cause for PET at elevated temperatures. (iii) Two HDPE and two PET reinforcement small scale (1:5.5) MSE walls were tested, with different surcharges each for 72 hour periods. Panel movements, strains in the reinforcement, and wall settlements were measured, indicating values smaller than the predicted, mostly for the smaller surcharges due to distortion caused by scaling neglecting the gravity effect. (iv) For analysis with FLAC computer software, two correction factors "a" and "b" were applied to correct the discrepancies between the model and the test values. The PET MSE small scale wall showed more deviation because the material has a low modulus of elasticity. (v) A preliminary comparison of the small scale and the prototype MSE wall behavior indicated discrepancies due to distortion scaling related to the lack of gravity simulation.
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Date Issued: 2001
PURL: http://purl.flvc.org/fcla/dt/11968
Subject Headings: Geosynthetics, Load factor design, Retaining walls, Soil stabilization
Format: Document (PDF)

Title: STRENGTH AND DURABILITY OF FIBER AND POLYMER-MODIFIED CONCRETE FOR MARINE STRUCTURAL APPLICATIONS.
Creator: NOMIKOS, GEORGE GERASSIMOS., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This thesis presents the experimental and analytical investigation of the fiber (steel, glass and Kevlar), and latex-modified concrete structural members exposed to varying periods of marine environment. The findings indicate superior behavior of fibers in flexure (toughness) and impact. Fibers affect the compressive strength only marginally. Kevlar fibers are more stable in the marine environment compared to steel and glass. The addition of latex significantly improves the durability...
Show moreThis thesis presents the experimental and analytical investigation of the fiber (steel, glass and Kevlar), and latex-modified concrete structural members exposed to varying periods of marine environment. The findings indicate superior behavior of fibers in flexure (toughness) and impact. Fibers affect the compressive strength only marginally. Kevlar fibers are more stable in the marine environment compared to steel and glass. The addition of latex significantly improves the durability characteristics. Endochronic constitutive modeling enables realistic prediction of beam flexural behavior. The smallness of the size and number of specimens tested indicates the need for further experimentation with an increased number of members of larger dimensions.
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Date Issued: 1985
PURL: http://purl.flvc.org/fcla/dt/14258
Subject Headings: Reinforced concrete, Fiber--Environmental testing, Polymer-impregnated concrete--Environmental testing
Format: Document (PDF)

Title: SERVICEABILITY OF REINFORCED CONCRETE BEAMS SUBJECTED TO ACCELERATED CORROSION (ACOUSTIC EMISSION, DAMAGE, REMAINING STRENGTH/LIFE, TESTING).
Creator: TITUS, REJI NINAN K., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Steel reinforced concrete beams were placed in contact with seawater in a state of accelerated corrosion, for varying periods of time. Some of them were simultaneously monitored for acoustic emission and the results were analyzed to evaluate the effectiveness of acoustic emission as a non-destructive monitor of corrosion induced damage. It was shown that, in a laboratory environment, counts are good indicators of the extent of corrosion damage. A review of acoustic emission monitoring...
Show moreSteel reinforced concrete beams were placed in contact with seawater in a state of accelerated corrosion, for varying periods of time. Some of them were simultaneously monitored for acoustic emission and the results were analyzed to evaluate the effectiveness of acoustic emission as a non-destructive monitor of corrosion induced damage. It was shown that, in a laboratory environment, counts are good indicators of the extent of corrosion damage. A review of acoustic emission monitoring techniques and theoretical background is included. The concrete beams were tested for flexural strength after being corroded. Reduction in rebar section was found to have a very good correlation with da mage. An attempt was made to predict remaining life of the beams based on data obtained from the tests.
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Date Issued: 1986
PURL: http://purl.flvc.org/fcla/dt/14310
Subject Headings: Reinforced concrete--Corrosion
Format: Document (PDF)

Title: Ultimate load, creep, shrinkage, and reliability studies of a precast single cell segmental bridge with external post-tensioning.
Creator: Murugesh, Ganapathy., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: This dissertation is a study of a 1:3.5 scale model of an externally post-tensioned single cell segmental bridge model of the Long Key bridge. The behavior of the bridge system was evaluated in terms of deflections, strains, joint openings, etc. under static and ultimate load conditions. The precast segmental bridge was cast, assembled, and tested at the Department of Ocean Engineering, Florida Atlantic University for AASHTO HS20-44 truck loadings at typical locations. The study addressed the...
Show moreThis dissertation is a study of a 1:3.5 scale model of an externally post-tensioned single cell segmental bridge model of the Long Key bridge. The behavior of the bridge system was evaluated in terms of deflections, strains, joint openings, etc. under static and ultimate load conditions. The precast segmental bridge was cast, assembled, and tested at the Department of Ocean Engineering, Florida Atlantic University for AASHTO HS20-44 truck loadings at typical locations. The study addressed the joint opening behavior and the response of external tendons during service and ultimate load levels. The analytical nonlinear behavior of the bridge upto the ultimate load level has been predicted using a finite element software PCFRAME developed at University of California, Berkeley. Creep and shrinkage strains were predicted using computer program CRACK developed at University of Calgary, Canada. Creep and shrinkage coefficients evaluated from short term tests, were used in predicting the long term behavior. A method for reliability analysis of post-tensioned segmental bridges has also been presented for serviceability and ultimate limit state conditions.
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Date Issued: 1991
PURL: http://purl.flvc.org/fcla/dt/14709
Subject Headings: Precast concrete construction--Testing, Post-tensioned prestressed concrete construction--Testing, Bridges, Concrete--Models
Format: Document (PDF)

Title: Improved design methods for evaluating the performance of landfill double liner systems.
Creator: Shivashankar, Mirle R., Florida Atlantic University, Fluet, J. E. Jr., Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Many modern landfills are constructed with double liner systems. Leachate leakage rates through double liner systems are calculated using recently developed formulations which are theoretically correct for leakage detection system (LDS) materials that have unrestricted lateral flow properties. But their applicability to geonets, the most commonly used LDS material, has yet to be determined. In double liner systems, the leakage through the primary liner, the properties of the LDS material, and...
Show moreMany modern landfills are constructed with double liner systems. Leachate leakage rates through double liner systems are calculated using recently developed formulations which are theoretically correct for leakage detection system (LDS) materials that have unrestricted lateral flow properties. But their applicability to geonets, the most commonly used LDS material, has yet to be determined. In double liner systems, the leakage through the primary liner, the properties of the LDS material, and the slope of the LDS determine the flow patterns in the LDS. These flow patterns are then used to determine the amount of leachate, if any, which leaks through the bottom liner into the ground. This thesis describes the experimental determination of the flow patterns in the geonets and their relationships to established design formulations.
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Date Issued: 1995
PURL: http://purl.flvc.org/fcla/dt/15197
Subject Headings: Sanitary landfills--Leaching, Sanitary landfills--Linings, Geosynthetics
Format: Document (PDF)

FAU Theses and Dissertations (35)	+ -
FAU Undergraduate Student Research (1)	+ -

Reinforced concrete--Corrosion (5)	+ -
Concrete--Cracking (3)	+ -
Fly ash (3)	+ -
Geosynthetics (3)	+ -
Fiber reinforced plastics (2)	+ -

Fire resistant materials (2)	+ -
Fracture mechanics (2)	+ -
Pipe, Plastic--Testing (2)	+ -
Reinforced concrete--Environmental testing (2)	+ -
Retaining walls (2)	+ -
Sanitary landfills--Linings (2)	+ -
Seawater corrosion (2)	+ -
Soil stabilization (2)	+ -
Thermodynamics (2)	+ -
Acoustic emission testing (1)	+ -
Asphalt cement--Additives (1)	+ -
Breakwaters (1)	+ -
Bridges -- Aerodynamics (1)	+ -
Bridges -- Vibration -- Prevention (1)	+ -
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poster (1)	+ -

Reddy, Dronnadula V. (36)	+ -
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Department of Civil, Environmental and Geomatics Engineering (5)	+ -

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