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Title: Strength and durability of fly ash-based fiber-reinforced geopolymer concrete in a simulated marine environment.
Creator: Martinez Rivera, Francisco Javier, Sobhan, Khaled, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: This research is aimed at investigating the corrosion durability of polyolefin fiber-reinforced fly ash-based geopolymer structural concrete (hereafter referred to as GPC, in contradistinction to unreinforced geopolymer concrete referred to as simply geopolymer concrete), where cement is completely replaced by fly ash, that is activated by alkalis, sodium hydroxide and sodium silicate. The durability in a marine environment is tested through an electrochemical method for accelerated corrosion...
Show moreThis research is aimed at investigating the corrosion durability of polyolefin fiber-reinforced fly ash-based geopolymer structural concrete (hereafter referred to as GPC, in contradistinction to unreinforced geopolymer concrete referred to as simply geopolymer concrete), where cement is completely replaced by fly ash, that is activated by alkalis, sodium hydroxide and sodium silicate. The durability in a marine environment is tested through an electrochemical method for accelerated corrosion. The GPC achieved compressive strengths in excess of 6,000 psi. Fiber reinforced beams contained polyolefin fibers in the amounts of 0.1%, 0.3%, and 0.5% by volume. After being subjected to corrosion damage, the GPC beams were analyzed through a method of crack scoring, steel mass loss, and residual flexural strength testing. Fiber reinforced GPC beams showed greater resistance to corrosion damage with higher residual flexural strength. This makes GPC an attractive material for use in submerged marine structures.
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Date Issued: 2013
PURL: http://purl.flvc.org/fau/fd/FA0004037
Subject Headings: Concrete mixing -- Quality control, Green chemistry, Polymer composites, Reinforced concrete -- Corrosion -- Testing, Reinforced concrete construction
Format: Document (PDF)

Title: CRACKING OF CONCRETE DUE TO CORROSION OF VARIOUS EMBEDDED METALS.
Creator: TURNER, DEAN HUDSON., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The objective of this investigati.on was to contribute to the determination of a suitable metallic coating for steel reinforcement in concrete exposed to a marine environment and possibly to stray current. Concrete specimens embedded with steel, aluminum, cadmium, copper, molybdenum, nickel, and galvanized steel were exposed to sea water. Direct current was impressed on these to accelerate corrosion of the reinforcement so that cracking of the concrete could be observed within the time limit...
Show moreThe objective of this investigati.on was to contribute to the determination of a suitable metallic coating for steel reinforcement in concrete exposed to a marine environment and possibly to stray current. Concrete specimens embedded with steel, aluminum, cadmium, copper, molybdenum, nickel, and galvanized steel were exposed to sea water. Direct current was impressed on these to accelerate corrosion of the reinforcement so that cracking of the concrete could be observed within the time limit of the investigation. Aluminum, cadmium, copper, and nickel were found to have no beneficial effect on concrete cracking as compared to steel. In addition, no correlation between oxide-metal volume ratio and concrete time-to-cracking could be observed. It was found that corrosion of molybdenum has little or no tendency to crack concrete and its corrosion potential and active behavior approximates that of steel, indicating it may be an excellent coating.
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Date Issued: 1976
PURL: http://purl.flvc.org/fcla/dt/13820
Subject Headings: Reinforced concrete--Cracking, Underwater concrete construction, Reinforced concrete--Corrosion
Format: Document (PDF)

Title: Experimental and Modeling Study of Chloride Ingress into Concrete and Reinforcement Corrosion Initiation.
Creator: Yu, Hui, Hartt, William H., Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Effects of reinforcement and coarse aggregate on chloride ingression into concrete and reinforcement corrosion initiation have been studied with experimental and modeling (finite element method) analyses. Once specimens were fabricated and exposed to a chloride solution, various experimental techniques were employed to determine the effect of reinforcement and coarse aggregate on time-to-corrosion and chloride ingress and concentration at corrosion locations. Model analyses were performed to...
Show moreEffects of reinforcement and coarse aggregate on chloride ingression into concrete and reinforcement corrosion initiation have been studied with experimental and modeling (finite element method) analyses. Once specimens were fabricated and exposed to a chloride solution, various experimental techniques were employed to determine the effect of reinforcement and coarse aggregate on time-to-corrosion and chloride ingress and concentration at corrosion locations. Model analyses were performed to verify and explain the experimental results. Based upon the results, it was determined that unexpectedly higher chloride concentrations were present on the top of the rebar trace than that to the side at the same depth and an inverse concentration gradient (increasing [Cl-] with increasing depth) occurred near the top of rebars. Also, coarse aggregate volume profile in close proximity to the rebar and spatial distribution of these aggregates, in conjunction with the physical obstruction afforded by reinforcement to chloride flow, complicates concrete sampling for Cl- intended to define the critical concentration of this species to initiate corrosion. Modeling analyses that considered cover thickness, chloride threshold concentration, reinforcement size and shape, and coarse aggregate type and percolation confirmed the experimental findings. The results, at least in part, account for the relatively wide spread in chloride corrosion threshold values reported in the literature and illustrate that more consistent chloride threshold concentrations can be acquired from mortar or paste specimens than from concrete ones.
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Date Issued: 2007
PURL: http://purl.flvc.org/fau/fd/FA00012582
Subject Headings: Reinforced concrete construction--Corrosion, Chlorides--Diffusion rate, Composite reinforced concrete, Concrete--Chemical resistance
Format: Document (PDF)

Title: Performance of anodes in cathodic protection of reinforcing steel in concrete.
Creator: Venugopalan, Sivaraman., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Experiments were conducted on a simulated reinforced concrete bridge deck to test different anodes as part of a cathodic protection system. Both carbon based and titanium based anodes were tested. All the anodes were driven at predetermined current densities. Current off polarized potentials of steel and anode were monitored over six months. After this period, cores were extracted from slabs containing a part of anode and steel and then broken at the anode-concrete and steel-concrete...
Show moreExperiments were conducted on a simulated reinforced concrete bridge deck to test different anodes as part of a cathodic protection system. Both carbon based and titanium based anodes were tested. All the anodes were driven at predetermined current densities. Current off polarized potentials of steel and anode were monitored over six months. After this period, cores were extracted from slabs containing a part of anode and steel and then broken at the anode-concrete and steel-concrete interface to measure the pH at these interfaces. Differences in the pH values at the anode-concrete interface were compared to determine the performance of the different anodes. Carbon based anodes operated at a higher potential and produced anode corrosion products of lower pH when compared to titanium based anodes.
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Date Issued: 1990
PURL: http://purl.flvc.org/fcla/dt/14658
Subject Headings: Reinforcing bars--Cathodic protection, Reinforced concrete--Corrosion
Format: Document (PDF)

Title: ESTIMATION OF THE PHYSICAL PROPERTIES OF CORRODING REBAR IN REINFORCED CONCRETE USING BIOT-STOLL MODEL INVERSION.
Creator: Brogden, Matthew, Beaujean, Pierre-Philippe, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: The detection of rebar corrosion in reinforced concrete is important due to the high costs of corrosion related damages to infrastructure. One such method of rebar corrosion lies in the use of non-destructive ultrasonic testing. To date, acoustic methods require either the training of an artificial neural network or a theory of acoustic wave propagation. Using a more complete acoustic model such as the Biot-Stoll model avoids algorithm training requirements by directly modeling the acoustic...
Show moreThe detection of rebar corrosion in reinforced concrete is important due to the high costs of corrosion related damages to infrastructure. One such method of rebar corrosion lies in the use of non-destructive ultrasonic testing. To date, acoustic methods require either the training of an artificial neural network or a theory of acoustic wave propagation. Using a more complete acoustic model such as the Biot-Stoll model avoids algorithm training requirements by directly modeling the acoustic environment. A problem with this method lies in the complexity of the model and the selection of free parameters. The problem of parameter selection is addressed by a series of targeted measurements using ultrasonic transducers on a set of existing reinforced concrete samples placed in a saltwater solution. This data can then be analyzed by a non-linear least squares solver to produce a better fit for the acoustic signal.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00014032
Subject Headings: Reinforcing bars--Corrosion, Reinforced concrete, Acoustics, Ultrasonics
Format: Document (PDF)

Title: Optimized Parameters Fitting of a Poro-Elastic Acoustic Model with Ultrasonic Measurements for the Monitoring of Corroding Rebar in Reinforced Concrete.
Creator: Shaffer, Samuel, Beaujean, Pierre-Philippe, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: Traditional techniques of observing cracking within reinforced structures can be invasive, leading to an increased risk of added corrosion to structures already undergoing corrosive processes. The research presented in this document improves upon a nondestructive method for detecting early crack formation in reinforced concrete. This method includes using acoustic signaling to add a layer of salt water between the sensor and analyzed sample. Following the collection of surface and rebar echo...
Show moreTraditional techniques of observing cracking within reinforced structures can be invasive, leading to an increased risk of added corrosion to structures already undergoing corrosive processes. The research presented in this document improves upon a nondestructive method for detecting early crack formation in reinforced concrete. This method includes using acoustic signaling to add a layer of salt water between the sensor and analyzed sample. Following the collection of surface and rebar echo responses, an adapted version of the novel Biot-Stoll method is used to model sound propagation for poro-elastic mediums. Testing of model parameters and variables has improved the root mean square error (RMSE) by up to 63.7% when studying the full signal, and up to 62.6% for the rebar echo locations. These improvements signify better curve fitting between simulated and measured responses, which lead to increased accuracy in the model parameter outputs.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014265
Subject Headings: Reinforced concrete, Reinforcing bars--Corrosion, Ultrasonic testing
Format: Document (PDF)

Title: Microbial Induced Degradation in Synthetic Fiber Reinforced Concrete Samples in South Florida.
Creator: Parkinson, Jacqueline Cecile, Presuel-Moreno, Francisco, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Synthetic fiber reinforced concrete sample sets were exposed to two different environments. One set, of six samples, was exposed to filtered seawater in the lab with wet and dry cycles, while the other set of samples was exposed, on a barge, to the marine environment, in the intracoastal waterways, at SeaTech. The samples were exposed for 8 months, and then removed for experimental and mechanical testing. Upon removal, the barge samples were photographed to observe surface organisms that were...
Show moreSynthetic fiber reinforced concrete sample sets were exposed to two different environments. One set, of six samples, was exposed to filtered seawater in the lab with wet and dry cycles, while the other set of samples was exposed, on a barge, to the marine environment, in the intracoastal waterways, at SeaTech. The samples were exposed for 8 months, and then removed for experimental and mechanical testing. Upon removal, the barge samples were photographed to observe surface organisms that were attached to each sample. The barge samples, after cleaning, were then exposed to UV light to observe surface bacteria. The barge samples were also taken to Harbor Branch facility for DNA testing, and then sent in for sequencing. This sequencing was used to identify the organisms that were present inside the concrete samples. An Indirect Tensile Strength Test, IDT, was performed on both sets of samples to observe the first crack, max load, and fracture toughness of each sample. The Barge samples had a lower first crack, max load, and fracture toughness, which means that it took less force to break these samples, than the Seawater samples. As the fiber content increased, the Seawater samples grew stronger, while the Barge samples grew weaker. Also, as the fiber content increased, the biodiversity found on the surface of the Barge samples increased as well.
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Date Issued: 2019
PURL: http://purl.flvc.org/fau/fd/FA00013251
Subject Headings: Fiber-reinforced concrete, Florida, Concrete--Deterioration, Microbes
Format: Document (PDF)

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: Comparative evaluation of the performance of concrete wall panels, with and without fiber reinforcement.
Creator: Germain, Gerson S., Florida Atlantic University, Reddy, Dronnadula V.
Abstract/Description: This investigation addresses the evaluation of the increase in structural integrity of concrete wall panels by the addition of polypropylene fibers. The test methodology used was the evaluation of flexural (simply-supported and cantilever), shear (in-plane and punching), and impact behavior. The concrete panels comprised sets with (i) regular reinforcement (ACI code based), (ii) Reinforced concrete panels: 0.2% fibers with minimum ACI reinforcement, FRC 2, (iii) 0.3% fibers without...
Show moreThis investigation addresses the evaluation of the increase in structural integrity of concrete wall panels by the addition of polypropylene fibers. The test methodology used was the evaluation of flexural (simply-supported and cantilever), shear (in-plane and punching), and impact behavior. The concrete panels comprised sets with (i) regular reinforcement (ACI code based), (ii) Reinforced concrete panels: 0.2% fibers with minimum ACI reinforcement, FRC 2, (iii) 0.3% fibers without reinforcement, FRC 3, and (iv) plain beams without reinforcement. The instrumentation consisted of deflection and electrical strain gages, a slope indicator for slope testing, and an oscilloscope with a camera attachment for monitoring load and energy traces in impact testing. The normalized (adjusted for concrete strength variations) ultimate load and energy values were compared. The findings indicated enhancement of ductility and shear strength for the fiber reinforced specimens, which are very desirable for sudden and impact loading conditions associated with hurricane-type loading.
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Date Issued: 2000
PURL: http://purl.flvc.org/fcla/dt/12678
Subject Headings: Concrete walls--Design and construction, Reinforced concrete, Fiber
Format: Document (PDF)

Title: THE IMPACT CORROSION HAS ON THE DEGRADATION OF MECHANICAL PROPERTIES OF CARBON STEEL REBARS IN HIGH PERFORMANCE CONCRETE.
Creator: Rosa-Pagan, Angel R., Presuel-Moreno, Francisco, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: A significant amount of reinforced concrete structures in the USA are reaching the design life span of 50 years. Degradation of these infrastructure due to corrosion presents an economical, safety and quality of life challenge for our society. Being able to study and determine the conditions of our infrastructure, perform maintenance before failure and predict failure before occurrence has become critical for our society and our way of life. This study was performed to add to existing...
Show moreA significant amount of reinforced concrete structures in the USA are reaching the design life span of 50 years. Degradation of these infrastructure due to corrosion presents an economical, safety and quality of life challenge for our society. Being able to study and determine the conditions of our infrastructure, perform maintenance before failure and predict failure before occurrence has become critical for our society and our way of life. This study was performed to add to existing research in the understanding of the relationships between the corrosion current of the embedded carbon steel rebars in reinforced concrete, rebar mass loss due to corrosion and the degradation of the mechanical properties of the carbon steel embedded in high performance concrete structures. The study also aimed to study the influence of different independent variables such as the chloride solution reservoir size and the concrete composition of the prepared specimens for the study. Specimens for the study were prepared by embedding three carbon steel size #4 rebars in blocks of high performing concrete with different admixture to enhance their performance against corrosion. To initiate corrosion specimens were exposed to accelerated chloride transport method (electromigration). To accelerate corrosion some samples were selected for anodic polarization and additional electromigration. After corrosion initiation, the rebars Open Circuit Potential (OCP) and corrosion current (Icorr) were periodically measured using a galvanostat device from April 2017 to August 2021. The OCP average values showed that all the rebars considered in this study were in active corrosion. Faraday’s law was used to determine the rebar calculated mass loss from the measured corrosion current and the elapse time between measurements. The rebar mass loss was in turn used to model the loss of the physical properties of the rebar (yield strength, ultimate strength, and ultimate strain) using (Vanama & Ramakrishnan, 2020) model. Analysis of these parameters results showed a direct relationship between the measured corrosion current and the calculated mass loss of the corroding rebar. The study also showed a direct relationship between the calculated mass loss of the corroding rebar and the degradation of the physical properties of the rebar.
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Date Issued: 2021
PURL: http://purl.flvc.org/fau/fd/FA00013843
Subject Headings: Corrosion, Reinforced concrete--Deterioration, Carbon steel, High strength concrete
Format: Document (PDF)

Title: Influence of pozzolanic admixtures on concrete pore water pH, chloride diffusion and chloride binding.
Creator: Charvin, Stephanie., Florida Atlantic University, Hartt, William H.
Abstract/Description: This report describes the results obtained from reinforced concrete slabs having different fly ash and silica fume content. The specimens are submitted to periodic seawater ponding. PH measurements as well as free and total chloride analyses were achieved at 1213 days in order to study the alkalinity, resistance to chloride ingress and binding properties afforded by each mix design. Water absorption experiments were also conducted at different relative humidities and in water. Pore water pH...
Show moreThis report describes the results obtained from reinforced concrete slabs having different fly ash and silica fume content. The specimens are submitted to periodic seawater ponding. PH measurements as well as free and total chloride analyses were achieved at 1213 days in order to study the alkalinity, resistance to chloride ingress and binding properties afforded by each mix design. Water absorption experiments were also conducted at different relative humidities and in water. Pore water pH was found to decrease with increasing admixture content and increasing relative humidity. The permeability to chloride ions was significantly reduced in the fly ash blends whereas most of the silica fume blends exhibited effective diffusion coefficients and chloride concentrations at the depth of steel marginally better than the controls. Both the fly ash and silica fume blends showed similar binding capacity at a given replacement ratio, the percentage of bound chloride increasing with increasing admixture content.
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Date Issued: 1999
PURL: http://purl.flvc.org/fcla/dt/15664
Subject Headings: Reinforced concrete construction--Corrosion, Concrete--Additives
Format: Document (PDF)

Title: Adhesive Joint Analyses Using Ansys CZM Modeling of a Prefabricated Hybrid Concrete-GFRP-CFRP Unit.
Creator: Kabaluk, Maksim, Arockiasamy, Madasamy, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: The present study reviews applications of FRP materials joined by structural adhesives in civil engineering. FE analysis with mix-mode cohesive zone material model (CZM) was used to analyze stresses induced in two structural adhesives joining dissimilar materials (concrete GFRP-CFRP) of the hybrid-composite unit. The predicted failure loads, displacements and deformation by the 3-D non-linear FE analysis in the present study are in good agreement with the experimental results of the hybrid...
Show moreThe present study reviews applications of FRP materials joined by structural adhesives in civil engineering. FE analysis with mix-mode cohesive zone material model (CZM) was used to analyze stresses induced in two structural adhesives joining dissimilar materials (concrete GFRP-CFRP) of the hybrid-composite unit. The predicted failure loads, displacements and deformation by the 3-D non-linear FE analysis in the present study are in good agreement with the experimental results of the hybrid-composite unit reported by Deskovic et al. (1995). The contact analysis revealed a complex 3-D state of stress in the bondlines of both structural adhesives. It is concluded that higher joint strength is expected when a ductile adhesive is used.
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Date Issued: 2019
PURL: http://purl.flvc.org/fau/fd/FA00013222
Subject Headings: Adhesive joints, Fiber reinforced polymers, Composites, Concrete
Format: Document (PDF)

Title: ACOUSTIC EMISSION ASSOCIATED WITH EMBEDDED METAL CORROSION IN A CONCRETE SLAB.
Creator: MARSHALL, RICHARD MELBOURNE., Florida Atlantic University, Dunn, Stanley E., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: Measured values of attenuation with distance, amplitude distribution, and propagation velocity of acoustic emissions associated with embedded metcil corrosion induced cracking in a concrete slab are presented. An extensive review of acoustic emission signal processing techniques and theoretical background material is also included. The study points out how attenuation and propagation velocity of the acoustic emission signal affects various signal processing techniques and verifies an...
Show moreMeasured values of attenuation with distance, amplitude distribution, and propagation velocity of acoustic emissions associated with embedded metcil corrosion induced cracking in a concrete slab are presented. An extensive review of acoustic emission signal processing techniques and theoretical background material is also included. The study points out how attenuation and propagation velocity of the acoustic emission signal affects various signal processing techniques and verifies an amplitude distribution spreading rrodel. The need for further defirlition of attentuation values caused by fluid loading of the concrete surface is also discussed.
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Date Issued: 1982
PURL: http://purl.flvc.org/fcla/dt/14129
Subject Headings: Reinforced concrete--Corrosion, Acoustic emission testing
Format: Document (PDF)

Title: Chloride thresholds for initiation of corrosion of steel reinforcement in concrete.
Creator: Perks, Robert Adam., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: A study was performed of variables that affect the chloride threshold for corrosion of reinforcement, including pore water alkalinity, water-to-cement ratio, the use of Florida aggregate, and the addition of fly ash. To accomplish this, specimens were subjected to a periodic wet-dry ponding cycle using 15% by weight NaCl solution. Half cell potential and macrocell current measurements were taken to determine the time to corrosion. Upon active corrosion, the specimens were removed from the...
Show moreA study was performed of variables that affect the chloride threshold for corrosion of reinforcement, including pore water alkalinity, water-to-cement ratio, the use of Florida aggregate, and the addition of fly ash. To accomplish this, specimens were subjected to a periodic wet-dry ponding cycle using 15% by weight NaCl solution. Half cell potential and macrocell current measurements were taken to determine the time to corrosion. Upon active corrosion, the specimens were removed from the ponding cycle and dissected. Powder samples were collected from the concrete at the steel depth to ascertain the total chloride concentration. The determination of the pore water pH was attempted using a leaching method. To date only a portion of the specimens have displayed corrosion. The role of cement alkalinity and water-to-cement ratio in affecting corrosion resistance is reported and the results are discussed within the context of designing concrete structures for corrosion resistance.
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Date Issued: 2000
PURL: http://purl.flvc.org/fcla/dt/12721
Subject Headings: Steel--Corrosion, Reinforced concrete, Chlorides
Format: Document (PDF)

Title: Atmospheric Corrosion Study of Weathering Steel Using Sensor Technology.
Creator: Hereng, Yann, Granata, Richard D., Florida Atlantic University
Abstract/Description: This research tests the corrosion resistance of weathering steel against carbon steel exposed to dry and humid cycles during laboratory experiments. Various environments are tested and include the following parameters: chloride concentration, pH and wetting time. Corrosion values from weight loss analysis are given and studied for the same environments. X-ray diffraction characterized the formation of different oxides as a function of the environment and gave a better understanding on the...
Show moreThis research tests the corrosion resistance of weathering steel against carbon steel exposed to dry and humid cycles during laboratory experiments. Various environments are tested and include the following parameters: chloride concentration, pH and wetting time. Corrosion values from weight loss analysis are given and studied for the same environments. X-ray diffraction characterized the formation of different oxides as a function of the environment and gave a better understanding on the formation of the protective patina on the weathering steel, and validated that chamber experiments reproduce field conditions. The study is supported by the design, test and validation of an easily deployable galvanic atmospheric corrosion sensor that allowed the monitoring of the corrosion rate on an hourly basis.
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Date Issued: 2007
PURL: http://purl.flvc.org/fau/fd/FA00012526
Subject Headings: Steel, Structural--Corrosion, Reinforced concrete construction
Format: Document (PDF)

Title: DETECTION OF DETERIORATION OF REINFORCED CONCRETE BY ACOUSTIC EMISSION TECHNIQUES.
Creator: WENG, MING-YUAN., Florida Atlantic University, Dunn, Stanley E., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: In this investigation acoustic emission techniques were employed to detect deterioration of reinforced concrete. As a result of various laboratory tests, acoustic emission activity was found to be due to development of cracking only. Acoustic emission techniques were able to locate cracks in a specimen by linear location. Various acoustic emission parameters such as amplitude, signal shape and frequency were also analyzed and discussed. It was concluded that acoustic emission techniques...
Show moreIn this investigation acoustic emission techniques were employed to detect deterioration of reinforced concrete. As a result of various laboratory tests, acoustic emission activity was found to be due to development of cracking only. Acoustic emission techniques were able to locate cracks in a specimen by linear location. Various acoustic emission parameters such as amplitude, signal shape and frequency were also analyzed and discussed. It was concluded that acoustic emission techniques provided a feasible method for detection of deterioration and cracking of steel reinforced structures in laboratory studies as well as in a field environment.
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Date Issued: 1980
PURL: http://purl.flvc.org/fcla/dt/14042
Subject Headings: Acoustic emission testing, Reinforced concrete--Corrosion
Format: Document (PDF)

Title: The assessment of bond for cathodically polarized pretensioning steel in concrete.
Creator: Dohlen, Knut Herman., Florida Atlantic University, Hartt, William H.
Abstract/Description: Pretensioned concrete members require a certain bond strength between the steel and concrete to maintain prestress force. Previous studies have indicated that when reinforcing steel in concrete is cathodically polarized, a chemical change of the cement near the steel-concrete interface occurs; and this can reduce the bond strength. In the present research experiments were conducted with concrete specimens that contained either a non-stressed seven wire steel tendon or a single strand through...
Show morePretensioned concrete members require a certain bond strength between the steel and concrete to maintain prestress force. Previous studies have indicated that when reinforcing steel in concrete is cathodically polarized, a chemical change of the cement near the steel-concrete interface occurs; and this can reduce the bond strength. In the present research experiments were conducted with concrete specimens that contained either a non-stressed seven wire steel tendon or a single strand through the longitudinal direction. The specimens were cathodically polarized with current densities ranging between 50 and 2500 mA/m^2 of steel. Upon achieving a pre-determined charge density transfer, the steel was pulled relative to the concrete until the bond was broken. Results indicate that a total charge density transfer of up to 14000 A*h/m^2 of steel, may introduce an average 16 percent decrease in ultimate bond strength. This and other data were evaluated in order to assess if cathodic protection, as utilized for corrosion control, is likely to compromise structural integrity of pretensioned concrete members and structures.
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Date Issued: 1998
PURL: http://purl.flvc.org/fcla/dt/15543
Subject Headings: Cathodic protection, Reinforced concrete--Corrosion
Format: Document (PDF)

Title: Concrete diffusivity and its correlation with chloride deposition rate on concrete exposed to marine environments.
Creator: Echevarria, Victor Anthony., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description: The aim of this study was to investigate the diffusion of chloride ions into concrete samples that were exposed in scenarios that simulate the splash, tidal, atmospheric, and immersed portions of a marine structure. To study the atmospheric deposition, the project also investigated the relationship between chloride ion deposition on the wet candle and its accumulation into concrete samples. Results from the wet candle experiment indicated that between 2% and 45% of the chlorides deposited per...
Show moreThe aim of this study was to investigate the diffusion of chloride ions into concrete samples that were exposed in scenarios that simulate the splash, tidal, atmospheric, and immersed portions of a marine structure. To study the atmospheric deposition, the project also investigated the relationship between chloride ion deposition on the wet candle and its accumulation into concrete samples. Results from the wet candle experiment indicated that between 2% and 45% of the chlorides deposited per square meter of exposed area could be found within the concrete samples. After 6 months, slag G1a blocks showed the most resistance to chloride penetration in the tidal and splash simulations. After 10 months of exposure, fly ash samples had the slowest rates of diffusion in the tidal simulation while the fly ash + silica fume samples and the slag samples measured similar rates of diffusion within the tidal zone. After 90 days of curing, cylinders composed of 20% fly ash & 8% silica fume measured the highest average resistivity values and were found to be less vulnerable to chloride ion penetration than the 20% fly ash and the 50% slag concrete through rapid migration tests.
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Date Issued: 2012
PURL: http://purl.flvc.org/FAU/3358557
Subject Headings: Reinforced concrete, Construction, Corrosion, Composite reinforced concrete, Corrosion, Testing, Concrete, Fluid dynamics, Concrete, Chemical resistance, Chlorides, Diffusion rate
Format: Document (PDF)

Title: Analysis of blast/explosion resistant reinforced concrete solid slab and T-Beam bridges.
Creator: Abdelahad, Firas A., Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: This study presents and illustrates a methodology to calculate the capacity of an existing reinforced concrete bridge under a non-conventional blast load due to low and intermediate pressures. ATBlast program is used to calculate the blast loads for known values of charge weight and stand off distance. An excel spreadsheet is generated to calculate ultimate resistance, equivalent elastic stiffness, equivalent elastic deflection, natural period of the beam, the maximum deflection, and the...
Show moreThis study presents and illustrates a methodology to calculate the capacity of an existing reinforced concrete bridge under a non-conventional blast load due to low and intermediate pressures. ATBlast program is used to calculate the blast loads for known values of charge weight and stand off distance. An excel spreadsheet is generated to calculate ultimate resistance, equivalent elastic stiffness, equivalent elastic deflection, natural period of the beam, the maximum deflection, and the maximum rotation in the support for a simple span solid slab and T-Beam bridges. The allowable rotation could be taken as to two degrees. Naval Facility Engineering Command (NAVFAC) approach was adopted, where the inputs were material properties, span length, and area of reinforcement. The use of the Fiber Reinforced Polymer for increasing the capacity of an existing bridge is also presented in this study. Parametric studies were carried out to evaluate the performance of the solid slab and T-Beam bridges under the assumed blast load.
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Date Issued: 2008
PURL: http://purl.flvc.org/fcla/flaent/EN00154040/68_1/98p0132d.pdf, http://purl.flvc.org/FAU/58001
Subject Headings: Concrete beams, Vibration, Bridges, Concrete, Fatigue, Reinforced concrete construction, Bridges, Concrete, Design and construction
Format: Document (PDF)

Title: Flexural Behavior of Concrete Using Basalt FRP Rebar.
Creator: Trotsek, Dylan, Arockiasamy, Madasamy, Florida Atlantic University, College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
Abstract/Description: The objective of this research is to determine if the deflection equations currently adopted in ACI 440.1r-15 and previously ACI 440.1r-06 accurately reflect the flexural behavior of an overreinforced Basalt Fiber Reinforced Polymer (BFRP) concrete beam. This was accomplished with experimental, analytical and numerical models. The experiment consisted of two beams doublyreinforced with BFRP rebar. A three-point flexural test on beams with a 30 in. clear span was performed and the deflections...
Show moreThe objective of this research is to determine if the deflection equations currently adopted in ACI 440.1r-15 and previously ACI 440.1r-06 accurately reflect the flexural behavior of an overreinforced Basalt Fiber Reinforced Polymer (BFRP) concrete beam. This was accomplished with experimental, analytical and numerical models. The experiment consisted of two beams doublyreinforced with BFRP rebar. A three-point flexural test on beams with a 30 in. clear span was performed and the deflections were recorded with a dial gauge and LVDT system. This data was compared to the equations from ACI 440.1r-06, ACI 440.1r-15, Branson’s equation and a numerical model created in ANSYS Mechanical APDL. Experimental results show a stiffer beam than expected when compared to the four predictive models for deflection. This can be due to the level of over-reinforcement and the small clear-span to depth ratio. Further research should be conducted to determine the cause for the additional stiffness.
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Date Issued: 2017
PURL: http://purl.flvc.org/fau/fd/FA00004920, http://purl.flvc.org/fau/fd/FA00004920
Subject Headings: Reinforced concrete construction--Mathematical models., Structural analysis (Engineering), Fiber-reinforced concrete.
Format: Document (PDF)

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