Download or read book Evaluation of Epoxy Coated Reinforcing Steel in Bridge Decks written by Satinder K. Munjal and published by . This book was released on 1981 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Epoxy Coated Reinforcing Steel in Bridge Decks written by Satinder K. Munjal and published by . This book was released on 1981 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Bridge Decks Using Epoxy Coated Reinforcement written by Concrete Reinforcing Steel Institute and published by . This book was released on 1994 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance of Epoxy coated Reinforcing Steel in Highway Bridges written by Kenneth C. Clear and published by Transportation Research Board. This book was released on 1995 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Epoxy coated Reinforcing Steel written by Wallace T. McKeel and published by . This book was released on 1993 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Virginia's first installation of epoxy-coated reinforcing steel, which was opened to traffic in 1977, was evaluated during construction and through 13 years of service. It was apparent at the time of construction that the integrity of the coating application did not meet the requirements of the specifications There were many flaws and holidays in the coatings on all of the bars, and patching with a liquid epoxy compound was not effective. Although the applicability of the findings, which are based on an application that does not represent the best practice, may be limited, useful information on the durability of the coated steel and its role in protecting the deck was developed. It was found that the coated reinforcement was exposed to relatively high chloride concentrations at transverse cracks in the decks early in the life of the structures, but the decks remained in good condition throughout the evaluation period. It was concluded that despite the poor coatings, the coated reinforcing steel contributed to the deck's durability by providing enhanced protection at critical cracked sections. Rebars taken from deck cores showed no signs of rusting, although the steel had a dull dark gray finish that may be underfilm corrosion. No debonding of the coating was evident.
Download or read book written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nondestructive Evaluation of Epoxy coated Reinforcing Bars in Concrete Using Bi electrode Half cell Potential Techniques written by Stephen R. Sharp and published by . This book was released on 2006 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study evaluated two half-cell mapping methods for nondestructive evaluation of epoxy-coated rebar (ECR) in concrete: the semi-fixed bi-electrode and the moving bi-electrode methods. These methods were expected to provide early detection of corrosion-related damage and ensure adequate time for repair. The techniques were evaluated by comparing the half-cell measurements using the two half-cell mapping techniques and measurements using the standard half-cell technique. The study found that in concrete specimens the response of both bi-electrode techniques was similar to that of the standard half-cell technique. Each technique was sensitive enough to distinguish between ponded and unponded regions along the Type I test beams. Although additional research is required to determine exactly how sensitive either bi-electrode technique is for assessing corrosion of ECR in concrete, it is clear that the use of any nondestructive tool for condition surveys of bridge decks would benefit VDOT and Virginia. The author recommends that the Type I test beams used in this study continue to be ponded until corrosion is initiated to aid in understanding the benefit of using the two bi-electrode methods during the various stages of corrosion. In addition, the Virginia Department of Transportation's Structure & Bridge Division should identify two structures that are beginning to show signs of corrosion, one bridge with ECR and the other with bare bar, to be used in a field study to determine if either bi-electrode method would benefit VDOT as a condition survey tool.
Download or read book Field Performance of Epoxy coated Reinforcing Steel in Virginia Bridge Decks written by and published by . This book was released on 2000 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study, the corrosion protection performance of epoxy-coated reinforcing steel (ECR) was evaluated using approximately 250 concrete cores from 18 bridge decks in Virginia. The decks were 2 to 20 years old at the time of the investigation. The deck field inspections included a crack survey and cover depth determination in the right traffic lane. A maximum of 12 cores with the top reinforcement randomly located in the lowest 12th percentile cover depth were taken from each bridge deck. Because of the safety concerns associated with taking cores from the lower steel mat, and to minimize damage to the bridge, a maximum of only 3 cores were taken through the truss bars. The laboratory evaluation of the concrete cores included a visual examination and a determination of the carbonation depth, moisture content, absorption, percent saturation, and chloride content at a 13-mm depth. The rapid chloride permeability test was also performed for the surface and base concrete on samples obtained from the cores taken through the truss bars to determine chloride permeability. The ECR inspection consisted of a visual examination, a damage evaluation, and a determination of coating thickness and adhesion. The condition of the steel underneath the epoxy coating was also evaluated. Adhesion loss of the epoxy coating to the steel surface was detected in all but one deck that was 4 years old and older. The epoxy coatings were debonding from the reinforcing bars. Whereas a bonded coating can be expected to protect the steel, a debonded coating allows chlorides, moisture, and oxygen to reach the steel and initiate a rapid corrosion mechanism. Reinforcing bars in various stages of adhesion loss showed visible signs of a corrosion process underneath the coating, suggesting that ECR will provide little or no additional service life for concrete bridge decks in comparison to bare steel. Other systems that will provide longer protection against chloride-induced corrosion of the reinforcing steel with a higher degree of reliability should be considered.
Download or read book Evaluation of Bridge Decks Using Epoxy Coated Reinforcement written by R.R. Kessler and published by . This book was released on 1994 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Methodology to Evaluate the Corrosion Condition of Bridge Decks Containing Epoxy Coated Reinforcing Steel written by and published by . This book was released on 1995 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the U.S., epoxy coated reinforcing steel has been used extensively in bridge construction for over 15 years. Major studies over the last five years or so have examined past and current practices on the use of epoxy coatings to prevent corrosion of reinforcing steel. These studies and the experiences of some state highway agencies indicate a postential for less service life than previously expected. consequently, it is projected that a methodologoy will be needed to evaluate the corrosion condition of bridge structures containing epoxy coated reinforcing steel. As in the case of bridge structures with black reinforcement, a properly conducted corrosionn condition survey provides the information required to select appropriate repair and/or rehabilitation strategies.
Download or read book Evaluation of Simulated Bridge Deck Slabs Using Uncoated Galvanized and Epoxy Coated Reinforcing Steel written by R. L. McCrum and published by . This book was released on 1993 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Methods of Corrosion Protection and Durability of Concrete Bridge Decks Reinforced with Epoxy coated Bars Phase I written by Lisa M. Samples and published by . This book was released on 1999 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Multiple Corrosion Protection Systems for Reinforced Concrete Bridge Decks written by Matthew O'Reilly and published by . This book was released on 2011 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The performance of corrosion protection systems for reinforcing steel in concrete is evaluated. In addition to conventional and conventional epoxy-coated reinforcement, the corrosion protection systems tested include epoxy coatings with improved adhesion to the underlying steel, conventional and conventional epoxy-coated reinforcement used in conjunction with concrete containing one of three corrosion inhibitors, DCI-S, Rheocrete 222+, or Hycrete, epoxy-coated reinforcement with a microencapsulated calcium nitrite primer, multiple-coated reinforcement with a layer of zinc between the epoxy and steel, and pickled 2205 duplex stainless steel. The systems are evaluated using bench-scale and field tests. Two bridges in Kansas, cast with 2205 stainless steel, are monitored using corrosion potential mapping. Epoxy-coated and multiplecoated bars are evaluated to determine the effect of corrosion loss and time on the disbondment of the epoxy coating. Conventional, galvanized, and epoxy-coated reinforcement are evaluated using impressed current to determine the corrosion loss required to crack concrete for each system. A finite element model is developed to represent general and localized corrosion, and the results are used to develop a relationship between concrete cover, bar diameter, and area of bar corroding, and the corrosion loss required to crack concrete. An analysis of pore solutions expressed from cement pastes containing corrosion inhibitors is performed, with pH and selected ion concentrations measured from solutions collected one and seven days after casting. The results obtained from bench-scale and field test specimens are used to estimate cost effectiveness for each system under a 75-year service life. The results show epoxy coatings significantly reduce the corrosion rate compared to conventional reinforcement. Corrosion inhibitors significantly reduce corrosion rates in uncracked concrete. In cracked concrete, corrosion inhibitors also reduce corrosion rates, but their relative effectiveness is reduced. Specimens containing Hycrete exhibit the lowest corrosion rates; however, field specimens containing Hycrete also show signs of scaling. Epoxies with improved adhesion exhibit no improvement over conventional epoxy-coated reinforcement in terms of corrosion rate or disbondment of the epoxy coating. Multiple-coated reinforcement exhibits significantly less disbondment than epoxy-coated reinforcement. Pickled 2205 reinforcement exhibits the least corrosion among all systems tested. Testing of conventional and galvanized reinforcement indicates galvanized reinforcement requires more than twice as much corrosion loss to crack the surrounding concrete compared to conventional reinforcement."--Technical report documentation page.
Download or read book Performance of Epoxy Coated Rebars in Bridge Decks written by J. L. Smith and published by . This book was released on 1996 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Epoxy coated rebar (ECR) was introduced in the mid 1970s as a means to minimize concrete deterioration caused by corrosion of the reinforcing steel and to extend the useful life of highway structures. This report summarizes the results of investigations performed by highway agencies in the United States and Canada, academia, and the Canadian Strategic Highway Research Program to evaluate the performance of ECR. A total of 92 bridge decks, two bridge barrier rails, and one noise barrier rail was evaluated in the States of California, Indiana, Kansas, Michigan, Minnesota, New York, Ohio, Pennsylvania, Virginia, West Virginia, and Wisconsin, and the provinces of Alberta, Nova Scotia, and Ontario.
Download or read book Increasing Bridge Deck Service Life written by Robert Frosch and published by . This book was released on 2014-12-31 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research program was to examine the efficacy of using alternative materials in a bridge deck from both technical and economic perspectives. For the technical evaluation (Volume 1), a three phase experimental investigation was conducted considering a wide range of corrosion-resistant reinforcing materials. These materials included stainless steels, microcomposite steel, and coated steels considering a variety of metallic and nonmetallic coatings. The first phase evaluated the bond between corrosion-resistant reinforcement and concrete using lap splice tests. The second phase evaluated the cracking behavior of slabs reinforced with corrosion-resistant reinforcement. Finally, the third phase evaluated corrosion resistance under uncracked and cracked conditions using macrocell test specimens. Transverse steel was also tied to the longitudinal steel to simulate actual bridge deck conditions. Recommendations are provided on development and splice lengths for both conventional black and corrosion-resistant reinforcing steel, control of cracks widths, as well as the selection, design, and construction of corrosion-resistant reinforcement. For the economic evaluation (Volume 2), a decision support methodology and associated spreadsheet tool for robust analysis of the cost-effectiveness of alternative material types for bridge deck reinforcement was developed. The two evaluation criteria are agency and user costs, and the input data that influence this criteria include the deck service life, material process, discount rate, detour length, and bridge size. The methodology incorporates analytical techniques that include life cycle analyses to evaluate the long-term cost and benefits of each material over the bridge life; Monte Carlo simulation to account for the probabilistic nature of the input variables; stochastic dominance to ascertain the probability distribution of the outcome that a specific reinforcement material is superior to others; and analytical hierarchical process to establish appropriate weights for the agency and user costs. Methodology is demonstrated using a case study involving three reinforcement material alternatives: traditional (epoxy-coated) steel, zinc-clad steel, and stainless steel. Through this study, it is demonstrated that the use of corrosion-resistant reinforcing materials can significantly increase bridge deck life, reduce agency and user costs associated with bridge deck rehabilitation and maintenance, and thus lower the financial needs for long-term preservation of bridges.
Download or read book An Evaluation of the Performance of Epoxy coated Reinforcing Steel in Concrete Exposure Specimens written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The application of a mineral admixture or a combination of a mineral admixture with corrosion inhibitor are the methods used for the corrosion protection for reinforced concrete bridges. The results of a 1.5-year study on evaluation of three concretes with fly ash, slag cement (SC), and silica fume (SF) and one concrete with silica fume and a corrosion inhibitor (SFD) are presented. The specimens were built to simulate four exposure conditions typical for concrete bridges located in the coastal region or inland where deicing salts are used. The exposure conditions were horizontal, vertical, tidal, and immersed zones. The specimens were kept inside the laboratory and were exposed to weekly ponding cycles of 6% sodium chloride solution by weight. In addition, cover depth measurements from 21 bridge decks and chloride data from 3 bridge decks were used, together with laboratory data, in modeling the service lives of investigated corrosion protection methods. The methods used to assess the condition of the specimens included chloride concentration measurements, corrosion potentials, and corrosion rates (3LP). Additionally, visual observations were performed for identification of rust stains and cracking on concrete surfaces. The results of chloride testing indicate that the amount of chlorides present at the bar level is more than sufficient to initiate corrosion. Chloride and rapid permeability data demonstrate that for low permeable (LP) concretes there appears to be significant difference both in a rate of chloride ingress and in the diffusion coefficients in comparison to the controls. Corrosion potentials agree with corrosion rates and suggest the possibility of an active corrosion process development on control specimens during indoor exposure. The structural cracks that were observed in some specimens appeared to have no influence on the corrosion development on the bars in the vicinity of the these cracks. It was concluded that the silicone and duct tape protection was adequate. The cracking, other than structural, appeared to be related to the reinforcing steel corrosion, except the cracks in the horizontal zone of the specimen with slag cement which were probably caused by the subsidence cracking. The least number of cracks was observed on the SF and SFD specimens. Modeling the time as a function of probability of the end of functional service life (EFSL) was presented. It has been shown that the distributions of surface concentrations of chloride ions (C0) and diffusion constants (Dc) are key elements in the model. Model predictions show that the LP concretes provide much better level of protection against moisture and chlorides than the A4 concrete alone. Application of a corrosion inhibitor causes an elevation of the chloride threshold resulting in an additional increase in time to EFSL. Recommendations are to continue monitoring until cracking has occurred in all specimens to a greater extent to better estimate the service lives of LP concretes than is presently known in the construction of concrete bridge components in Virginia. The specimens with LP concretes and one control (continuous reinforcement in the legs) should be taken to the Hampton Road North 1 Tunnel Island and placed in the brackish water to a depth of the immersed zone at low tide for further exposure to chloride. The other control (non-continuous reinforcement in the legs) should remain in an outdoor exposure in Southwest Virginia like the Civil Engineering Materials Research Laboratory in Blacksburg, Virginia. Also more field studies are needed to better estimate distributions of surface chloride concentration and diffusion coefficient of Virginia bridge decks, and to confirm predicted times to EFSL for LP concretes.
Download or read book Summary Report on the Performance of Epoxy coated Reinforcing Steel in Virginia written by Richard E. Weyers and published by . This book was released on 2006 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: From 1992 to 2006, the Virginia Transportation Research Council and its contract researchers conducted a long-term systematic series of investigations to evaluate the corrosion protection effectiveness of epoxy-coated reinforcement (ECR) and to identify and recommend the best and most cost-effective corrosion protection system for Virginia bridge decks. This report summarizes this research and subsequent efforts to implement alternative reinforcement. The work was conducted, and is reported, in this general order: review of historical performance of ECR, ECR performance in solutions and concrete, and preliminary field investigations; investigation of field performance of bridge decks built with ECR; assessment of alternative corrosion protection methods; development of probabilistic service life models for bridge decks and laboratory assessment of ECR cores extracted from bridge decks to determine service life extension; efforts to implement alternative reinforcement. The series of studies demonstrated that the epoxy coating on ECR naturally degrades in the highly alkaline moist environment within concrete. The subsequent loss of bond, coupled with the inevitable flaws in the coating induced by construction, leads to an estimated service life benefit of ECR of as little as 3 to 5 years. Further, non-critical decks, beams, and substructure elements not exposed to marine environments, particularly on secondary and rural routes, can be cost-effectively constructed and maintained using low-permeability concrete and black reinforcing bar. However, because the Federal Highway Administration requires the use of corrosion-resistant reinforcement, and because ECR cannot provide adequate corrosion protection for structures designed for a 100-year+ service life as currently recommended by FHWA, the report recommends that the Virginia Department of Transportation amend its specifications regarding the use of ECR to require the use of corrosion-resistant metallic reinforcing bars such as MMFX2, stainless steel clad, and solid stainless steel.
