Download or read book Long term Performance of Corrosion Inhibitors Used in Repair of Reinforced Concrete Bridge Components written by Moavin Islam and published by DIANE Publishing. This book was released on 2003 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary objective of the project was to determine the effectiveness of cathodic protection, electrochemical chloride extraction, and corrosion-inhibitor treatment systems installed during the SHRP effort through the long-term evaluation of 32 field test sites and a number of laboratory concrete slab specimens. The FHWA program required monitoring the long-term performance of corrosion inhibitor treatments on selected components of four bridges that were treated and evaluated under SHRP C-103. Three evaluations over a period of 5 years were conducted on structures located in Minnesota, New York and Pennsylvania, and two evaluations were conducted on a structure in Washington State. An analysis of the results concluded that neither of the corrosion inhibitors evaluated in this study, using the specified repairs and exposed to the specific environments, provided any corrosion-inhibiting benefit. Shrinkage cracking plagued repairs at all test sites except for the Washington site.
Download or read book Corrosion Inhibitors for Concrete Bridges written by Amir Mirmiran and published by . This book was released on 2004 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deicing salts and salt-water spray can cause serious corrosion problems for reinforced concrete bridge structures. These problems can lead to costly and labor-intensive repair and even replacement of the structure. Surface applied corrosion inhibitors are potentially a useful and cost effective way to prolong the life of existing structures. The purpose of this research project was to evaluate the effectiveness of commercially available corrosion inhibitors for surface treatments of existing reinforced concrete bridges. Reinforced concrete specimens were cast with different levels of initial chloride contents, coated with one of six products tested, and placed in accelerated corrosion environments. Each manufacturer donated their corresponding products for use in the experiment. The manufacturers were also given the test matrix and parameters in advance of the product application and invited to participate in the application process. Environmental conditions, voltmeter, and half cell potential readings were taken on a weekly basis in accordance with ASTM standards. Intermittently, some of these specimens were removed from their environments and evaluated on a visual, mass loss, strength loss, and chloride content basis. This data was then compiled and compared to each other and to control specimens located in a non-corrosive environment. It was found that surface applied corrosion inhibitors delay the onset of corrosion and the speed of the corrosion process. It was also found that a maximum chloride content of 0.5% by cement weight exists beyond which none of the inhibitor products were useful. Suggestions for further research in this area of study are also included.
Download or read book Evaluation of the Effectiveness of Surface Applied Corrosion Inhibitors for Concrete Bridges written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Deicing salts and salt-water spray can cause serious corrosion problems for reinforced concrete bridge structures. These problems can lead to costly and labor intensive repair and even replacement of the structure. Surface applied corrosion inhibitors are potentially a useful and cost effective way to prolong the life of existing structures. The purpose of this research project was to evaluate the effectiveness of commercially available corrosion inhibitors for surface treatments of existing reinforced concrete bridges. Reinforced concrete specimens were cast with different levels of initial chloride contents, coated with one of six products tested, and placed in accelerated corrosion environments. Each manufacturer donated their corresponding products for use in the experiment. The manufacturers were also given the test matrix and parameters in advance of the product application and invited to participate in the application process. Environmental conditions, voltmeter, and half cell potential readings were taken on a weekly basis in accordance with ASTM standards. Intermittently, some of these specimens were removed from their environments and evaluated on a visual, mass loss, strength loss, and chloride content basis. This data was then compiled and compared to each other and to control specimens located in a non-corrosive environment. It was found that surface applied corrosion inhibitors delay the onset of corrosion and the speed of the corrosion process. It was also found that a maximum chloride content of 0.5% by cement weight exists beyond which none of the inhibitor products were useful. Suggestions for further research in this area of study are also included.
Download or read book A Bibliography on the Corrosion and Protection of Steel in Concrete written by E. Escalante and published by . This book was released on 1979 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Manual on Service Life of Corrosion damaged Reinforced Concrete Bridge Superstructure Elements written by Ali Akbar Sohanghpurwala and published by Transportation Research Board. This book was released on 2006 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Corrosion Inhibitors for Concrete Bridge Deck Patches and Overlays written by Michael M. Sprinkel and published by . This book was released on 2003 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents the results to date of a national pooled fund study initiated in August 1996 to evaluate the long-term performance of bridges and outdoor exposure slabs damaged by chloride-induced corrosion that have concrete containing corrosion inhibiting admixtures and that had topical applications of inhibitors prior to being patched and overlaid. The study includes 156 exposure slabs, 4 bridge decks with overlays, and 1 patched bridge substructure. A total of 136 exposure slabs were constructed to simulate overlay and patch repairs, and 20 full-depth slabs were constructed to simulate new construction. Each repaired slab was constructed with one of four levels of chloride to cause corrosion. The new slabs were ponded to cause corrosion. Previous reports provide details on the construction and initial condition of the exposure slabs and the construction and initial condition of the repaired bridges. The results presented here are based on quarterly nondestructive measurements between September 1997 and June 2001, visual inspections of the exposure slabs, and tensile bond test results and visual inspections of reinforcement removed from the exposure slabs that were patched and overlaid. Overlays cracked and delaminated on exposure slabs that were fabricated with 15 lb/yd3 of chloride ion because of corrosion of the top mat of reinforcement. There was no difference in the performance of overlays constructed with and without inhibitors and topical treatments. Overlays and patches with and without inhibitor treatments placed on and in slabs with 3, 6, and 10 lb/yd3 of chloride are performing satisfactorily. However, results do not show reductions in the tendency for corrosion that can be attributed to the inhibitors. Overlays and patches with and without inhibitor treatments on and in the five bridges indicate mixed results. Corrosion is occurring in the majority of the repairs done with and without inhibitor treatments. The corrosion-inhibiting treatments do not seem to be reducing corrosion in the bridges and, in fact, may be increasing corrosion. It is not obvious that corrosion is occurring in the full-depth slabs constructed with and without inhibitors to represent new construction. The slabs do not show signs of corrosion-induced cracking after 5 years of ponding. Topical applications of inhibitors did not affect the bond strength of the overlays. Overlays containing Rheocrete 222+ and 7 percent silica fume had lower bond strengths. Overlays on base concretes with the higher chloride content had lower bond strengths. In summary, this project does not show any benefit from the use of the corrosion inhibiting admixtures and the topical applications made to the chloride-contaminated concrete surfaces prior to placement of the patches and overlays. Additional years of monitoring of the exposure slabs and bridges may provide useful results.
Download or read book Evaluation of Select Methods of Corrosion Control Corrosion Prevention and Repair in Reinforced Concrete Bridges written by Habib Tabatabai and published by . This book was released on 2009 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of the Effectiveness of Surface Applied Corrosion Inhibitors for Concrete Bridges written by Anna Kaye Cook and published by . This book was released on 2004 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: Prevention of Corrosion in Concrete, Corrosion of Metal in Reinforced Concrete, Reinforced Concrete, Structural Engineering, Civil Engineering.
Download or read book Corrosion Protection written by Yash Paul Virmani and published by . This book was released on 1998 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recognizing the burden that reinforcing steel corrosion imposes on natural resources, the Federal Highway Administration established Corrosion Protection for Concrete Bridges as one of the high-priority areas (HPAs) in its Structures Research Program. This report summarizes the progress made through research efforts conducted under these programs. The results presented cover (A) corrosion control in new concrete constructions (adequate concrete cover, quality concrete, rebar coatings, corrosion inhibiting admixtures, and corrosion protection of prestressed concrete bridge members) and (B) corrosion control for rehabilitation of existing concrete structures (conventional rehabilitation methods, cathodic protection, and electrochemical removal of chloride).
Download or read book Multiple Corrosion Protection Systems for Reinforced Concrete Bridge Components written by and published by . This book was released on 2011 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Eleven systems containing epoxy-coated reinforcement (ECR) in combination with another corrosion-protection system are evaluated using the rapid macrocell, southern exposure, cracked beam, linear polarization resistance, and field tests. The systems include bars pretreated with zinc chromate to improve the adhesion between the epoxy and the reinforcing steel, two epoxies with improved adhesion to the reinforcing steel, one inorganic corrosion inhibitor (calcium nitrite), two organic corrosion inhibitors (Rheocrete® 222+ and HycreteTM), an epoxy-coated bar with a primer containing microencapsulated calcium nitrite, three epoxy-coated bars with improved adhesion combined with the corrosion inhibitor calcium nitrite, and multiple-coated (MC) bars with an initial 50-microm (2-mil) coating of 98 percent zinc and 2 percent aluminum followed by a conventional epoxy coating. The systems are compared with conventional uncoated reinforcement and conventional ECR. The coatings on all bars are penetrated to simulate the effects of damage during fabrication and placement in the field. The results presented in this report indicate that the coated bars provide superior corrosion protection to the reinforcing steel and that bars with damaged coatings initiate corrosion at chloride contents within concrete that are several times greater and corrode at rates that are typically two orders of magnitude below those exhibited by conventional reinforcement. Limited additional protection is achieved using bars with the primer coating, MC bars, and concrete containing the corrosion inhibitors calcium nitrite and one of the organic corrosion inhibitors, although the latter resulted in reduced compressive strength and reduced resistance to surface scaling. The differences in costs over a 75-year design life are relatively small for coated bars. Cracks in concrete directly over and parallel to the reinforcement, such as found in bridge decks, result in earlier corrosion initiation and higher corrosion rates than obtained with intact concrete for all systems. Epoxies that provide initially high adhesion to the underlying steel provide no advantage over conventional epoxy coatings. All coated bars that were evaluated exhibited corrosion losses at openings through the coating. A reduction in adhesion between an epoxy coating and the reinforcing steel occurs after a period of exposure to corrosive conditions. This reduction increases with increasing chloride content in the concrete and in the presence of cracks and decreases with the use of corrosion inhibitors, with the use of MC reinforcement, and with electrical isolation of the epoxy-coated bars from each other. Corrosion products form under the coating where adhesion has been reduced. For periods up to five years under exposure conditions representative of those in bridge decks, the reduction in adhesion between an epoxy coating and the reinforcing steel did not affect the rate at which coated bars corrode.
Download or read book Field Evaluation of Corrosion Inhibitors for Concrete written by Michael M. Sprinkel and published by . This book was released on 1999 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Four bridge decks were overlayed and patched and one bridge pier was patched using concrete with and without corrosion inhibiting admixtures. Some concrete surfaces received topically applied corrosion-inhibiting treatments prior to placement of the concrete. The repairs were successfully completed, and the initial condition of the repairs is good. Corrosion probes were installed in many of the repairs, and measurements are being made each quarter to determine macrocell current, macrocell potential, and resistance. The probe indicates that corrosion is occurring in repairs done with and without corrosion-inhibiting treatments. No conclusions can be drawn at this time, and the study will continue for a total of 5 years.
Download or read book Calcium Nitrite as a Corrosion Inhibitor in Reinforced Concrete Bridge Decks written by Theodore Hopwood (II) and published by . This book was released on 1988 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The use of calcium nitrate as a corrosion-inhibiting admixture in reinforced concrete has been studied on two bridges - the Kentucky 152 Bridge in Washington County and the Gose Road Bridge in Boyle County. Calcium nitrite was added to concrete used in the slabs, diaphrams and barriers of the KY 152 bridge and only in the slab of the Gose Road Bridge."--Data sheet.
Download or read book Concrete Bridge Protection and Rehabilitation written by Strategic Highway Research Program and published by . This book was released on 1993 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance Evaluation of Various Corrosion Protection Systems of Bridges in Colorado written by Yunping Xi and published by . This book was released on 2004 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corrosion of reinforced concrete structures has been a significant problem for many state and transportation agencies since the application of deicing salts was introduced. Much research has been conducted to develop corrosion protection systems that can prolong the life span of reinforced concrete structures. The Colorado Department of Transportation (CDOT) has several routine and experimental measures to prevent corrosion of the rebar including epoxy-coated rebar, calcium nitrite admixture, organic corrosion inhibitors, a thick cover of quality concrete, and a waterproofing membrane covered by an asphalt overlay. An extensive literature review was performed to collect information on various corrosion protection systems that have been used in the U.S. and around the world. Current CDOT practices in terms of corrosion protection measures were reviewed. A draft inspection plan for Colorado's bridge structures was proposed.
Download or read book Long term performance of corrosion inhibitors used in repair of reinforced concrete bridge components written by and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Corrosion Protection Methods for Reinforced Concrete Highway Structures written by Jennifer L. Kepler and published by . This book was released on 2000 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the 1970s, research projects and field studies have been conducted on different methods for protecting reinforced concrete bridges from corrosion damage. The methods include alternative reinforcement and slab design, barrier methods, electrochemical methods, and corrosion inhibitors. Each method and its underlying principles are described, performance results of laboratory and/or field trials are reviewed, and systems are evaluated based on the results of the trials. Using performance results from the studies and costs obtained from transportation agencies, an economic analysis is used to estimate the cost of each system over a 75-year economic life using discount rates of 2%, 4% and 6%.
Download or read book Corrosion Inhibitors for Steel in Concrete written by Bernhard Elsener and published by CRC Press. This book was released on 2001 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of inhibitors for rehabilitation of reinforced concrete structures is a new field of application and this new volume provides a State of the Art Report on this subject. Corrosion of steel in concrete is one of the major problems for infrastructure such as bridges, tunnels, housing etc. since it leads to spalling of the concrete and loss in cross section of the steel that may cause structural and safety problems. The steel in concrete generally resists corrosion as a result of a passive layer that develops on the metal surface in the alkaline environment of the concrete. Corrosion can occur if these conditions are disturbed, for example, in the presence of chlorides or with carbonation of concrete. Traditional repair methods consist in removing the deteriorated concrete and replacing it but these can be laborious, noisy and very costly. To avoid these disadvantages new methods have been developed in recent years. These include electrochemical procedures and, increasingly, the use of inhibitors. The use of inhibitors for rehabilitation of reinforced concrete structures is a new field of application and this new volume provides a State of the Art Report on this subject.The report, under the editorship of Prof. Bernhard Elsener, was prepared by a Task Group of the EFC Working Party on Corrosion of Reinforcement in Concrete. In a literature review it describes inorganic and organic chemicals that have been proposed and examined as well as the commercial corrosion inhibitors that are available on the market. Protection mechanism and possible effects of inhibitors on concrete properties are described. Practical experience with inhibitors for steel in concrete and the long term effectiveness are considered. The various test methods for evaluating the behaviour of the inhibitors are described and critically assessed. In a rapidly evolving field this State of the Art Report, based mainly on independent not commercial literature, will be of value to corrosion engineers and civil engineers concerned with maintenance and repair of reinforced concrete structures.
