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 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 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 Two Corrosion Inhibitors Using Two Surface Application Methods for Reinforced Concrete Structures written by Stephen R. Sharp and published by . This book was released on 2004 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study investigated the use of penetrating corrosion inhibitors to extend the life of existing reinforced concrete bridge decks. The use of assisted (vacuum/pressure injection) and unassisted (diffusion) treatment methods and two inhibitors were evaluated. The inhibitors were FerroGard 903, from Sika Corp., and TPS-II, from Surtreat International. Testing was performed on exposure slabs with 15 lb/yd3 of NaCl in the top layer and no NaCl in the bottom layer. The slab design was a variation of the specimen design provided in ASTM G109, with each slab containing nine steel reinforcing rods instead of three. The exposure slabs had either a uniform cover over the top pieces of steel or an inclined cover over the steel. TPS-II was also evaluated on the deck of a bridge in Orange County, Virginia. The study found that when applied to the concrete surface, neither inhibitor penetrated the concrete to reach the steel reinforcement. The vacuum/pressure injection method showed promise but requires refinement. In addition, based on macro-cell measurements, a sufficient quantity of inhibitor can be injected into the concrete to reduce the charge passed.

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 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 Performance Evaluation of Corrosion Inhibitors and Galvanized Steel in Concrete Exposure Specimens written by Jerzy Zemajtis and published by . This book was released on 1999 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corrosion inhibitor admixtures (CIA) and galvanized reinforcing steel (GS) are used for the corrosion protection for reinforced concrete bridges. The results of a 3.5-year evaluation of exposure specimens containing CIA from three different manufacturers and GS 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. The methods used to assess the condition of the specimens included chloride concentration measurements, corrosion potentials, and corrosion rates. 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 indicate no significant difference either in a rate of chloride ingress or in the diffusion coefficients for concretes with and without CIA. Corrosion potentials were the most negative for the Bare Steel (BS) specimen prepared with the Armatec 2000 corrosion inhibitor and generally indicated a 90% probability of active corrosion. Corrosion potentials were similar for the two BS control specimens and the BS specimen prepared with Rheocrete 222 and generally indicated an uncertain probability of corrosion. Corrosion potentials were the least negative for the BS specimen prepared with DCI-S corrosion inhibitor and generally indicated a 90% probability of no corrosion. Rate of corrosion measurements were the highest for the BS control specimens and the one prepared with A2000 and the most recent data suggest corrosion damage in 2 to 10 years. Although early rate of corrosion measurements were higher or about the same as for BS control specimens, recent measurements were slightly lower for the specimen prepared with Rheocrete 222 and suggest corrosion damage in 10 to 15 years. Rate of corrosion measurements were consistently the lowest for the BS specimens prepared with DCI-S and indicate corrosion damage is expected in 10 to 15 years. The corrosion potential and rate of corrosion data indicate that DCI-S is the only CIA evaluated that clearly provides some level of corrosion protection. A direct comparison of the GS specimens to the BS specimens is not possible because the measured potential refers to the zinc oxide and not to the steel. Nevertheless, the potential data agree with the chloride and permeability data, as well as with the visual observations, and indicate the damaging effect of a high concentration of chloride ions on the GS. At low and moderate chloride exposures, however, GS does provide corrosion protection. Recommendations are to continue monitoring until sufficient cracking has occurred in all specimens to provide for making a better estimate of the service lives of CIA and GS used in the construction of concrete bridge components in Virginia. The specimens with CIA and one control (continuous reinforcement in the legs) should be taken to the Hampton Road North Tunnel Island and placed in the brackish water to a depth of the Immersed Zone at low tide for further exposure to chloride. The specimens with GS and 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.

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.

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 An Evaluation of New Inhibitors for Rebar Corrosion in Concrete written by Brian D. Chambers and published by . This book was released on 2003 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: The corrosion of reinforcing steel in concrete is estimated to affect more than 50% of the 575,000 bridges in the United States. One approach to mitigating this problem is to use corrosion-inhibitive compounds admixed into the concrete paste. This study sought to examine the corrosion inhibition performance of a series of compounds admixed into high-quality concrete and to delineate the effects of these compounds on the concrete with regard to the corrosion process. A series of eight compounds were admixed into Type A4 concrete. The compounds tested were aminoethylethanolamine, aminothiophenol, di-sodium Beta-glycerophosphate, calcium nitrite, di-n-butyl sulfoxide, lithium nitrate, sodium metasilicate, and nitrilotriphosphonic acid. Concrete blocks were cast, into which were placed 0.009-in.-diameter 1040 steel wires. The corrosion rate was assessed via a resistance change measurement (RCM) of these wires over time using a temperature-corrected four-point resistance measurement. The time-to-open circuit for the wires was also monitored. RCM was compared to (1) electrochemical impedance spectroscopy results of tests conducted in a simulated pore solution, and (2) chloride permeability measurements of the concrete as per ASTM C 1202. The effect of the admixtures on the compressive strength and density of the concrete was also assessed. RCM and time-to-open circuit results showed that four test inhibitors had equal or better corrosion prevention at 2 years of testing compared to a widely used commercial mix (DCI). These test inhibitors included di-sodium Beta-glycerophosphate (0.283 mol/cu ft and 0.815 mol/cu ft), aminoethylethanolamine (0.815 mol/cu ft), lithium nitrate (0.815 mol/cu ft), and sodium metasilicate (0.815 mol/cu ft). After 100 weeks, 33% to 44% of the wires were active in concrete admixed with these test compounds, whereas only 25% of the wires were active in concrete admixed with DCI. This research has also shown that the performance of a corrosion inhibitor in high-quality concrete is a function of numerous interrelated factors that are not predicted from any single laboratory test. These tests provide promising results for alternative inhibitive admixtures for standard Type A4 concrete. It is recommended that additional tests be conducted on concrete mixtures containing slag and fly ash using multiple concentrations of the four most promising inhibitors. Further testing may lead to the implementation of a better corrosion-inhibiting admixture, thus increasing the service life of bridges.

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 Corrosion Protection Performance Evaluation of Low Permeable Concretes in Exposure Specimens written by Jerzy Zemajtis and published by . This book was released on 1999 with total page 152 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 (CO) 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 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 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 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 Corrosion of Reinforcement in Concrete written by M Raupach and published by Woodhead Publishing. This book was released on 2014-01-23 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: Given the widespread use of reinforced concrete in infrastructure, understanding the corrosion of this material is of major importance. As a result there has been a wealth of research into catalysts, inhibitors and effective means of monitoring the rate of corrosion. Corrosion of reinforcement in concrete: mechanisms, monitoring, inhibitors and rehabilitation techniques summarises some of the most significant research and its implications.The book begins by reviewing findings from various experiments designed to test the corrosion rate of metals induced by a range of factors. Later chapters discuss techniques for monitoring and testing for corrosion. The book concludes by assessing important methods of prevention, including corrosion inhibitors, protective coatings and electrochemical methods for protection, together with rehabilitation procedures for susceptible structures.Filled with practical examples and written by a distinguished team of international contributors, Corrosion of reinforcement in concrete: mechanisms, monitoring, inhibitors and rehabilitation techniques is an essential reference for civil engineers using reinforced concrete. Summarises research into catalysts, inhibitors and effective means of monitoring the rate of corrosion Concludes by assessing important methods of prevention

Download or read book Evaluation of Corrosion Inhibitors written by Perumalsamy N. Balaguru and published by . This book was released on 2001* with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corrosion of reinforcement is a global problem that has been studied extensively. The use of good quality concrete and corrosion inhibitors seems to be an economical, effective and logical solution, especially for new structures. A number of laboratory studies are available on the performance of various corrosion inhibiting admixtures. But studies on concrete used in the field are rare. A new bypass constructed by the New Jersey Department of Transportation provided a unique opportunity to evaluate the admixtures in the field. Five new bridge decks were used to evaluate four corrosion inhibiting admixtures. The concrete used in the four bridge decks had one of the following admixtures: DCI-S, XYPEX C-1000, Rheocrete 222+, Ferrogard901. All the admixtures are commercially available and used in the field. The fifth deck was used as a control. All the decks with admixtures had black steel where as the control deck had epoxy coated bars.