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 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 Bridge Deck Service Life Prediction and Costs written by and published by . This book was released on 2007 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: The service life of Virginia's concrete bridge decks is generally controlled by chloride-induced corrosion of the reinforcing steel as a result of the application of winter maintenance deicing salts. A chloride corrosion model accounting for the variable input parameters using Monte Carlo resampling was developed. The model was validated using condition surveys from 10 Virginia bridge decks built with bare steel. The influence of changes in the construction specifications of w/c = 0.47 and 0.45 and w/cm = 0.45 and a cover depth increase from 2 to 2.75 inches was determined. Decks built under the specification of w/cm = 0.45 (using slag or fly ash) and a 2.75 inch cover depth have a maintenance free service life of greater than 100 years, regardless of the type of reinforcing steel. Galvanized, MMFX-2, and stainless steel, in order of increasing reliability of a service life of greater than 100 years, will provide a redundant corrosion protection system. Life cycle cost analyses were conducted for polymer concrete and portland cement based overlays as maintenance activities. The most economical alternative is dependent on individual structure conditions. The study developed a model and computer software that can be used to determine the time to first repair and rehabilitation of individual bridge decks taking into account the time for corrosion initiation, time from initiation to cracking, and time for corrosion damage to propagate to a state requiring repair.
Download or read book Bridge Deck Cracking Evaluation written by and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transverse cracking of concrete bridge decks continues to be an issue for the Montana Department of Transportation (MDT) and is considered a common issue reported among many state departments of transportation (DOTs). In the last 25 years with the introduction of high performance concrete (HPC) in bridge decks to lower permeability and with the use of finer ground cements (to increase early age strength gain and construction schedule), the susceptibility of bridge deck cracking has increased. Cracking commonly leads to a reduction in service life and increased maintenance costs, primarily due to accelerated corrosion of reinforcing steel in the deck. Identifying the causes of bridge deck cracking and providing prevention can be complex and challenging, but is very important for maintaining longevity of the bridge deck. To assist MDT with diagnosing and mitigating the causes of transverse cracking of bridge decks, WJE implemented a multi-disciplinary approach including a literature review, field inspections, bridge deck instrumentation, laboratory evaluations, and finite element modeling (FEM). From this research, WJE found the primary causes were related to non-uniform moisture gradients, drying shrinkage, and specific winter curing procedures. Based on these findings, WJE recommended improvements to mixture proportions, construction practices, and design considerations.
Download or read book Impact of Deck Cracking on Durability written by Fouad Fanous and published by . This book was released on 2000 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete bridge decks subjected to corrosive environment because of the application of de-icing chemical could deteriorate at a rapid rate. In an effort to minimize corrosion of the reinforcement and the corresponding delaminations and spalls, the Iowa Department of Transportation started using epoxy-coated rebars (ECR) in the top mat of reinforcing around 1976 and in both mats 10 years later. The overall objective of this research was to determine the impact of deck cracking on durability and estimate the remaining functional service life of a bridge deck. This was accomplished by conducting a literature review, visually inspecting several bridge decks, collecting and sampling test cores from cracked and uncracked areas of bridge decks, determining the extent to which epoxy-coated rebars deteriorate at the site of cracks, and evaluating the impact of cracking on service life.
Download or read book Bridge Service Life Design written by Elizabeth Rose Bales and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: High costs and traffic disruption associated with the deterioration of reinforced concrete bridge decks because of corrosion have sparked renewed interest in service life design. Reinforced concrete bridge decks are exposed to chlorides from deicing salts; when the chlorides reach the steel reinforcement, they initiate corrosion. This study supports the adoption of the methodology described in fib Bulletin 34, Model Code for Service Life Design, for reinforced concrete bridge decks in Virginia. Concrete mixture properties and environmental exposure conditions were characterized. Values particular to regions within Virginia and suggested default values were identified and organized in a database to support the development of service life design guidelines. The predicted service life for eight bridge decks using low-cracking concrete and corrosion-resistant reinforcement (VDOT Reinforcement Class I, MMFX, ASTM 1035) was evaluated. The service life model was also implemented in a life-cycle cost analysis for a case study bridge, which found superior reliability of corrosion-resistant reinforcement from a life-cycle perspective. In addition to supporting the implementation of service life design, several investigations identified key assumptions and variables in the service life model and identified critical areas for future characterization. The partial differential equation for apparent chloride diffusion was solved with both an approximate analytical approach and a numerical approach. Delays in the application of deicing salt were investigated using the numerical approach, and a ramp-type function for surface chloride concentration was explored using the analytical approach. Aging coefficients based on curing were also considered. A sensitivity analysis identified the aging coefficient and the surface chloride concentration as the most critical variables. The study concluded that sufficient data are available to implement the fib Model Code for Service Life Design, but that caution in interpreting results is warranted because of the high uncertainty associated with the most critical variables. According to the results of the service life analyses, the regional climatic variability and differences in mix design across Virginia indicate that a "one-size-fits-all" approach to bridge deck specifications may not be appropriate. The use of corrosion-resistant steel and low-cracking concrete mixtures can provide a substantial (greater than 100 years) bridge deck service life
Download or read book Service Life Extension of Virginia Bridge Decks Afforded by Epoxy Coated Reinforcement written by MC. Brown and published by . This book was released on 2006 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study was conducted on concrete core samples each containing a single top-mat reinforcing steel bar from ten bridge decks in Virginia. Two of the bridges contained conventional, uncoated mild reinforcing steel (Bare), and eight of the bridges were constructed with epoxy-coated reinforcement (ECR). The bridges ranged in age from 4 to 18 years, and were built under same specifications for concrete water-to-cement ratio (w/c) and cover depth. In the laboratory, the subject cores were prepared and corrosion activity was monitored via electrochemical impedance spectroscopy while subject to cyclic ponding of a 3 % NaCl solution over a 22-month exposure period. The relative corrosion performance of the Bare and ECR bars were evaluated, by comparison of the time to corrosion initiation and time to failure, as designated by visible cracking of the concrete cover. A stochastic model was employed, using bootstrap resampling techniques, to project the corrosion protection service life extension provided by epoxy-coated reinforcement as compared to Bare steel for the population of Virginia bridge decks. Less than 25 % of all Virginia bridge decks built under specifications in place since 1981 were projected to corrode sufficiently to require rehabilitation within 100 years, regardless of bar type. The corrosion service life extension attributable to ECR in bridge decks was found to be approximately 5 years beyond that of Bare steel.
Download or read book Performance and Service Life of Low slump concrete Bridge Deck Overlays in New York written by William P. Chamberlin and published by . This book was released on 1990 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fifty randomly selected concrete bridge decks in New York State, overlaid with low-slump concrete, were studied in 1985 after an average of 5 years of service. The investigation included recording surface defects, measuring delamination and half-cell potentials, and sampling and testing for deck chloride profile. Conclusions are drawn with regard to the nature and significance of the observed damage, and estimates are made of service life expectancy. Policy implications for the New York State Department of Transportation are discussed.
Download or read book Rethinking Bridge Deck Longevity and Maintenance with Portland Cement Polymer Concrete written by Andrew P. Agosto and published by . This book was released on 2008 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge deck deterioration in the northern Midwest creates significant costs to state Departments of Transportation (DOT's) in the region. The fundamental cause of the problem is low tensile strength and water permeable reinforced concrete resulting in deck cracking and ultimately reinforcing bar corrosion. Portland Cement Polymer Concrete (PCPC) combined with a design approach tailored to its advantages could virtually eliminate early deck deterioration and the associated costs providing an alternative asset management path for bridge decks. Bridge decks would no longer have to be removed from their substructure every fifteen years and replaced. The results would be higher quality, longer lasting bridge decks with lower life cycle costs. This project will demonstrate the feasibility and methodology of such a strategy. This project will develop a strategy that combines innovative concrete materials, novel design and cost analysis that enhances the longevity and reduces the life cycle cost of highway bridge decks. The project is expected to show significant life-cycle cost advantages to using a high performance bridge deck material.
Download or read book Strategies to Increase the Service Life of Concrete Bridge Decks written by O. Burkan Isgor and published by . This book was released on 2017 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Extending the Service Life of Existing Bridges by Increasing Their Load Carrying Capacity written by Roland H. Berger and published by . This book was released on 1978 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: A catalog of bridge deficiencies is developed based on the inspection of over 140 deficient bridges located in Illinois, Florida, Pennsylvania, California, and Tennessee. A classification of structure types is developed for concrete, steel and timber bridges. Deficiencies are related to the structure classification system and a hierarchy of the most common deficiencies established. Techniques presently utilized by state highway departments to correct deficiences are described and evaluated. Several innovative techniques for increasing the load carrying capacity are also described. Utilizing these techniques, increased capacity values are developed. Cost factors are also analyzed and graphic presentations which show the relative merit of each system are presented.
Download or read book Transportation written by U S Government Accountability Office (G and published by BiblioGov. This book was released on 2013-06 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although bridge roadway surfaces (decks) were expected to provide relatively maintenance-free service for about 40 years, the Federal Highway Administration has found that some unprotected bridge decks require major repair within 5 to 10 years, and often must be replaced after 15 years of service. The major cause of this early deterioration is corrosion of the reinforcing steel bars in the bridge deck, brought about by chloride chemicals which are used to melt snow. About $6.3 billion is needed to restore the Nation's Federal-aid system bridge decks. Most States have indicated that, if present conditions are not improved, their currently reparable bridge decks will continue to deteriorate, and eventually require complete replacement at a much higher cost. A review of the problem indicates that a number of bridges in the Federal-aid system do not have a protective system on their decks. They contain either no areas or only small areas where chloride levels are high enough to cause bridge deck deterioration. If these bridge decks were protected with one of the systems now used for new bridge construction, significant savings could be realized by avoiding more expensive repairs later. Lack of funds is the primary reason that States have not installed protective systems on existing bridges. Funds available for bridge repair are generally budgeted for bridges so deteriorated that replacement of the deck is the only option. As a result, those bridge decks with little or no deterioration will continue to deteriorate, and eventually require repairs or replacements that are much more costly than the cost of the protective systems. Weaknesses also exist in the Federal Highway Administration's evaluation process to assess the performance of the technologies in extending the service life of the bridge decks.
Download or read book High Performance Concrete Bridge Decks A Fast Track Implementation Study Volume 1 Structural Behavior written by Robert J. Frosch and published by Purdue University Press. This book was released on 2008-11-01 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transverse cracking of concrete bridge decks is problematic in numerous states. Cracking has been identified in the negative and positive moment regions of bridges and can appear shortly after opening the structure to live loads. To improve the service life of the bridge deck as well as decrease maintenance costs, changes to current construction practices in Indiana are being considered. A typical bridge deck was instrumented which incorporated the following: increased reinforcement amounts, decreasing reinforcement spacing, and high-performance, low-shrinkage concrete. The low shrinkage concrete was achieved using a ternary concrete mix. The objective of this research was to determine the performance, particularly in terms of transverse cracking and shrinkage, of a bridge incorporating design details meant to reduce cracking. Based on measurements from the bridge, it was determined that maximum tensile strains experienced in the concrete were not sufficient to initiate cracking. An on-site inspection was performed to confirm that cracking had not initiated. The data was analyzed and compared with the behavior of a similarly constructed bridge built with nearly identical reinforcing details, but with a more conventional concrete to evaluate the effect of the HPC. Based on this study, it was observed that full-depth transverse cracks did not occur in the structure and that the use of HPC lowered the magnitude of restrained shrinkage strains and resulting tensile stresses.
Download or read book Extending the Service Life of Existing Bridges by Increasing Their Load Carrying Capacity written by Roland H. Berger and published by . This book was released on 1978 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: A catalog of bridge deficiencies is developed based on the inspection of over 140 deficient bridges located in Illinois, Florida, Pennsylvania, California, and Tennessee. A classification of structure types is developed for concrete, steel and timber bridges. Deficiencies are related to the structure classification system and a hierarchy of the most common deficiencies established. Techniques presently utilized by state highway departments to correct deficiences are described and evaluated. Several innovative techniques for increasing the load carrying capacity are also described. Utilizing these techniques, increased capacity values are developed. Cost factors are also analyzed and graphic presentations which show the relative merit of each system are presented.
Download or read book Service Life Estimation and Extension of Civil Engineering Structures written by Vistasp M. Karbhari and published by Elsevier. This book was released on 2010-12-20 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Service life estimation is an area of growing importance in civil engineering both for determining the remaining service life of civil engineering structures and for designing new structural systems with well-defined periods of functionality. Service life estimation and extension of civil engineering structures provides valuable information on the development and use of newer and more durable materials and methods of construction, as well as the development and use of new techniques of estimating service life. Part one discusses using fibre reinforced polymer (FRP) composites to extend the service-life of civil engineering structures. It considers the key issues in the use of FRP composites, examines the possibility of extending the service life of structurally deficient and deteriorating concrete structures and investigates the uncertainties of using FRP composites in the rehabilitation of civil engineering structures. Part two discusses estimating the service life of civil engineering structures including modelling service life and maintenance strategies and probabilistic methods for service life estimation. It goes on to investigate non-destructive evaluation and testing (NDE/NDT) as well as databases and knowledge-based systems for service life estimation of rehabilitated civil structures and pipelines. With its distinguished editors and international team of contributors Service life estimation and extension of civil engineering structures is an invaluable resource to academics, civil engineers, construction companies, infrastructure providers and all those with an interest in improving the service life, safety and reliability of civil engineering structures. A single source of information on the service life of reinforced concrete and fibre-reinforced polymer (FRP) rehabilitated structures Examines degradation mechanisms in composites for rehabilitation considering uncertainties in FRP reliability Provides an overview of probabilistic methods for rehabilitation and service life estimation of corroded structures
Download or read book Technologies for Improving the Evaluation and Repair of Concrete Bridge Decks written by and published by . This book was released on 1998 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance of Epoxy coated Reinforcement in Iowa Bridge Decks written by Han-Ching Wu and published by . This book was released on 1999 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete bridge decks subjected to corrosive environment, due to the application of de-icing chemical, could deteriorate at a rapid rate. In an effort to minimize corrosion of the reinforcement and the corresponding delaminations and spalls, the Iowa Department of Transportation (IADOT) started using epoxy-coated rebars (ECR) in the top mat of reinforcing around 1976 and in both mats about 10 years later. The ultimate objective of this research was to determine the impact of deck cracking on durability and estimate the remaining functional service life of a bridge deck. The overall objectives of this work were obtained by conducting a literature review, visually inspecting several bridge decks, collecting and sampling test cores from cracked and uncracked areas of bridge decks, determining the extent to which epoxy coated rebars deteriorate at the site of cracks, and evaluating the impact of cracking on service life.
