Download or read book Transverse Cracking of High Performance Concrete Bridge Decks After One Season Or Six to Eight Months written by and published by . This book was released on 2006 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cracking is a major problem with newly placed concrete decks. These decks tend to develop full depth, transverse cracks and partial depth longitudinal cracks within a few months of the concrete being placed. A literature review showed that several other states had experienced similar problems. A review of data from Ohio bridge decks showed weak correlations between deck cracking and slump, time of year when the deck was placed, shrinkage, chloride permeability and compressive strength, but there was no clear relationship between cracking and any of these properties. Data also suggested that using a coarse aggregate with an absorption> 1% may help mitigate deck cracking but will not always stop it. As part of this study, 3 bridge decks were instrumented. One was a standard class "S" concrete deck and the other two were high performance concrete. The class "S" deck showed only hairline cracking after 1 year, but transverse cracking occurred in the HPC decks. Instruments were placed in the decks to monitor strains. From the data, it appears that cracking is caused by several factors. High heat of hydration caused the plastic concrete to expand. When the concrete sets and cools, tensile stressed develop. Further tensile stresses develop through drying shrinkage. Restraining the deck against normal thermal movement contributes to additional tensile stress. Autogeneous shrinkage, where high heats of hydration cause water evaporation during hydration, and plastic shrinkage may cause more tensile stress. Recommendations for mitigating cracking include using lower cement contents, adding pozzolans and retarders, using slightly higher water/cement ratios, using larger aggregates, taking steps to limit shrinkage and eliminating restraints.

Download or read book Transverse Cracking of Bridge Decks Influence of Temperature and Restrained Shrinkage written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ohio Department of Transportation started a program of replacement of bridge decks by high performance concrete decks but the decks started showing cracks after just six to eight months or a season of construction. This study was taken up to ascertain the causes of this early cracking with emphasis on the study of the role of temperature and restrained shrinkage in cracking. Analysis of data from ODOT about its previously cast decks about their location, mix design, slump, compressive strength, average shrinkage, month of casting, ninety day chloride penetration values and temperature differential showed vast scatter, indicating that deck cracking is the compounded effect of several factors acting together and implied an in-depth study in various directions. To gain an insight into the role of temperature and restrained shrinkage in cracking, an experiment was done in an ODOT project involving a phased replacement of deck of a bridge (on US 127) over still water in Richland Township of Darke County in Ohio. Prior to casting, four pairs of vibrating wire gages were placed at the top and bottom of the reinforcement cage of deck at following locations * On the mid-span between two beams * Over the pier * Over the beam * Over the beam pier intersection. Hourly strains and corresponding Temperatures were measured and recorded for fifteen months. Numerical analysis and analytic study was done on the data obtained from site. Both phases of construction showed a different behavior so far as the pattern of strain generation is concerned. It was observed that the gages having least external restraint developed highest strains. The deck showed a wavy behavior with upward curvature at locations where deck had a beam below and downward curvature for locations where deck has no beam (restraint) below it. The temperature was seen to become a potential source for cracking only when a vast difference of temperature existed along the cross section of deck. Even after one year of casting the deck, only minor cracking was observed. This unexpected behavior of deck was attributed to good construction practices, especially proper curing.

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 Transverse Cracking of High Performance Concrete Bridge Decks written by Prakash Ganesh and published by . This book was released on 2006 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cracking is a major problem with newly placed concrete decks. These decks tend to develop full depth, transverse cracks and partial depth longitudinal cracks within a few months of the concrete being placed. A literature review showed that several other states had experienced similar problems. A review of data from Ohio bridge decks showed weak correlations between deck cracking and slump, time of year when the deck was placed, shrinkage, chloride permeability and compressive strength, but there was no clear relationship between cracking and any of these properties. Data also suggested that using a coarse aggregate with an absorption> 1% may help mitigate deck cracking but will not always stop it. As part of this study, three bridge decks were instrumented. One was a standard class S concrete deck and the other two were high performance concrete. The class S deck showed only hairline cracking after 1 year, but transverse cracking occurred in the HPC decks. Instruments were placed in the decks to monitor strains. From the data, it appears that cracking is caused by several factors. High heat of hydration caused the plastic concrete to expand. When the concrete sets and cools, tensile stresses develop. Additional tensile stresses develop through drying shrinkage. Restraining the deck against normal thermal movement contributes to additional tensile stress. Autogeneous shrinkage, where high heats of hydration cause water evaporation during hydration, and plastic shrinkage may cause more tensile stress. Recommendations for mitigating cracking include using lower cement contents, adding pozzolans and retarders, using slightly higher water/cement ratios, using larger aggregates, taking steps to limit shrinkage and eliminating restraints.

Download or read book Controlling Early age Transverse Cracking in High Performance Concrete Bridge Decks written by Eric Ying Xian Liu and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Material and Construction Optimization for Prevention of Premature Pavement Distress in PCC Pavements written by and published by . This book was released on 2008 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Phase I, the research team contacted each of 16 participating states to gather information about concrete and concrete material tests. A preliminary suite of tests to ensure long-term pavement performance was developed. The tests were selected to provide useful and easy-to-interpret results that can be performed reasonably and routinely in terms of time, expertise, training, and cost. The tests examine concrete pavement properties in five focal areas critical to the long life and durability of concrete pavements: (1) workability, (2) strength development, (3) air system, (4) permeability, and (5) shrinkage. The tests were relevant at three stages in the concrete paving process: mix design, preconstruction verification, and construction quality control. In Phase II, the research team conducted field testing in each participating state to evaluate the preliminary suite of tests and demonstrate the testing technologies and procedures using local materials.

Download or read book Cause and Control of Transverse Cracking in Concrete Bridge Decks written by M. Ala Saadeghvaziri and published by . This book was released on 2002 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many concrete bridge decks develop transverse cracking and most of these cracks develop at early ages, some right after construction and some after the bridge has been opened to traffic for a period of time. Structural design factors have not been the subject of much research in the past and they were the main thrust of this research study. Using 2-D and 3-D linear and nonlinear finite element models many design factors such as girder stiffness, deck thickness, girder spacing, relative stiffness of deck to girder, amount of reinforcements, etc., were studied. The research study also included a comprehensive review of the existing literature as well as survey of 24 bridges in the state of New Jersey. Results of each research task are presented and discussed in detail. Furthermore, based on analytical results and literature review, the effect of various factors are quantified and specific recommendations for possible consideration in design are made.

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 Phase I Minimization of Cracking in New Concrete Bridge Decks written by Nicole Duffala and published by . This book was released on 2016 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cracking of newly constructed high-performance concrete (HPC) bridges is a problem recognized nationwide and the Nevada Department of Transportation has been plagued with this distress in their HPC concrete bridge decks. This research effort is a strategic attempt to reduce or eliminate random cracking that is caused by restrained shrinkage in new concrete bridge decks constructed in Nevada. The overall objective will be achieved through a three phase research program of which the results of Phase I are being reported in this document. Phase I research findings provide a synthesis of state, regional, and national practices and knowledge on factors contributing to HPC bridge deck cracking. With respect to materials and mixture proportioning, the overwhelming conclusion is that the shrinkage of the concrete mixture, especially at early-ages, must be reduced and the concrete’s resistance to cracking must be Improved. A rigorous, Phase II laboratory experiment was designed and is presented herein. This Phase II laboratory experiment focuses on local materials and will assess the properties of concrete mixtures that are related to early-age drying shrinkage restraint cracking. Ultimately, these research findings could be used to revise standard specifications and special provisions for Nevada DOT bridge decks and eventually reduce the overall incidence of restraint cracking due to concrete drying shrinkage.

Download or read book Durability of Concrete Bridge Decks written by and published by . This book was released on 1965 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transverse Cracking in Newly Constructed Bridge Decks written by Paul D. Krauss and published by . This book was released on 1996 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Phase 1 Report on the Development of Predictive Model for Bridge Deck Cracking and Strength Development written by and published by . This book was released on 2009 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: Early-age cracking, typically caused by drying shrinkage (and often coupled with autogenous and thermal shrinkage), can have several detrimental effects on long-term behavior and durability. Cracking can also provide ingress of water that can drive chemical reactions, such as alkali-silica reaction (ASR) and sulfate attack. Because of the problems associated with cracking observed in bridge decks, and the impact of early-age cracking on long-term performance and durability, it is imperative that bridge decks be constructed with minimal early-age cracking and that exhibit satisfactory long-term performance and durability. To achieve these goals for bridges in the state of Texas, a research team has been assembled that possesses significant expertise and background in cement chemistry, concrete materials and durability, structural performance, computational mechanics (finite difference/element), bridge deck construction and maintenance, monitoring of in-site behavior of field structures, and the development of test methods and specifications aimed at practical implementation by state highway departments. This proposal describes a laboratory- and field-based research program aimed at developing a bridge deck cracking model that will ultimately be integrated into ConcreteWorks, a suite of software programs developed for TxDOT by this same research team.

Download or read book Study of Early Age Bridge Deck Cracking in Nevada and Wyoming written by Dale P. Bentz and published by CreateSpace. This book was released on 2012-01-31 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: In late 2009, the Echo Wash and Valley of Fire bridge decks were constructed in the Lake Mead National Recreation area in Nevada. Within six months after installation, in early 2010, both decks exhibited considerable transverse cracking, with some cracks extending through the thickness of the deck. Similar cracking was observed in the Snake River bridge deck in Wyoming. This report details the results of a two-pronged approach to examining the causes of such cracking.

Download or read book Cracking in Concrete Bridge Decks written by Tony R. Schmitt and published by . This book was released on 1995 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: The causes of cracking in bridge decks are investigated and procedures are recommended to alleviate the problem. Forty continuous steel girder bridges, thirty-seven composite and three noncomposite bridges are evaluated. Field surveys conducted to document cracking patterns and to determine the crack density of each bridge are described. Information collected from construction documents, field books, and weather data logs is presented and compared to the observed levels of cracking to identify correlations between cracking and the variables studied. Thirty-one variables are considered such as material properties, site conditions, construction procedures, design specifications, age of bridge and traffic volume. Based on the research reported herein, cracking in monolithic bridge decks increases with increasing values of concrete slump, percent volume of water and cement, water content, and compressive strength, and decreasing values of air content (especially below 6.0%). Bridge deck overlays placed with zero slump concrete consistently exhibit high levels of cracking. Cracking in overlays also increases as placement lengths increase. High maximum air temperatures and large changes in air temperature on the day of casting aggravate cracking in monolithic bridge decks. High average air temperatures and large changes in air temperature similarly aggravate cracking in bridge deck overlays. Both monolithic and two layer bridges with fixed-ended girders exhibit increased cracking near the abutments compared to those with pin-ended girders.

Download or read book Cause of Cracking in High Performance Concrete Bridge Decks written by Marco A. Frías and published by . This book was released on 2006 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bridge Deck Cracking and Composite Action Analyses written by Hani H. Nassif and published by . This book was released on 2010 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comparison of Crack Performance of Structural Slab Bridge Decks with Stringer Supported Bridge Decks written by Michael A. Adams and published by . This book was released on 2011 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of several cracks on reinforced concrete bridge decks is a serious, growing problem that not only affects the state of Ohio, but also the United States as a whole. Many bridge decks constructed within the last 10 years in Ohio have already shown varying levels and patterns of cracking. Regardless of the bridge design type, length of the spans, deck thickness, and concrete mixture designs, cracks will develop on reinforced concrete bridge decks. Bridge deck cracking is a critical issue because cracks allow harmful and corrosive chemicals to penetrate the concrete and deteriorate the reinforcing steel that is embedded in the concrete. If proper precautions and steps are not taken, then this could lead to rapid deterioration leading to costly maintenance problems and need for possible replacement. The Ohio Department of Transportation's current bridge inspection procedure requires periodic inspections of the whole bridge. ODOT's inspection procedure only offers a qualitative assessment of the bridge and does not give a quantitative measurement of the bridge deck cracking. The primary objective of this report was to evaluate the cracking performance of structural slab bridge decks and compare with that of bridges constructed with stringer supports in the ODOT's District 3. Extensive crack surveys were completed for six bridge decks, three structural slab supported bridges and three stinger supported bridges. Crack densities were then determined based on the crack maps corresponding to the surveys for each bridge deck. These crack densities revealed that the structural slab supported bridge decks had a higher propensity for cracking than the bridge decks constructed using stringer supports. Also, since the six bridges surveyed have been constructed within the last two years, a definitive relationship between the age of the bridge and the cracking performance of the bridge deck is not yet evident.