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 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 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 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 Early Age Shrinkage and Cracking of Nevada Concrete Bridge Decks written by Heinere Howard Ah-Sha and published by . This book was released on 2001 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Field Monitoring of Shrinkage Cracking Potential in a High performance Bridge Deck written by Timothy Walkowich and published by . This book was released on 2011 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past decade many state engineers throughout New Jersey have reported cracking on High Performance Concrete (HPC) bridge decks at early ages. The presence of cracking early in the life of a high performance deck offsets the benefits gained in using the material as the potential for corrosion begins at the onset of cracking. While many factors apply to bridge deck cracking, the shrinkage of the concrete's mass is a primary concern. Because of shear studs and boundary conditions, among other causes that act in restraining the deck itself, it is important to understand the mechanics of concrete under restraint. The AASHTO Passive Ring Test (PP 34-06) is seeing an increase in use in studies analyzing restrained shrinkage. The test simulates a concrete member of infinite length and allows researchers to study the effects of various parameters on restrained shrinkage. This thesis presents the results of a study that analyzed the ring test's ability to simulate restrained shrinkage on HPC bridge decks. The investigation incorporated an instrumented, simply supported composite bridge deck with laboratory samples taken on the day of the pour as well as a finite element analysis. The results suggest the AASHTO Passive Ring Test simulates the restrained shrinkage of simply supported HPC decks reasonably well. Fewer than 1% of all cracking present on the ring specimens saw complete penetration through the sample with 80-90% of all cracking considered to be micro cracking. While the presence of several cracks along the bridge deck itself showed no correlation with the shrinkage ring specimens, finite element analysis suggests these cracks are a result of adjacent live load. Also, the findings of this study highlight the importance of following design in the field as well as the effect of live load on staged construction of HPC bridge decks.

Download or read book Early age Cracking Control on Modern Concrete written by Dejian Shen and published by Springer Nature. This book was released on with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Control of Concrete Cracking in Bridges written by and published by . This book was released on 2017 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Tool for Analysis of Early Age Transverse Cracking of Composite Bridge Decks written by Levon Minnetyan and published by . This book was released on 2011 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research project investigated stresses in high performance (HP) concrete composite bridge decks due to temperature, shrinkage, and vehicle loading. Computational methods and software were developed to compute the stresses. The structural analysis program used a layered finite element model. Time-history residual stresses were computed for 28 days, then an HS25 vehicle load was applied. Longitudinal stress levels were printed layer by layer for comparison with the modulus of rupture and assessment of cracking.

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 Control of Time dependent Transverse Cracking in Reinforced Concrete Bridge Decks written by Cathy Hsiang-Chen Chen 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 Investigation of Cracking in High Performance Concrete Used in New York State Bridge Decks written by Mohammad Hadi Kazemi Kamyab and published by . This book was released on 2008 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Performance Concrete Bridge Decks A Fast Track Implementation Study Volume 2 Materials written by Mateusz Radlinski and published by Purdue University Press. This book was released on 2008-11-01 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this research was to examine the applicability of ternary binder systems containing ordinary portland cement (OPC), class C fly ash (FA) and silica fume (SF) for bridge deck concrete. This was accomplished in two parts, the laboratory part and a field application part. During the laboratory studies, four ternary mixtures, each containing either 20% or 30% FA and either 5% or 7% SF were subjected to four different curing regimes (air drying, 7 days curing compound application and 3 or 7 days wet burlap curing). In general, all four ternary mixtures exhibited very good water and chloride solution transport-controlling properties (resistance to chloride-ion penetration, chloride diffusivity and rate of water absorption). However, it was concluded that in order to ensure adequate strength, good freezing and thawing resistance, satisfactory resistance to salt scaling, and adequate shrinkage cracking resistance the FA content should not exceed 20%, SF content should not exceed 5% (by total mass of binder) and paste content should be kept below 24% by volume of concrete. Further, wet burlap curing for a minimum of 3 days was required to achieve satisfactory performance and to obtain a reliable assessment of in-situ compressive strength (up to 28 days) using maturity method. The second part of this research examined the performance of ternary concrete containing 20% FA and 5% SF in the pilot HPC bridge deck constructed in northern Indiana. Using maturity method developed for the purpose of this study, it was determined that the unexpectedly high RCP values of concrete placed late in the construction season were mostly attributed to low ambient temperature. Additional applications of the developed maturity method were also demonstrated. These include assessment of risk of scaling and reduction in time to corrosion initiation as a function of construction date, as well as estimation of long-term RCP values of concrete subjected to accelerated curing.