Download or read book Linear Cracking in Bridge Decks written by Soundar S.G Balakumaran and published by . This book was released on 2018 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete cracking in bridge decks remains an important issue relative to deck durability. Cracks can allow increased penetration of chlorides, which can result in premature corrosion of the reinforcing steel and subsequent spalling of the concrete deck. Although it is understood that the service life of bridge decks is affected by concrete cracking, the degree to which cracking affects service life is unknown. Crack repairs may be expensive, and only a few state transportation agencies have developed effective decision-making tools to support engineering decisions about whether and how to repair cracks in bridges. To understand how various factors affect the formation of cracks and to comprehend how cracks influence the performance of bridge decks, a comprehensive literature review was performed of publications from the early 1970s to the present. With findings from more than 45 years of research, the influences of about 30 factors were included in the literature review. In this study, 37 highway bridges in Virginia were selected on the basis of environmental exposure, geographic location, traffic conditions, and construction era. Ten decks with ordinary portland cement (OPC) concrete with a water–cementitious material (w/c) ratio of 0.47 with uncoated reinforcement were built from 1968 through 1971, and 27 decks with concrete with a w/c ratio of 0.45 with epoxy-coated reinforcement were built from 1984 through 1991. Of the newer 27 decks, 11 had concrete with supplementary cementitious material (SCM) such as fly ash and slag. The study included field surveys, sampling, and extensive data collection with regard to the decks. In addition, a laboratory study of the collected samples was conducted to understand the material properties and to determine the chloride contents. Statistical methods were used to analyze the collected data and to form regression models for prediction of crack influence on chloride diffusion. The increase in chloride diffusion through cracks when compared to that of corresponding uncracked locations was statistically significant. No strong correlation was found between surface crack width and chloride diffusion; however, a significant correlation was found between crack depth and chloride diffusion. To understand the effects of cracks on the durability of the structures, service life was estimated using a probabilistic chloride diffusion model based on Fick’s second law of diffusion. The estimated service life of the decks with concrete with SCM was around 100 years but only if no cracks were present. The presence of cracks affected the service life significantly. With higher crack frequencies, the service life plunged to the levels of decks built with OPC concrete, which was significantly lower to begin with. The service life of decks built with OPC concrete was not significantly affected by the presence of cracks, primarily because the high permeability of OPC concrete, with or without the presence of cracks, results in a shorter service life for OPC concrete decks. Time to corrosion initiation for corrosion-resistant reinforcing bars, ASTM A1035 (VDOT Class I reinforcement) and ASTM A955 (VDOT Class III reinforcement), was estimated, and the service lives were much longer compared to those of the decks in this study constructed with other types of reinforcement. Implementation guidance for quality assurance of newly built bridge decks with modern concrete mixtures and corrosion-resistant reinforcement and for maintenance of existing bridge decks was developed based on the study results.

Download or read book The Effect of Linear Cracking on Chloride Penetration in Concrete Bridge Decks written by Jacqueline M. Sansone and published by . This book was released on 2006 with total page 410 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 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 Control and Repair of Bridge Deck Cracking written by Robert J. Frosch and published by . This book was released on 2010-11-15 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cracking in Bridge Decks written by Pui-shum B. Shing and published by . This book was released on 1999 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the findings of a study whose primary objectives are to determine the cause of extensive transverse cracking that has been observed in some existing bridge decks, and to identify the change of material specifications and construction practice that is necessary to reduce the severity of deck cracking. To achieve these goals, recent studies on the cause of bridge deck cracking were reviewed, an experimental study was conducted to compare the shrinkage properties of different concrete mixes, and the current material and design specifications and construction practice adopted by the Colorado Department of Transportation (CDOT) were reviewed to identify areas that need improvement. A survey was conducted on seven newly constructed bridges to examine the extent of cracking in concrete decks that were constructed with the different mix designs and curing procedure that were currently used by CDOT.

Download or read book Quantification of Cracks in Reinforced Concrete Bridge Decks written by Saikrishna Ganapuram and published by . This book was released on 2013 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cracking in reinforced concrete bridge decks is a widespread concern in the United States. Many concrete bridge decks, regardless to the age of construction, have shown different levels and patterns of cracking. Not only does cracking of bridge decks weaken the bridge infrastructure, but also allows the inflow of corrosive agents into the reinforcement, regardless of the bridge design type, length of spans, deck thickness and concrete mixture designs. Increased cracking of concrete bridge decks all over the world poses a threat to life as well as prove extremely expensive for repair and maintenance. Thus, precautions must be taken in order to avoid and restrict bridge deck cracking, one of which is inspection of the bridge at regular intervals. The Ohio Department of Transportation's current procedure for bridge inspection offers only a qualitative assessment of the bridges inspected. In this study, a method was developed for the quantification of crack densities for twelve bridges in District 3. Two types of bridges were inspected: three structural slab bridge decks and nine stringer supported bridge decks. Crack densities for each bridge were determined based on crack maps corresponding to the surveys for each bridge deck. Results indicated that structural slab bridge decks have slightly higher shrinkage crack densities compared to the bridge decks constructed with stringer supports. However, the "structural" cracks seem to be wider than shrinkage cracks for structural slabs (greater than 0.007 inch). Particularly on bridge ASD-42-0656, which is a continuous slab bridge, there were several large "structural" cracks that were parallel to the pier beams supports. The shrinkage crack densities of the twelve bridge decks determined in this study were considerably lower than the crack densities of similar bridge decks located in other states, demonstrating that Ohio bridge decks in general have lower crack density than those in other states. The shrinkage crack densities of the bridges constructed with QC/QA type of concrete have lower values than the bridges made with other types of concrete. Also, the crack widths were determined at certain key locations and were compared with theoretical values. The measured crack widths are much larger compared to the corresponding theoretical crack widths. This is a reason for concern.

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 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 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 Control of Cracking in Bridge Decks written by D. Darwin and published by . This book was released on 2004 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crack surveys of bridge decks, performed over a 10-year period in northeast Kansas as part of three studies, provide strong guidance in identifying the parameters that control cracking in these structures. The surveys involve steel girder bridges--bridges that are generally agreed to exhibit the greatest amount of cracking in the concrete decks. The surveys include monolithic decks and decks with silica fume and conventional concrete overlays. The study demonstrates that crack density increases as a function of cement and water content, and concrete strength. In addition, crack density is higher in the end spans of decks that are integral with the abutments than decks with pin-ended supports. Most cracking occurs early in the life of a bridge deck, but continues to increase over time. This is true for bridges cast in both the 1980s and the 1990s. A key observation, however, is that bridge decks cast in the 1980s exhibit less cracking than those in the 1990s, even with the increase in crack density over time. Changes in materials, primarily cement fineness, and construction procedures over the past 20 years, are discussed in light of these observations. A major bright spot has been the positive effect of efforts to limit early evaporation, suggesting that the early initiation of curing procedures will help reduce cracking in bridge decks.

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 Sealing of Cracks on Florida Bridge Decks with Steel Girders written by Adel ElSafty and published by . This book was released on 2012 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the biggest problems affecting bridges is the transverse cracking and deterioration of concrete bridge decks. This research identifies suitable sealing materials for deck cracks showing their ability to span cracks of various widths and achieving performance criteria such as penetration depth, bond strength to crack walls, elongation, viscosity, penetration, and suitability of the type of sealant. Sealant performance was investigated by testing core samples to determine the depth of sealant penetration, bond, and tensile strength. Sealer samples were tested to verify their strength, modulus of elasticity, and elongation. A finite element model was developed to investigate the factors affecting tensile stresses and crack tendency. It also checks the live-load deflection limit, which is an important factor in bridge deck cracking. An Excel spreadsheet was also developed to predict the deck cracking accounting for shrinkage, thermal effect, creep, concrete mix design, deck restraint, loading, and environmental effects.

Download or read book Cracking Behavior of Structural Slab Bridge Decks written by Anil Patnaik and published by . This book was released on 2014 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridge deck cracking is a common problem throughout the United States, and it affects the durability and service life of concrete bridges. Several departments of transportation (DOTs) in the United States prefer using continuous three-span solid structural slab bridges without stringers over typical four-lane highways. Recent inspections of such bridges in Ohio revealed cracks as wide as 0.125 in. These measured crack widths are more than ten times the maximum limit recommended in ACI 224R-01 for bridge decks exposed to de-icing salts. Measurements using digital image correlation revealed that the cracks widened under truck loading, and in some cases, the cracks did not fully close after unloading. This dissertation includes details of an experimental investigation of the cracking behavior of structural concrete. Prism tests revealed that the concrete with epoxy-coated bars (ECB) develops the first crack at smaller loads, and develops larger crack widths compared to the corresponding specimens with uncoated (black) bars. Slab tests revealed that the slabs with longitudinal ECB developed first crack at smaller loads, exhibited wider cracks and a larger number of cracks, and failed at smaller ultimate loads compared to the corresponding test slabs with black bars. To develop a preventive measure, slabs with basalt and polypropylene fiber reinforced concrete were also included in the test program. These test slabs exhibited higher cracking loads, smaller crack widths, and higher ultimate loads at failure compared to the corresponding slab specimens without fibers. Merely satisfying the reinforcement spacing requirements given in AASHTO or ACI 318-11 is not adequate to limit cracking below the ACI 224R-01 recommended maximum limit, even though all the relevant design requirements are otherwise met. Addition of fiber to concrete without changing any steel reinforcing details is expected to reduce the severity and extent of cracking in reinforced concrete bridge decks.

Download or read book Transverse Cracking in Bridge Decks written by Laurice Jean Eppers and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Investigation of Cracking in Concrete Bridge Decks at Early Stages written by Stanislav Milos Dekic and published by . This book was released on 1996 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: