Download or read book Development and Construction of Low cracking High performance Concrete LC HPC Bridge Decks written by and published by . This book was released on 2009 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development and evaluation of low-cracking high-performance concrete (LC-HPC) for use in bridge decks is described based on laboratory test results and experience gained during the construction of 14 bridges. This report emphasizes the material aspects of the construction process; a companion report will provide a detailed discussion of the construction, design, and environmental factors affecting the performance of LC-HPC bridge decks. The KU Mix design methodology for determining an optimized combined gradation uses the percent retained chart and the Modified Coarseness Factor Chart. The process begins by developing an ideal gradation followed by the determination of an optimum blend of user-selected aggregates. A Microsoft® Excel workbook enhanced with Visual Basic for Applications is available to perform the optimization process at www.iri.ku.edu. The second portion of the study involves evaluating the effect of paste content, water-cement (w/c) ratio, coarse aggregate type, mineral admixture type (silica fume, slag cement, and Class F fly ash each at two levels of replacement), cement type and fineness, a shrinkage reducing admixture, and the duration of curing on the free-shrinkage characteristics of concrete mixtures in the laboratory tested in accordance with ASTM C 157. The final portion of the study presents the specifications, construction experiences, and the preliminary evaluation of 14 LC-HPC bridge decks that have been built or are planned in Kansas. The techniques used to reduce cracking in these bridge decks are presented, and the field experiences for the 18 individual LC-HPC placements completed to date are presented. The results indicate that LC-HPC decks with an optimized aggregate gradation and design w/c ratios of 0.44 and 0.45 with cement contents of 317 and 320 kg/m3 (535 and 540 lb/yd3) have more than adequate workability, finishability, and pumpability, in addition to reduced cracking. A preliminary evaluation of these decks indicates that, on average, the LC-HPC decks are performing at a level approximately equal to or exceeding the best performing monolithic decks in Kansas surveyed over the past 15 years.

Download or read book Development and Construction of Low cracking High performance Concrete LC HPC Bridge Decks written by Heather Anne Kirkvold McLeod and published by . This book was released on 2009 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development, construction, and evaluation of Low-Cracking High-Performance Concrete (LC-HPC) bridge decks are described based on laboratory test results and experiences gained through the construction of 14 LC-HPC bridge decks. The study is divided into three parts covering (1) an evaluation of the chloride penetration into concrete using long-term salt-ponding tests, (2) a comprehensive discussion of specifications for LC-HPC construction and standard practices in Kansas, and (3) the description of the construction and the preliminary evaluation of LC-HPC bridge decks in Kansas. This report emphasizes the construction process; a companion report (FHWA-KS-09-5) provided a detailed discussion of the influence of material properties on the performance of LC-HPC bridge decks. The first portion of the study involves evaluating the effect of paste content, curing period, water-cement (w/c) ratio, cement type and fineness, mineral admixtures (ground granulated blast furnace slag and silica fume), a shrinkage reducing admixture (SRA), and standard DOT bridge deck mixtures on chloride penetration into solid concrete, tested in accordance with AASHTO T 259. The evaluation includes a total of 33 individual concrete batches and 123 test specimens. The results indicate that for concrete containing only Portland Cement, reductions in paste content result in increased permeability. A reduced paste content and increased w/c ratio result in increased permeability, whereas the presence of mineral admixtures (ground granulated blast furnace slag and silica fume) and longer curing periods result in decreased permeability. Concrete made with medium or coarse ground Type II cement has greater permeability than concrete made with Type I/II cement. It is not clear how the presence of an SRA affects concrete permeability. LC-HPC mixtures have lower permeability than standard DOT mixtures. The second portion of the study describes the specifications for the LC-HPC and Control bridge decks in Kansas. The focus is on the construction methods, including the evolution of the specifications over time. The third portion of the study details the development and construction of 14 LC-HPC and 12 conventional Control bridge decks built in Kansas. The design details, construction experiences, and lessons learned from the LC-HPC bridge decks are described in detail, and an overview of the materials is presented; the design and construction data for each Control deck is provided; and initial crack survey results are evaluated for various construction-related parameters. The results indicate that successful LC-HPC bridge deck construction is repeatable, and that clear and consistent communication between the contractor, owner, and testing personnel is vital for successful construction of LC-HPC decks. Preliminary evaluation of cracking indicates that at early ages, LC-HPC decks are performing better than the Control decks, as well as earlier monolithic decks in Kansas.

Download or read book Construction of Low cracking High performance Bridge Decks Incorporating New Technology written by James Lafikes and published by . This book was released on 2020 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: Construction and early-age crack evaluations of four bridge decks in Minnesota placed from 2016 to 2018 that incorporate specifications for Internally-Cured Low-Cracking High-Performance Concrete (IC-LC-HPC) are documented in this study. Two additional decks followed specifications for high-performance concrete and served as controls paired with IC-LC-HPC decks. Pre-wetted fine lightweight aggregate (FLWA) was used to provide a targeted internal curing water content of 8% by total weight of binder. The IC-LC-HPC mixtures included 27 to 30% slag cement by total binder weight while the control mixtures included 25 or 35% Class F fly ash by total weight of binder. For one IC-LC-HPC deck, mixture proportions were modified based on a higher FLWA absorption than originally used to design the mixture. One IC-LC-HPC placement failed due to errors in FLWA moisture corrections and concrete batching that led to rejections of batches, leaving an inadequate supply of material to complete the deck. Crack surveys were completed for the IC-LC-HPC and control decks placed in 2016 and 2017. Crack densities at these ages were low compared to most Low-Cracking High-Performance Concrete decks in Kansas and Internally-Cured High-Performance Concrete decks in Indiana. The only exception was one IC-LC-HPC deck that exhibited extensive cracking within one year after placement, which had an overlay with a high cement paste content and no internal curing. This project serves as a foundation for implementing IC-LC-HPC in upcoming bridge decks in Kansas and Minnesota.

Download or read book Construction of Low cracking High performance Bridge Decks Incorporating New Technology Phase II written by Alireza Bahadori and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The construction, crack surveys, and evaluation of 12 bridge decks with internal curing provided by prewetted fine lightweight aggregate and supplementary cementitious materials following internally cured low-cracking high-performance concrete (IC-LC-HPC) specifications of Minnesota or Kansas are described, as well as those from two associated Control decks without IC (MN-Control). Nine IC-LC-HPC decks and one Control deck were monolithic, while three IC-LC-HPC decks and one Control deck had an overlay. The internally cured low-cracking high-performance concrete had paste contents between 23.8 and 25.8 percent by volume. Of the 12 IC-LC-HPC decks, nine were constructed in Minnesota between 2016 and 2020, and three were constructed in Kansas between 2019 and 2021. The performance of the decks is compared with that of earlier IC-LC-HPC bridge decks and low-cracking high-performance concrete (LC-HPC) bridge decks without internal curing. The effects of construction practices on cracking are addressed. The results indicate that the use of overlays on bridge decks is not beneficial in mitigating cracking. The IC-LC-HPC decks constructed exhibited lower average crack densities than those without internal curing. Good construction practices are needed for low-cracking decks. If poor construction practices, which may include poor consolidation and disturbance of concrete after consolidation, over-finishing, delayed application of wet curing, are employed, even decks with low paste contents and internal curing can exhibit high cracking. Delayed curing and over-finishing can also result in scaling damage to bridge decks.

Download or read book Construction of Crack free Bridge Decks written by David Darwin and published by . This book was released on 2017 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: This serves as the final report on Transportation Pooled-Fund Program Project No. TPF-5(174), "Construction of Crack-Free Bridge Decks." The goal of the study was to implement the most cost-effective techniques for improving bridge deck life through the reduction of cracking. Work was performed both in the laboratory and in the field, resulting in the construction of 17 bridge decks in Kansas that were let under Low-Cracking High-Performance Concrete (LC-HPC) specifications. The report documents the performance of the decks based on crack surveys performed on the LC-HPC decks and matching control bridge decks. The specifications for LC-HPC bridge decks, which cover aggregates, concrete, and construction procedures, as well as procedures for performing crack surveys, are summarized. The first 13 LC-HPC bridge decks are compared to control decks in terms of crack density as a function of time. Survey results are also presented for three LC-HPC decks without control decks and one deck let under LC-HPC specifications on which the specifications were not enforced. The widths of measured cracks ranged from 0.006 to 0.025 inches (0.15 to 0.64 mm). The LC-HPC bridge decks exhibit less cracking than the matching control decks in the vast majority of cases. Only bridge decks LC-HPC-2 and LC-HPC-3 have higher overall crack densities than their control decks, the two best performing control decks in the program, and the differences are small. The majority of the cracks are transverse and run parallel to the top layer of the deck reinforcement. Relatively short cracks are present near the abutments and propagate perpendicular to the abutments (longitudinally). The study demonstrates the positive effects of reduced cementitious material and cement paste contents, improved early-age and long-term curing, concrete temperature control, limitations on or de-emphasis of maximum concrete compressive strength, limitations on maximum slump, and minimizing finishing operations on minimizing cracking in 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 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.

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 Documentation of the INDOT Experience and Construction of the Bridge Decks written by Timothy Barrett and published by . This book was released on 2015-09-01 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Indiana Department of Transportation (INDOT) constructed four bridge decks utilizing internally cured, high performance concrete (IC HPC) during the summer of 2013. These decks implement research findings from the research presented in the FHWA/IN/JTRP-2010/10 report where internal curing was proposed as one method to reduce the potential for shrinkage cracking, leading to improved durability. The objective of this research was to document the construction of the four IC HPC bridge decks that were constructed in Indiana during 2013 and quantify the properties and performance of these decks. This report contains documentation of the production and construction of IC HPC concrete for the four bridge decks in this study. In addition, samples of the IC HPC used in construction were compared with a reference high performance concrete (HPC) which did not utilize internal curing. These samples were transported to the laboratory where the mechanical properties, resistance to chloride migration, and potential for shrinkage and cracking was assessed. Using experimental results and mixture proportions, the diffusion based service life of the bridge decks was able to be estimated. Collectively, the results indicate that the IC HPC mixtures that were produced as a part of this study exhibit the potential to more than triple the service life of the typical bridge deck in Indiana while reducing the early age autogenous shrinkage by more than 80% compared to non-internally cured concretes.

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 Concrete Bridge Deck Performance written by H. G. Russell and published by Transportation Research Board. This book was released on 2004 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: At head of title: National Cooperative Highway Research Program.

Download or read book Shrinkage Study of High Performance Concrete for Bridge Decks written by Tengfei Fu and published by . This book was released on 2013 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the field of civil infrastructure, bridge desks are typically constructed using high performance concrete (HPC). Concrete bridge decks demand qualities such as low permeability, high abrasion resistance, superior durability, and long design life. Over decades of field and laboratory experience, many HPC bridge decks have been found to be susceptible to shrinkage and subsequent cracking, which is regarded as a significant cause for premature deterioration, increased maintenance costs and even structural deficiency. Appropriate shrinkage limits and standard laboratory/field tests that allow proper criteria to ensure crack resistant HPC are not clearly established either in the technical literature or in specifications. A comprehensive study is presented in this dissertation on shrinkage and shrinkage induced cracking in HPC, with four main objectives: 1) mitigate the shrinkage and cracking issues in HPC using internal curing by fine lightweight aggregate (FLWA) and/or incorporation of shrinkage reducing admixture (SRA); 2) improve the standard ASTM chemical shrinkage test method for HPC systems containing supplementary cementitious materials (SCMs) and/or SRA; 3) modify existing drying shrinkage models mainly the ACI 209 model to predict long-term drying shrinkage for modern HPC concrete by using short-term experimental measurements; 4) complete a state-of-the-art literature review on shrinkage and cracking issues in HPC bridge decks. One of the most significant research findings is a proposed "cracking potential indicator" (CPI) that uses only the free shrinkage and mechanical properties of HPC. This was correlated to standard restrained ring tests.

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 High performance high strength Lightweight Concrete for Bridge Girders and Decks written by Thomas E. Cousins and published by Transportation Research Board. This book was released on 2013 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: "TRB's National Cooperative Highway Research Program (NCHRP) Report 733: High-Performance/High-Strength Lightweight Concrete for Bridge Girders and Decks presents proposed changes to the American Association of State Highway and Transportation Officials' Load and Resistance Factor Design (LRFD) bridge design and construction specifications to address the use of lightweight concrete in bridge girders and decks. The proposed specifications are designed to help highway agencies evaluate between comparable designs of lightweight and normal weight concrete bridge elements so that an agency's ultimate selection will yield the greatest economic benefit. The attachments contained in the research agency's final report provide elaborations and detail on several aspects of the research. Attachments A and B provide proposed changes to AASHTO LRFD bridge design and bridge construction specifications, respectively; these are included in the print and PDF version of the report. Attachments C through R are available for download below. Attachments C, D, and E contain a detailed literature review, survey results, and a literature summary and the approved work plan, respectively. Attachment C; Attachment D ; Attachment E; Attachments F through M provide details of the experimental program that were not able to be included in the body of this report. Attachment F; Attachment G; Attachment H; Attachment I; Attachment J; Attachment K; Attachment L; Attachment M. Attachments N through Q present design examples of bridges containing lightweight concrete and details of the parametric study. Attachment N; Attachment O; Attachment P; Attachment Q. Attachment R is a detailed reference list."--Publication information.

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 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 Development of High performance Concrete Mixtures for Durable Bridge Decks in Montana Using Locally Available Materials written by John Steven Lawler and published by . This book was released on 2005 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Montana Department of Transportation (MDT) is performing research to develop a cost-effective, indigenous highperformance concrete (HPC) for use in bridge deck applications. The investigation was divided into two tasks: 1) identification of the optimum cementitious matrix for the HPC and 2) evaluation of the performance of this matrix in combination with aggregates readily available in Montana. The work focused on the use of binary, ternary, and quaternary blends of portland cement with fly ash (Class C and F), slag, calcined clay, metakaolin, and silica fume, in combination with Yellowstone River and Western Montana aggregate sources. Testing included plastic properties, setting characteristics, air-void system parameters, electrical conductivity, strength, chloride diffusion, freezing and thawing resistance, scaling resistance, and drying shrinkage. The paper discusses the process required to test and implement HPC specifically for bridge deck applications and presents the test results for this MDT study. The supplementary cementitious material combinations that produced the best performance were silica fume alone, silica fume and slag, Class F fly ash, silica fume and slag-blended cement, and silica fume and calcined clay-blended cement. The importance of raw material testing and the practical reproducibility of the concrete mixture are also considered.