Download or read book Identification of Causes and Solution Strategies for Deck Cracking in Jointless Bridges written by David J. Stringer and published by . This book was released on 2012 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridges have traditionally relied on a system of expansion joints and flexible bearings to accommodate movements due to temperature, creep, and shrinkage loading. Joints and elements in their vicinity experience a high amount of degradation; thus modern design approaches are advocating their removal, with movement accommodated through flexible piles and abutment walls. While jointless bridges have been performing well, many of them suffer from widespread early-age transverse deck cracking. Restrained concrete shrinkage was identified as the most dominant source for the noted damage based on a literature review and a field investigation. Deck cracking is caused by the build-up of tensile forces resulting from the increased rigidity in jointless bridges. Experimentally calibrated finite-element models were used to predict deck cracking in two bridge systems under shrinkage-induced loading and a parametric study was conducted to investigate the influence of design parameters on restrained shrinkage cracking. Simulation results confirmed that the increase of system restraint increases the tendency for cracking. Models for steel and concrete beam bridges showed that both systems were equally susceptible to deck cracking due to restrained concrete shrinkage. The lowest amount of cracking was predicted for bridges with non-integral abutments, higher shear connector spacing, and a low-shrinkage concrete mix. Changing the deck reinforcement configuration had little effect on the predicted damage patterns. Use of a low-shrinkage concrete mix had the greatest impact on minimizing deck cracking. Overall, the computational simulations indicated that restrained shrinkage cracking in the decks of jointless bridges is unavoidable, but that modifying design details and improving concrete mixture designs can help reduce its extent.
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 Mitigation Strategies for Early age Shrinkage Cracking in Bridge Decks written by Pizhong Qiao (Civil engineer) and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Early-age shrinkage cracking has been observed in many concrete bridge decks in Washington State and elsewhere around the U.S. The cracking increases the effects of freeze-thaw damage, spalling, and corrosion of steel reinforcement, thus resulting in premature deterioration and structural deficiency of the bridges. In this study, the main causes of the early-age cracking in the decks are identified, and concrete mix designs as a strategy to prevent or minimize the shrinkage cracking are evaluated. Different sources (eastern and western Washington) and sizes of aggregates are considered, and the effects of paste content, cementitious materials (cement, fly ash, silica fume, slag), and shrinkage reducing admixture (SRA) are evaluated. A series of fresh, mechanical and shrinkage property tests were performed for each concrete mix. The outcomes of this study identify optimum concrete mix designs as appropriate mitigation strategies to reduce or eliminate early-age shrinkage cracking and thus help minimize shrinkage cracking in the concrete bridge decks, potentially leading to longer service life.
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 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 Determination of the Causes of Cracking in a Bridge Deck written by Howard Newlon and published by . This book was released on 1963 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mitigation Strategies for Early age Shrinkage Cracking in Bridge Decks written by Pizhong Qiao and published by . This book was released on 2010 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: Early-age shrinkage cracking has been observed in many concrete bridge decks in Washington State and elsewhere around the U.S. The cracking increases the effects of freeze-thaw damage, spalling, and corrosion of steel reinforcement, thus resulting in premature deterioration and structural deficiency of the bridges. In this study, the main causes of the early-age cracking in the decks are identified, and concrete mix designs as a strategy to prevent or minimize the shrinkage cracking are evaluated. Different sources (eastern and western Washington) and sizes of aggregates are considered, and the effects of paste content, cementitious materials (cement, fly ash, silica fume, slag), and shrinkage reducing admixture (SRA) are evaluated. A series of fresh, mechanical and shrinkage property tests were performed for each concrete mix. The outcomes of this study identify optimum concrete mix designs as appropriate mitigation strategies to reduce or eliminate early-age shrinkage cracking and thus help minimize shrinkage cracking in the concrete bridge decks, potentially leading to longer service life.
Download or read book Final Report on Field Demonstration of Durable Link Slabs for Jointless Bridge Decks Based on Strain hardening Cementitious Composites written by Victor C. Li and published by . This book was released on 2008 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research is on the development of durable link slabs for jointless bridge decks based on strain-hardening cementitious composite - engineered cementitious composite (ECC). Specifically the superior ductility of ECC was utilized to accommodate bridge deck deformations imposed by girder deflection, concrete shrinkage, and temperature variations, providing a cost-effective solution to a number of deterioration problems associated with bridge deck joints. In this phase 3, research was initiated at developing a solution for early age cracking observed on the Grove Street Bridge ECC link-slab. Systematic investigations (both numerical and experimental) have been conducted on identifying factors which cause early age cracking, replicating early age cracking behavior observed in the field, developing new ECC materials solution to prevent early age cracking, documenting new ECC fresh and hardened properties, verifying new ECC performance by means of the large frame restrained shrinkage test, and revising special provision of ECC link slab. Grove Street Bridge was monitored constantly over the whole project period.
Download or read book Effects of Design Parameters on Deck Cracking from Restrained Concrete Shrinkage in Jointless Bridges written by David Jonathan Stringer and published by . This book was released on 2012 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bridge Bearings and Expansion Joints written by D J Lee and published by CRC Press. This book was released on 1994-11-03 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a guide to movement and restraint in bridges for bridge engineers and will enable them to draw up design calculations and specifications for effective installation, and satisfactory service and durability of bearings and joints. It has been fully revised and updated in line with current codes and design practice, modern developme
Download or read book Expansion Joints in Buildings written by National Research Council and published by National Academies Press. This book was released on 1974-02-01 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many factors affect the amount of temperature-induced movement that occurs in a building and the extent to which this movement can occur before serious damage develops or extensive maintenance is required. In some cases joints are being omitted where they are needed, creating a risk of structural failures or causing unnecessary operations and maintenance costs. In other cases, expansion joints are being used where they are not required, increasing the initial cost of construction and creating space utilization problems. As of 1974, there were no nationally acceptable procedures for precise determination of the size and the location of expansion joints in buildings. Most designers and federal construction agencies individually adopted and developed guidelines based on experience and rough calculations leading to significant differences in the various guidelines used for locating and sizing expansion joints. In response to this complex problem, Expansion Joints in Buildings: Technical Report No. 65 provides federal agencies with practical procedures for evaluating the need for through-building expansion joints in structural framing systems. The report offers guidelines and criteria to standardize the practice of expansion joints in buildings and decrease problems associated with the misuse of expansions joints. Expansions Joints in Buildings: Technical Report No. 65 also makes notable recommendations concerning expansion, isolation, joints, and the manner in which they permit separate segments of the structural frame to expand and to contract in response to temperature fluctuations without adversely affecting the buildings structural integrity or serviceability.
Download or read book LRFD Guide Specifications for the Design of Pedestrian Bridges written by American Association of State Highway and Transportation Officials and published by AASHTO. This book was released on 2009 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fibre Optic Methods for Structural Health Monitoring written by Branko Glisic and published by John Wiley & Sons. This book was released on 2008-03-11 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of fibre optic sensors in structural health monitoring has rapidly accelerated in recent years. By embedding fibre optic sensors in structures (e.g. buildings, bridges and pipelines) it is possible to obtain real time data on structural changes such as stress or strain. Engineers use monitoring data to detect deviations from a structure’s original design performance in order to optimise the operation, repair and maintenance of a structure over time. Fibre Optic Methods for Structural Health Monitoring is organised as a step-by-step guide to implementing a monitoring system and includes examples of common structures and their most-frequently monitored parameters. This book: presents a universal method for static structural health monitoring, using a technique with proven effectiveness in hundreds of applications worldwide; discusses a variety of different structures including buildings, bridges, dams, tunnels and pipelines; features case studies which describe common problems and offer solutions to those problems; provides advice on establishing mechanical parameters to monitor (including deformations, rotations and displacements) and on placing sensors to achieve monitoring objectives; identifies methods for interpreting data according to construction material and shows how to apply numerical concepts and formulae to data in order to inform decision making. Fibre Optic Methods for Structural Health Monitoring is an invaluable reference for practising engineers in the fields of civil, structural and geotechnical engineering. It will also be of interest to academics and undergraduate/graduate students studying civil and structural engineering.
Download or read book Model Code for Service Life Design written by fib Fédération internationale du béton and published by fib Fédération internationale du béton. This book was released on 2006-01-01 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: fib Bulletin 34 addresses Service Life Design (SLD) for plain concrete, reinforced concrete and pre-stressed concrete structures, with a special focus on design provisions for managing the adverse effects of degradation. Its objective is to identify agreed durability related models and to prepare the framework for standardization of performance based design approaches. Four different options for SLD are given: - a full probabilistic approach, - a semi probabilistic approach (partial factor design), - deemed to satisfy rules, - avoidance of deterioration. The service life design approaches described in this document may be applied for the design of new structures, for updating the service life design if the structure exists and real material properties and/or the interaction of environment and structure can be measured (real concrete covers, carbonation depths), and for calculating residual service life. The bulletin is divided into five chapters: 1. General 2. Basis of design 3. Verification of Service Life Design 4. Execution and its quality management 5. Maintenance and condition control It also includes four informative annexes, which give background information and examples of procedures and deterioration models for the application in SLD. The format of Bulletin 34 follows the CEB-FIP tradition for Model Codes: the main provisions are given on the right-hand side of the page, and on the left-hand side, the comments. Note: An Italian translation of Bulletin 34 is also available; contact us for further details.
Download or read book Settlement of Bridge Approaches written by Jean-Louis Briaud and published by Transportation Research Board. This book was released on 1997 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Long Term Behavior of Integral Abutment Bridges written by Robert J. Frosch and published by Joint Transportation Research Program. This book was released on 2011-08-15 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integral abutment (IA) construction has become the preferred method over conventional construction for use with typical highway bridges. However, the use of these structures is limited due to state mandated length and skew limitations. To expand their applicability, studies were implemented to define limitations supported by rational analysis rather than simply engineering judgment. Previous research investigations have resulted in larger length limits and an overall better understanding of these structures. However, questions still remain regarding IA behavior; specifically questions regarding long-term behavior and effects of skew. To better define the behavior of these structures, a study was implemented to specifically investigate the long term behavior of IA bridges. First, a field monitoring program was implemented to observe and understand the in-service behavior of three integral abutment bridges. The results of the field investigation were used to develop and calibrate analytical models that adequately capture the long-term behavior. Second, a single-span, quarter-scale integral abutment bridge was constructed and tested to provide insight on the behavior of highly skewed structures. From the acquired knowledge from both the field and laboratory investigations, a parametric analysis was conducted to characterize the effects of a broad range of parameters on the behavior of integral abutment bridges. This study develops an improved understanding of the overall behavior of IA bridges. Based on the results of this study, modified length and skew limitations for integral abutment bridge are proposed. In addition, modeling recommendations and guidelines have been developed to aid designers and facilitate the increased use of integral abutment bridges.
Download or read book AASHTO Guide for Commonly Recognized CoRe Structural Elements written by American Association of State Highway and Transportation Officials. Subcommittee on Bridges and Structures of the Standing Committee of Highways and published by American Association of State Highway & Transportation Officials. This book was released on 1997 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This guide provides a description of structural elements that are commonly used in highway bridge construction and encountered on bridge safety inspections."--Introduction (Page 1).
