Download or read book Material Properties and Corrosion Condition of a Twenty year old Prestressed Bridge Girder written by Florie B. Coggins and published by . This book was released on 1992 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Material Properties of a Twenty year old Prestressed Bridge Girder Obtained by Nondestructive Testing written by Florie Bustamante Coggins and published by . This book was released on 1989 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Highway Research Abstracts written by and published by . This book was released on 1994 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Flexural and Shear Response of Deteriorated Prestressed Concrete Girders Taken from a Decommissioned Bridge in Alberta written by Zhaohan Wu and published by . This book was released on 2021 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prestressed concrete (PC) bridges are a major component of North America's transportation network. As this network ages, the response of deteriorated PC bridge girders is of interest since rehabilitation and repairs are constrained by limited infrastructure budgets. Bridges are often evaluated using a largely qualitative rating system which results in differences in opinions between evaluators. As part of a larger initiative to develop reliability-based bridge management tools for deteriorated structures, this thesis presents results and analysis from a series of full-scale destructive tests on a 28-year old PC bridge removed from service near Barrhead, Alberta. There are many studies on PC girders, but these studies are limited to non-deteriorated systems, systems with accelerated deterioration (corrosion, debonding), non-destructive testing, and normal density concrete. The impact of deterioration on semi-lightweight PC girders subject to real-world environmental effects is rarely studied. Destructive testing was carried out on four 11 m single span, semi-lightweight PC voided slab girders taken from a decommissioned bridge with different types and degrees of deterioration. Both flexural and shear testing was conducted to provide insight on the deteriorated behaviour of the girders. Four-point bending was used for flexural test. Shear tests were conducted using three-point bending with different shear spans (1.0 m and 1.5 m). Modifications on some girders simulated further damage. Flexure tests indicated that all girders resisted the design factored load based on CSA S6:19 but no girders satisfied live load deflection limits of span/800. Deterioration significantly affected the flexural strength of the girders with a 23% decrease in strength for the most deteriorated girder relative to the baseline girder. More concerning, corrosion led to undesirable strand rupture failure prior to yielding which greatly reduced failure deflection. Material tests confirmed that strand corrosion greatly affected the strength and ductility of the strands. Shear tests showed that shear span-to-depth ratio affected failure mode. All specimens with 1.0 m load scheme failed by strut crushing. For 1.5 m load scheme, girders in fair condition failed by shear compression. However, when stirrups were corroded, diagonal tension failure occurred leading to excessive yielding and wide cracks. Anchorage failure may occur when anchorage is inadequate leading to sudden failure from reinforcement or strand pull out. All girders performed well above design ULS loadings; deterioration did not greatly impact the peak load for the tested girders. However, deterioration affected events leading up to failure. Struts formed at a 29% lower load for 1.0 m load scheme and 32% lower load for 1.5 m load scheme due to induced prestressed strand loss, but the ultimate load only decreased by 9.6% and 9.9% for 1.0 and 1.5 m respectively. Anchorage failure resulted in the lowest peak load and sudden unexpected failure away from load point. Corrosion that leads to anchorage issues, such as end cracking, needs to be carefully examined by bridge inspectors. After testing, forensic investigation found the average as-built concrete strength was 51% larger than the design value; four extra 25M bars were also discovered that were not included in the stock drawings for this bridge. These bars were initially added for camber control but served as a major backup system since corrosion was much more present in the strands. With updated material properties, CSA S6:19 accurately predicted the baseline girder capacity within 5% of the test value for flexure. CSA S6:19's sectional approach based on MCFT was conservative in predicting the shear capacity of the girders for both load schemes due to the assumption of plane sections remaining plane. Considering both flexural and shear results, it was concluded that the deteriorated PC girders were flexure dominant and safely resisted the design load at the time of testing.

Download or read book Proceedings written by and published by . This book was released on 1990 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Annual Index written by and published by . This book was released on 1993 with total page 1836 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ACI Materials Journal written by and published by . This book was released on 1995 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Behavior of Concrete Girders Prestressed with Stainless Steel Strands written by Anwer Al-Kaimakchi and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prestressed concrete is used in structures because of its versatility, adaptability, and durability. Durability of prestressed concrete bridges in extremely aggressive environments is of increasing concern because of corrosion of the carbon steel strands that are typically used for prestressing. Concrete is a permeable material where chloride ions can penetrate through and reach the internal reinforcement and carbon steel strands are highly susceptible to corrosion. Thus, prestressed concrete bridges located in areas with high exposure to environmental factors (e.g., marine environments) deteriorate due to corrosion of carbon steel strands. For example, Florida has a long coastline, with many concrete bridges over coastal water. Among the 12,518 bridges in Florida, 6,303 are prestressed concrete, and almost half of them are older than 40 years. One solution to overcome the early deterioration of coastal bridges is to use corrosion-resistant strands, such as Duplex High-Strength Stainless Steel (HSSS) strands.HSSS strands have high corrosion resistance and are an alternative to carbon steel strands in concrete bridges in extremely aggressive environments. The growing interest in using stainless steel strands has led to the development of the ASTM A1114. In 2020, ASTM A1114 was released as a standard specification for low-relaxation, seven-wire, Grade 240, stainless steel strands for prestressed concrete. Stainless steel is made from different alloys compared to carbon steel, and thus the mechanical properties of stainless steel strands are fundamentally different than those of carbon steel strands. The most significant difference is in the guaranteed ultimate strain: the value for stainless steel strands is only 1.4%. Several departments of transportation (DOTs) have already used or allowed the use of HSSS strands in prestressed piles. As of 2020, a total of 17 projects have used stainless steel strands, a majority of them in piles. Those projects are in areas with high exposure to environmental factors. The use of HSSS strands in flexural members has been hindered by the lack of full-scale test results, structural design approaches, and/or design guidelines. The main concern in using HSSS strands in flexural members is their low ductility. Concrete members prestressed with HSSS strands, if not properly designed, might fail suddenly without adequate warning. There have been no attempts to address this problem in full-scale research studies. The goals of this research project were to investigate the use of HSSS strands in flexural members and to develop design guidelines that could be used by bridge engineers. A total of thirteen (13) 42-ft-long AASHTO Type II girders were designed, fabricated, and tested in flexure or shear. Ten (10) girders were prestressed with HSSS strands, while the other three (3) were prestressed with carbon steel strands and served as control girders. This research program included experimental activities to determine the mechanical and bond strength characteristics, prestress losses, and transfer length of 0.6-in-diameter HSSS strands. Twenty HSSS strands from two spools were tested in direct tension. A stress-strain equation is proposed for the 0.6-in.-diameter HSSS strands, which satisfied all ASTM A1114 requirements. The minimum and average bond strengths, following ASTM A1081, of six 0.6-in.-diameter HSSS strands were 15.8 kips and 17.9 kips, respectively. The minimum and average experimental ASTM A1081 bond strengths were 23.4% and 19.8% greater than the recommended values by PCI Strand Bond Task Group. The maximum measured transfer length of 0.6-in.-diameter HSSS strands was 21.5 inches, which was less than the value predicted by AASHTO LRFD Bridge Design Specifications' equation for carbon steel strands. Experimental flexural and shear results showed that the post-cracking behavior of girders prestressed with HSSS strands continued to increase up to failure with no discernible plateau. The behavior is attributed to the stress-strain behavior of the HSSS strands. Also, flexural results revealed that, although HSSS strands have low ductility and all composite girders failed due to rupture of strands, the girders exhibited large reserve deflection and strength beyond the cracking load and provided significant and substantial warning through large deflection, as well as well-distributed and extensive flexural cracking, before failure. A non-linear analytical model and an iterative numerical model were developed to predict the flexural behavior of concrete members prestressed with HSSS strands. Although the analytical model gave better predictions, the iterative numerical approach is slightly conservative and is easier to use for design - designers prefer to use an equation type of approach to perform preliminary designs. Numerical equations were developed to calculate the nominal flexural resistance for flexural members prestressed with HSSS strands. The proposed equations are only valid for rectangular sections. In the case of flanged sections, iterative numerical approaches were also introduced. Because HSSS strand is a brittle material, the design must consider the strain capacity of the strand and must be balanced between flexural strength and ductility. Based on the flexural design philosophy for using carbon steel strands in prestressed concrete girders, along with experimentally-observed behaviors and analytical results for concrete members prestressed with HSSS strands, flexural design guidelines were developed for the use of HSSS strands in flexural members. For I-girders, rupture of strands failure mode is recommended by assuring that concrete in the extreme compression fiber reaches considerable inelastic stresses, at least 0.7f_c^'. For slab beams (e.g. Florida Slab Beam), crushing of concrete failure mode is recommended by assuring that the net tensile strain in the HSSS strand is greater than 0.005. The recommended maximum allowable jacking stress and stress immediately prior to transfer are 75% and 70%, respectively. A resistance factor of 0.75 is recommended for both rupture of strand and crushing of concrete failure modes. AASHTO equations conservatively estimated the measured transfer length and prestress losses of 0.6-inches-diameter HSSS strands. The ACI 318-19 and AASHTO LRFD conservatively predicted the shear capacity of concrete girders prestressed with HSSS strands.

Download or read book Prestress Losses in Pretensioned High strength Concrete Bridge Girders written by Maher K. Tadros and published by Transportation Research Board. This book was released on 2003 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The HCM includes three printed volumes (Volumes 1-3) that can be purchased from the Transportation Research Board in print and electronic formats. Volume 4 is a free online resource that supports the rest of the manual. It includes: Supplemental chapters 25-38, providing additional details of the methodologies described in the Volume 1-3 chapters, example problems, and other resources; A technical reference library providing access to a significant portion of the research supporting HCM methods; Two applications guides demonstrating how the HCM can be applied to planning-level analysis and a variety of traffic operations applications; Interpretations, updates, and errata for the HCM (as they are developed);A discussion forum allowing HCM users to ask questions and collaborate on HCM-related matters; and Notifications of chapter updates, active discussions, and more via an optional e-mail notification feature."--Publisher.

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 Government Reports Announcements Index written by and published by . This book was released on 1993-12 with total page 1576 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Corrosion protection of prestressing steels written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 1996-09-01 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Checklist of State Publications written by Library of Congress. Exchange and Gift Division and published by . This book was released on 1994 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt: June and Dec. issues contain listings of periodicals.

Download or read book Prestressed Concrete Bridges written by Christian Menn and published by Birkhäuser. This book was released on 2012-12-06 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book was written to make the material presented in my book, Stahlbetonbrucken, accessible to a larger number of engineers throughout the world. A work in English, the logical choice for this task, had been contemplated as Stahlbetonbrucken was still in its earliest stages of preparation. The early success of Stahlbetonbrucken provided significant impetus for the writing of Prestressed Concrete Bridges, which began soon after the publication of its predecessor. The present work is more than a mere translation of Stahlbetonbrucken. Errors in Stahlbetonbrucken that were detected after publication have been corrected. New material on the relation between cracking in concrete and corrosion of reinforce ment, prestressing with unbonded tendons, skew-girder bridges, and cable-stayed bridges has been added. Most importantly, however, the presentation of the material has been extensively reworked to improve clarity and consistency. Prestressed Concrete Bridges can thus be regarded as a thoroughly new and improved edition of its predecessor.

Download or read book Futures in Mechanics of Structures and Materials written by Thiru Aravinthan and published by CRC Press. This book was released on 2008-11-20 with total page 915 pages. Available in PDF, EPUB and Kindle. Book excerpt: Futures in Mechanics of Structures and Materials is a collection of peer-reviewed papers presented at the 20th Australasian Conference on the Mechanics of Structures and Materials (ACMSM20, University of Southern Queensland, Toowoomba, Queensland, Australia, 2 - 5 December 2008) by academics, researchers and practicing engineers mainly from Austral

Download or read book Dauerhaftigkeit Von Bauwerken written by and published by . This book was released on 1989 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Cost of Corrosion in China written by Baorong Hou and published by Springer Nature. This book was released on 2019-09-26 with total page 953 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprehensively covers corrosion and corrosion protection in China in the areas including infrastructure, transportation, energy, water environment, as well as manufacturing and public utilities. Furthermore, it presents a major consulting project of Chinese Academy of Engineering, which was the largest corrosion investigation project in Chinese history, including the corresponding methods, processes and corrosion protection strategies, and provides valuable information for numerous industries. Sharing essential insights into corrosion prediction and decision-making, this book will help to decrease costs and extend the service life of equipment and facilities; accordingly, it will benefit scientists and engineers working on corrosion research and protection, as well as economists and government employees.