Concrete Bridges In Aggressive Environments
DOWNLOAD
Download Concrete Bridges In Aggressive Environments PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Concrete Bridges In Aggressive Environments book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
Concrete Bridges In Aggressive Environments
DOWNLOAD
Author : Richard E. Weyers
language : en
Publisher:
Release Date : 1994
Concrete Bridges In Aggressive Environments written by Richard E. Weyers and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1994 with Technology & Engineering categories.
Concrete Bridges In Aggressive Environments
DOWNLOAD
Author :
language : en
Publisher:
Release Date : 1994
Concrete Bridges In Aggressive Environments written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1994 with Concrete bridges categories.
Sp 304 Sustainable Performance Of Concrete Bridges And Elements Subjected To Aggressive Environments
DOWNLOAD
Author : Yail J. Kim
language : en
Publisher:
Release Date : 2015
Sp 304 Sustainable Performance Of Concrete Bridges And Elements Subjected To Aggressive Environments written by Yail J. Kim and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015 with categories.
Sustainable Performance Of Concrete Bridges And Elements Subjected To Aggressive Environments Monitoring Evaluation Rehabilitation
DOWNLOAD
Author : Yail J. Kim
language : en
Publisher:
Release Date : 2016
Sustainable Performance Of Concrete Bridges And Elements Subjected To Aggressive Environments Monitoring Evaluation Rehabilitation written by Yail J. Kim and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016 with Concrete bridges categories.
Sustainability Assessment Of Concrete Bridge Deck Designs In Coastal Environments Using Neutrosophic Criteria Weights
DOWNLOAD
Author : Ignacio J. Navarro
language : en
Publisher: Infinite Study
Release Date :
Sustainability Assessment Of Concrete Bridge Deck Designs In Coastal Environments Using Neutrosophic Criteria Weights written by Ignacio J. Navarro and has been published by Infinite Study this book supported file pdf, txt, epub, kindle and other format this book has been release on with Mathematics categories.
Essential infrastructures such as bridges are designed to provide a long-lasting and intergenerational functionality. In those cases, sustainability becomes of paramount importance when the infrastructure is exposed to aggressive environments, which can jeopardise their durability and lead to significant maintenance demands. The assessment of sustainability is however often complex and uncertain. The present study assesses the sustainability performance of 16 alternative designs of a concrete bridge deck in a coastal environment on the basis of a neutrosophic group analytic hierarchy process (AHP). The use of neutrosophic logic in the field of multi-criteria decision-making, as a generalisation of the widely used fuzzy logic, allows for a proper capture of the vagueness and uncertainties of the judgements emitted by the decision-makers. TOPSIS technique is then used to aggregate the different sustainability criteria. From the results, it is derived that only the simultaneous consideration of the economic, environmental and social life cycle impacts of a design shall lead to adequate sustainable designs. Choices made based on the optimality of a design in only some of the sustainability pillars will lead to erroneous conclusions. The use of concrete with silica fume has resulted in a sustainability performance of 46.3% better than conventional concrete designs.
Service Life Prediction Method For Concrete And Prestressed Concrete Bridges Under Chloride Aggressive Environments
DOWNLOAD
Author : Ying Huang
language : en
Publisher:
Release Date : 2019
Service Life Prediction Method For Concrete And Prestressed Concrete Bridges Under Chloride Aggressive Environments written by Ying Huang and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019 with Concrete bridges categories.
The behavior of concrete and prestressed concrete bridges under chloride-aggressive environments during their service life is influenced not only by load (especially fatigue forces) but also by the corrosion environment. At present, the research of working performance and life prediction of bridges mainly focuses on the role of force or takes a single parameter as failure criterion, such as chloride ion concentration and steel bar depassivation. In this article, the service life prediction model of concrete and prestressed concrete bridges subjected to chloride-aggressive environments and fatigue is established, and the interaction of environmental effects and fatigue is taken into full account based on the mechanism of heat and mass transfer in porous media, the metal corrosion theory, and the classical mechanics theory. Taking depassivation as a demarcation point, the calculation method for the service life of concrete and prestressed concrete bridges is developed by analyzing the service life evolution process and determining the failure criterion. The service life of concrete bridges in coastal areas is calculated by the self-compiled program with MATLAB software (MathWorks, Natick, MA), and the results show good agreement with those in the project example. According to the results of the service life calculation with different increments of the number of fatigue loading cycles, ?N, the increment of the number of fatigue loading cycles ?Nhas an influence of no more than 5 % on the service life. This indicates that the calculation is converged and stable and that the calculation results are reliable. The service life of bridges is shortened with the increase of surface chloride concentration of concrete, daily vehicle traffic volume and load level, and the decrease of the concrete cover thickness. The study results are referred to predict the service life of concrete and prestressed concrete bridges under chloride-aggressive environments.
Structural Behavior Of Concrete Girders Prestressed With Stainless Steel Strands
DOWNLOAD
Author : Anwer Al-Kaimakchi
language : en
Publisher:
Release Date : 2020
Structural Behavior Of Concrete Girders Prestressed With Stainless Steel Strands written by Anwer Al-Kaimakchi and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020 with Civil engineering categories.
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.
Design Of Concrete Bridge Beams Prestressed With Cfrp Systems
DOWNLOAD
Author : Abdeldjelil Belarbi
language : en
Publisher:
Release Date : 2019
Design Of Concrete Bridge Beams Prestressed With Cfrp Systems written by Abdeldjelil Belarbi and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019 with Building materials categories.
This report proposes guidelines and presents research findings that are expected to advance and facilitate the use of CFRP systems in bridge applications. In addition, five design examples that illustrate the step-by-step use of the proposed guide specifications are provided. Carbon fiber reinforced polymer (CFRP) is becoming a recognized alternative to traditional construction materials in a wide range of civil engineering applications. An example of such applications is the use of CFRP cables or bars as prestressing tendons for concrete bridge girders, especially in aggressive environments where steel prestressing strands are susceptible to corrosion. Despite their promise, CFRP prestressing tendons have not frequently been used for bridge construction in the United States; their use has been hampered by the lack of recognized design specifications.
Fiber Reinforced Polymer Bridge Girders For Extremely Aggressive Environments
DOWNLOAD
Author : Abdellah Emad Azeez
language : en
Publisher:
Release Date : 2019
Fiber Reinforced Polymer Bridge Girders For Extremely Aggressive Environments written by Abdellah Emad Azeez and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2019 with Fiber-reinforced concrete categories.
In 2012, the federal government estimated that $17.5 billion was spent on inspection, rehabilitation, maintenance, and replacement of the nation's bridges. While the average lifespan of steel and reinforced concrete bridges is 50 years, certain bridges subjected to extremely aggressive marine environments may not reach this desired target. This research paper investigates using fiber-reinforced polymer (FRP) materials as primary bridge girders in medium span bridges (30 ft. to 75 ft.). The goal of this research is to identify the most efficient and cost-effective alternative for these corrosion-resistant materials and potentially extend the lifespan of these bridges up to 75 years. Three distinct profiles were investigated in this research : U-shaped, concrete-filled FRP tubes, and Double Web I-Beams (DWB). Finite Element Modeling (FEM) was used to study the overall stiffness of FRP girder bridges with a case-in-place concrete deck. Girder distribution factors for moment were also computed using reliability analysis tools and FEM. These results were then compared to existing AASHTO methods. Once the most efficient cross-section was identified (S-shaped girder), a preliminary study investigating the vacuum infusion manufacturing process was conducted to verify that the required thickness of FRP can be achieved. Simple bending tests were completed on small-scale FRP beams to demonstrate the strength capacity and evaluate any difficulties using the vacuum infusion process (VIP). The results in this research study conclude that the U-shaped bridge is the most cost-effective alternative, yet fabrication remains challenging and complicated.
Effect Of Voids In Grouted Post Tensioned Concrete Bridge Construction
DOWNLOAD
Author : David Trejo
language : en
Publisher:
Release Date : 2009
Effect Of Voids In Grouted Post Tensioned Concrete Bridge Construction written by David Trejo and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2009 with Concrete categories.