Development of Load and Resistance Factor Design for FRP Strengthening of Reinforced Concrete Bridges


Book Description

Techniques for reliability analysis are discussed, and existing work on externally bonded FRP reliability is surveyed. Stochastic variation in the FRP is characterized based on tensile testing of several sets of field-manufactured, wet layup composites. A general design procedure applicable to many different situations is proposed using a composite specific resistance factor to consider material variability, a set of Application Factors to account for deviations introduced through field manufacture, and an environment and service-life specific factor for FRP degradation. Preliminary resistance factors for design of FRP strengthening are calibrated over a range of design scenarios. FRP degradation is considered based on existing durability models, and continued degradation of the structure due to general corrosion of the reinforcing steel is included. The girders used for calibration are selected as representative examples from a sample of California bridge plans.







Recommended Guide Specification for the Design of Externally Bonded FRP Systems for Repair and Strengthening of Concrete Bridge Elements


Book Description

TRB's National Cooperative Highway Research Program (NCHRP) Report 655: Recommended Guide Specification for the Design of Externally Bonded FRP Systems for Repair and Strengthening of Concrete Bridge Elements examines a recommended guide specification for the design of externally bonded Fiber-Reinforced Polymer (FRP) systems for the repair and strengthening of concrete bridge elements. The report addresses the design requirements for members subjected to different loading conditions including flexure, shear and torsion, and combined axial force and flexure. The recommended guide specification is supplemented by design examples to illustrate its use for different FRP strengthening applications.




Innovative Bridge Design Handbook


Book Description

As known, each bridge presents a unique set of design, construction, and maintenance challenges. The designer must determine the appropriate methods and level of refinement necessary to design and analyze each bridge on a case-by-case basis. The Innovative Bridge Design Handbook: Construction, Rehabilitation, and Maintenance encompasses the state of the art in bridge design, construction, maintenance, and safety assessment. Written by an international group of experts, this book provides innovative design approaches used in various parts of the world and explores concepts in design, construction, and maintenance that will reduce project costs and increase structural safety and durability. Furthermore, research and innovative solutions are described throughout chapters. The Innovative Bridge Design Handbook: Construction, Rehabilitation, and Maintenance brings together the specific knowledge of a bevy of experts and academics in bridge engineering in the areas of design, assessment, research, and construction. The handbook begins with an analysis of the history and development of bridge aesthetics and design; various types of loads including seismic and wind loads are then described, together with fatigue and fracture. Bridge design based on material such as reinforced concrete, prestressed reinforced concrete, steel and composite, timber, masonry bridges is analyzed and detailed according to international codes and standards. Then bridge design based on geometry, such as arch bridges, girders, cable stayed and suspension bridges, is illustrated. This is followed by a discussion of a number of special topics, including integral, movable, highway and railway bridges, together with seismic component devices, cables, orthotropic decks, foundations, and case studies. Finally, bridge construction equipment, bridge assessment retrofit and management, bridge monitoring, fiber-reinforced polymers to reinforce bridges, bridge collapse issues are covered. - Loads including seismic and wind loads, fatigue and fracture, local effects - Structural analysis including numerical methods (FEM), dynamics, risk and reliability, innovative structural typologies - Bridge design based on material type: RC and PRC, steel and composite, timber and masonry bridges - Bridge design based on geometry: arch bridges, girders, cable stayed and suspension bridges - Special topics: integral, movable, highway, railway bridges, seismic component devices, cables, orthotropic decks, foundations - Construction including construction case studies, construction equipment, bridge assessment, bridge management, retrofit and strengthening, monitoring procedures










Service Life Estimation and Extension of Civil Engineering Structures


Book Description

Service life estimation is an area of growing importance in civil engineering both for determining the remaining service life of civil engineering structures and for designing new structural systems with well-defined periods of functionality. Service life estimation and extension of civil engineering structures provides valuable information on the development and use of newer and more durable materials and methods of construction, as well as the development and use of new techniques of estimating service life.Part one discusses using fibre reinforced polymer (FRP) composites to extend the service-life of civil engineering structures. It considers the key issues in the use of FRP composites, examines the possibility of extending the service life of structurally deficient and deteriorating concrete structures and investigates the uncertainties of using FRP composites in the rehabilitation of civil engineering structures. Part two discusses estimating the service life of civil engineering structures including modelling service life and maintenance strategies and probabilistic methods for service life estimation. It goes on to investigate non-destructive evaluation and testing (NDE/NDT) as well as databases and knowledge-based systems for service life estimation of rehabilitated civil structures and pipelines.With its distinguished editors and international team of contributors Service life estimation and extension of civil engineering structures is an invaluable resource to academics, civil engineers, construction companies, infrastructure providers and all those with an interest in improving the service life, safety and reliability of civil engineering structures. - A single source of information on the service life of reinforced concrete and fibre-reinforced polymer (FRP) rehabilitated structures - Examines degradation mechanisms in composites for rehabilitation considering uncertainties in FRP reliability - Provides an overview of probabilistic methods for rehabilitation and service life estimation of corroded structures




Reliability Based Assessment of FRP Rehabilitation of Reinforced Concrete Girders


Book Description

The use of prefabricated fiber reinforced polymer (FRP) strips to rehabilitate concrete structures has increased in popularity over the past few years. As such, many design codes and guidelines have been developed to enable designers to use the FRP materials with confidence in their performance. In this work, FRP durability test results are used with a widely known degradation prediction model to determine the value of FRP material properties used in rehabilitation and strengthening of concrete over time. Equations are presented based on the test data to predict the tensile strength, tensile modulus, short beam shear strength, and flexural strength over time of FRP prefabricated strips from three manufacturers. Corresponding degradation data is presented for the adhesive recommended be each manufacturer for use. The degradation model is used on example girders used in previous research by Atadero and Karbhari (1996) for illustration of differences in the codes and guidelines design property values and those possessed by FRP materials over time to demonstrate the use of the time-based reliability factor within the LRFD model presented in an earlier report to Caltrans. A reliability analysis is conducted in each example case to compare the results. A proposed shift in design philosophy is presented to enable inclusion of material degradation over time and thereby make concrete rehabilitation with FRP strips more efficient and cost effective.







Steel Fiber Reinforced Concrete


Book Description

This book discusses design aspects of steel fiber-reinforced concrete (SFRC) members, including the behavior of the SFRC and its modeling. It also examines the effect of various parameters governing the response of SFRC members in detail. Unlike other publications available in the form of guidelines, which mainly describe design methods based on experimental results, it describes the basic concepts and principles of designing structural members using SFRC as a structural material, predominantly subjected to flexure and shear. Although applications to special structures, such as bridges, retaining walls, tanks and silos are not specifically covered, the fundamental design concepts remain the same and can easily be extended to these elements. It introduces the principles and related theories for predicting the role of steel fibers in reinforcing concrete members concisely and logically, and presents various material models to predict the response of SFRC members in detail. These are then gradually extended to develop an analytical flexural model for the analysis and design of SFRC members. The lack of such a discussion is a major hindrance to the adoption of SFRC as a structural material in routine design practice. This book helps users appraise the role of fiber as reinforcement in concrete members used alone and/or along with conventional rebars. Applications to singly and doubly reinforced beams and slabs are illustrated with examples, using both SFRC and conventional reinforced concrete as a structural material. The influence of the addition of steel fibers on various mechanical properties of the SFRC members is discussed in detail, which is invaluable in helping designers and engineers create optimum designs. Lastly, it describes the generally accepted methods for specifying the steel fibers at the site along with the SFRC mixing methods, storage and transport and explains in detail methods to validate the adopted design. This book is useful to practicing engineers, researchers, and students.