Concrete Structures Stresses And Deformations

This text presents the most effective analysis for predicting the true stresses and deflections of concrete structures, accounting for creep and shrinkage of concrete and relaxation of prestressed reinforcement. Sustainability has become a major requirement in modern structures, which need to sustain satisfactory service over a longer life. It is not rare to specify a life span of 100 years for infrastructure such as bridges. This complete and wide-ranging study of stresses and deformations of reinforced and prestressed concrete structures focuses on design methods for avoiding the deflections and cracking that diminish serviceability. This fourth edition has a new emphasis on designing for serviceability. It has been comprehensively updated. It now includes 65 solved examples and more than 45 instructive problems with answers given at the end of the book. An accompanying website contains design calculation programs, which allow interactive data input. Independent of codes of practice, the book is universally applicable, and is especially suitable for practising engineers and graduate students.

Concrete structures must be designed not only to be safe against failure but also to perform satisfactorily in use. This book is written for practising engineers and students, and focuses on design methods for checking deflections and cracking which can affect the serviceability of reinforced and prestressed concrete structures. The authors present accurate and easy-to-apply methods of analysing immediate and long-term stresses and deformations. These methods allow designers to account for variations of concrete properties from project to project and from country to country, making the book universally applicable. Comprehensively updated, this third edition of Concrete Structures also includes four new chapters covering such topics as: non-linear analysis of plane frames, design for serviceability of prestressed concrete, serviceability of members reinforced with fibre polymer bars, and the analysis of time-dependent internal forces with linear computer programs that are routinely used by structural designers. A website accompanies the book, featuring three design calculation programs related to stresses in cracked sections, creep coefficients and time-dependent analysis. The book contains numerous examples, some of which are worked out in the SI units and others in the Imperial units. The input data and the main results are given in both SI and Imperial units. The book is not tied to any specific code, although the latest American and European codes of practice are covered in the appendices.

Concrete structures must be designed both to be safe against failure and to perform satisfactorily in use. This book is written for practising engineers, students and designers and concentrates on design methods for checking the main serviceability requirements of control of deflections and cracking in reinforced and prestressed concrete structures.

This text presents the most effective analysis for predicting the true stresses and deflections of concrete structures, accounting for creep and shrinkage of concrete and relaxation of prestressed reinforcement. Sustainability has become a major requirement in modern structures, which need to sustain satisfactory service over a longer life. It is not rare to specify a life span of 100 years for infrastructure such as bridges. This complete and wide-ranging study of stresses and deformations of reinforced and prestressed concrete structures focuses on design methods for avoiding the deflections and cracking that diminish serviceability. This fourth edition has a new emphasis on designing for serviceability. It has been comprehensively updated. It now includes 65 solved examples and more than 45 instructive problems with answers given at the end of the book. An accompanying website contains design calculation programs, which allow interactive data input. Independent of codes of practice, the book is universally applicable, and is especially suitable for practising engineers and graduate students.

Serviceability failures of concrete structures involving excessive cracking or deflection are relatively common, even in structures that comply with code requirements. This is often as a result of a failure to adequately account for the time-dependent deformations of concrete in the design of the structure. The serviceability provisions embodied in codes of practice are relatively crude and, in some situations, unreliable and do not adequately model the in-service behaviour of structures. In particular, they fail to adequately account for the effects of creep and shrinkage of the concrete. Design for serviceability is complicated by the non-linear and inelastic behaviour of concrete at service loads. Providing detailed information, this book helps engineers to rationally predict the time-varying deformation of concrete structures under typical in-service conditions. It gives analytical methods to help anticipate time-dependent cracking, the gradual change in tension stiffening with time, creep induced deformations and the load independent strains caused by shrinkage and temperature changes. The calculation procedures are illustrated with many worked examples. A vital guide for practising engineers and advanced students of structural engineering on the design of concrete structures for serviceability and provides a penetrating insight into the time-dependent behaviour of reinforced and prestressed concrete structures.

The inability of designers of concrete structures to recognize and quantify the non-linear effects of cracking, creep and shrinkage is a common cause of serviceability failure. Such failures include excessive deflection, camber and/or shortening of members and excessive cracking which may cause aesthetic or durability problems. This book provides practising engineers with practical and usable techniques for predicting the non-linear effects of creep and shrinkage on the in-service behaviour of concrete structures. Both cracked and uncracked reinforced, prestressed, and composite members subjected to sustained loads or sustained deformations are considered. Analytical procedures are developed for the calculation of instantaneous and time-dependent stresses and deformations on cross-sections in both simple and continuous members. Numerous self-contained worked examples which clearly illustrate the analytical procedures are included. A wide variety of practical situations is considered. Listings of microcomputer programs for a number of the analyses are also presented.

17 2 STRESS FIELDS FOR SIMPLE STRUCTURES 2. 1 INTRODUCTION In this chapter the behavior and strength of simple structures made of rein forced or prestressed concrete is investigated with the aid of stress fields. In particular, the webs and flanges of beams, simple walls, brackets, bracing beams and joints of frames are investigated. By this means, the majority of design cases are already covered. In reality, all structural components are three-dimensional. Here, however, components are considered either directly as two-dimensional plate elements (i. e. the plane stress condition with no variation of stress over the thickness of the element) or they are subdivided into several plates. Since two-dimensional structural elements are statically redundant, it is pOSSible for a particular loading to be in equilibrium with many (theoretically an infinite number of) stress states. If the lower bound method of the theory of plasticity is employed, then an admissible stress field or any combination of such stress fields may be selected. In chapter 4 it is shown that this method is suitable for the design of reinforced concrete structures, and the consequence of the choice of the final structural system on the structural behavior is dealt with in detail. The first cases of the use of this method date back to Ritter [6] and Morsch [4], who already at the beginning of the century investigated the resultants of the internal stresses by means of truss models.