The subjects of the symposia are on composite materials with matrices behaving as brittle in normal or special conditions. Brittle matrix composites are applied in various domains (civil engineering, mechanical equipment and machinery, vehicles, etc.) and in the last decades their importance is increasing together with their variety. Papers include: aggregate-binder composites (concretes, fibre concretes, rocks); sintered materials (ceramics); high strength composites with brittle matrices. In principle, the general problems of structures made of composite materials are not included in the papers. Various approaches to the material engineering problems are presented in the papers.
The International Symposium in Brittle Matrix Composites October 13-15, 2003 covers a wide spectrum of topics including cement based composites, ceramic composites and brittle polymer matrix composites. In the papers various topics and issues are considered such as: analytical and numerical studies related to the design of composites, prediction of behaviour and verification of strength and stability, testing methods, manufacturing processes and repair, environmental effects and durability assessment. The present volume of 55 papers proves that there are still many problems in the field of brittle matrix composites deserving theoretical and experimental investigations and that new solutions to these problems are needed for practical application in civil engineering, industrial structures, machinery and other domains.
The subjects of the symposia are on composite materials behaving as brittle, normal and special conditions of exploitation. Brittle matrix composites are applied in various domains and the series of symposia are closely related to their applications in civil engineering. In the last decades their importance is increasing along with their variety and the use of most advanced methods of testing. Papers include concretes, fibre concretes and ceramics, particularly their composition, microstructure and fracture processes. Various new and advanced engineering problems are presented in the papers.
Construction industry like any other area of economic and social life undergoes continuous alterations and improvements in order to successfully comply with the requirements of sustainable development. Consumers demand more durable, less labour and service intensive materials at a competitive price. To meet these expectations numerous new composite materials have been developed over the last couple of decades, including cementitious materials modified by superabsorbent polymers (SAP). The paper presents part of the larger research project on the performance of cementitious mortars containing two types of superabsorbent polymers (SAP) as the internal curing agent.SAP A is a copolymer of acrylamide and acrylic acid and SAP B is a polymer based on acrylic acid. Research work presented in this paper involves macro and micro scale characterisation of polymer modified mortars. The microstructural features were studied with application of the Mercury Intrusion Porosimetry and the Scanning Electron Microscopy techniques. Analyses of pore size distribution in mortars of different ages are accompanied by the analyses of strength and autogenous shrinkage development as well as early density changes in immature mortars by the X-ray absorption method. The investigations confirmed the positive effect of SAP A on the reduction of autogenous shrinkage and microcrack propagation. Limited absorption/desorption abilities of SAP B cannot reassure continuous supply of water and hence the performance of SAP B mortars was comparable with the reference samples. The effect of both SAPs on strength development proved to be negligible.
This paper presents the results from an experimental study on the behaviour of Reactive Powder Concretes (RPC) at high temperature. The exposure to high temperature is related to the potential risk of fire. A previous study has shown that RPC is prone to spalling in such circumstances and for this reason polypropylene fibres were used in RPC concrete to prevent this occurring. The addition of PP fibres reduces the risk of spalling due to an increase in permeability, however it reduces the initial compressive strength of the RPC material by approx. 20 %. The results demonstrate that the strength of concrete along with the modulus of elasticity decrease with increasing temperature. Two experimental concretes were prepared and prismatic specimens, 40x40x80mm in size, were cast from each mixture and tested in compression after being submitted to the high temperature. The relative value of compressive strength course for both types of concrete shows a similar development. The change in modulus of elasticity with temperature was determined from the stress-strain relationship and compared with the dynamic modulus of elasticity determined with the use of a Pundit plus ultrasonic pulse velocity defectoscope.
The aim of the paper was to show the important aspect of treating waste additives as the main way to achieve sustainable development in the concrete technology. The author considers the effects of minimizing the use of cement replacing it with waste additives, on the concrete durability. The depth of carbonation is adopted as the possible measure of durability. Results of accelerated and natural tests of carbonation progress for concrete with normal and fluidal fly ash, silica fume and blast furnace slag are shown, influence on carbonation of the additive type, its content in concrete and its role (cement or aggregate substitution) is discussed. The important impact of early water curing on depth of carbonation is stated also.
|Author||: Jacques Lamon|
|Release Date||: 2016-03-16|
|ISBN 10||: 008101161X|
|Pages||: 296 pages|
Flaws are the principal source of fracture in many materials, whether brittle or ductile, whether nearly homogeneous or composite. They are introduced during either fabrication or surface preparation or during exposure to aggressive environments (e. g. oxidation, shocks). The critical flaws act as stress concentrators and initiate cracks that propagate instantaneously to failure in the absence of crack arrest phenomena as encountered in brittle materials. This book explores those brittle materials susceptible to crack arrest and the flaws which initiate crack induced damage. A detailed description of microstructural features covering numerous brittle materials, including ceramics, glass, concrete, metals, polymers and ceramic fibers to help you develop your knowledge of material fracture. Brittle Failure and Damage of Brittle Materials and Composites outlines the technological progress in this field and the need for reliable systems with high performances to help you advance the development of new structural materials, creating advantages of low density, high resistance to elevated temperatures and aggressive environments, and good mechanical properties. The effects of flaw populations on fracture strength The main statistical-probabilistic approaches to brittle fracture The use of these methods for predictions of failure and effects induced by flaw populations The application of these methods to component design The methods of estimation of statistical parameters that define flaw strength distributions The extension of these approaches to damage and failure of continuous fiber reinforced ceramic matrix composites
Ceramic matrix composites (CMCs) have proven to be useful for a wide range of applications because of properties such as their light weight, toughness and temperature resistance. Advances in ceramic matrix composites summarises key advances and types of processing of CMCs. After an introductory chapter, the first part of the book reviews types and processing of CMCs, covering processing, properties and applications. Chapters discuss nanoceramic matric composites, silicon carbide-containing alumina nanocomposites and advances in manufacture by various infiltration techniques including heat treatments and spark plasma sintering. The second part of the book is dedicated to understanding the properties of CMCs with chapters on Finite Element Analysis, tribology and wear and self-healing CMCs. The final part of the book examines the applications of CMCs, including those in the structural engineering, nuclear and fusion energy, turbine, metal cutting and microelectronics industries. Advances in ceramic matrix composites is an essential text for researchers and engineers in the field of CMCs and industries such as aerospace and automotive engineering. Reviews types and processing of CMCs, covering processing, properties and applications
This book is a comprehensive source of information on various aspects of ceramic matrix composites (CMC). It covers ceramic and carbon fibers; the fiber-matrix interface; processing, properties and industrial applications of various CMC systems; architecture, mechanical behavior at room and elevated temperatures, environmental effects and protective coatings, foreign object damage, modeling, life prediction, integration and joining. Each chapter in the book is written by specialists and internationally renowned researchers in the field. This book will provide state-of-the-art information on different aspects of CMCs. The book will be directed to researchers working in industry, academia, and national laboratories with interest and professional competence on CMCs. The book will also be useful to senior year and graduate students pursuing degrees in ceramic science and engineering, materials science and engineering, aeronautical, mechanical, and civil or aerospace engineering. Presents recent advances, new approaches and discusses new issues in the field, such as foreign object damage, life predictions, multiscale modeling based on probabilistic approaches, etc. Caters to the increasing interest in the application of ceramic matrix composites (CMC) materials in areas as diverse as aerospace, transport, energy, nuclear, and environment. CMCs are considered ans enabling technology for advanced aeropropulsion, space propulsion, space power, aerospace vehicles, space structures, as well as nuclear and chemical industries. Offers detailed descriptions of ceramic and carbon fibers; fiber-matrix interface; processing, properties and industrial applications of various CMC systems; architecture, mechanical behavior at room and elevated temperatures, environmental effects and protective coatings, foreign object damage, modeling, life prediction, integration/joining.
|Author||: M'hamed Ibnabdeljalil|
|Release Date||: 1994|
|Pages||: 378 pages|
Composite Materials, Volume 5: Fracture and Fatigue covers the concepts, theories, and experiments on fracture and fatigue behavior of composite materials. The book discusses the fracture of particulate composites, including metal, polymer, and ceramic matrices; relates micromechanics effects to composite strength; and summarizes the various theories relating constituent properties and microstructure to fracture. The text also describes differing theories regarding the strength and fracture of composites; and the theory and experiment relating to time-dependent fracture covering both long-term as well as dynamic fracture. The fatigue of both polymer- and metal-matrix composites and the factors influencing the toughness of both brittle and ductile matrix composites are also considered. Design engineers, materials scientist, materials engineers, and metallurgists will find the book useful.