Download or read book Impact of Small Organic Molecules on the Nucleation of Calcium Silicate Hydrate written by Lina Bouzouaid and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superplasticizers are nowadays commonly employed in concrete to improve its workability and mechanical performance. They generally have the side effect of retarding the hydration of Portland cement which results from two simultaneous reactions: the dissolution of cement grains and the precipitation of cement hydrates. The mechanisms responsible for this retardation and thus delay the setting time of cement remain however largely unexplained. The present work intended to tackle this puzzle from the perspective of cement hydrate formation and employing four small organic molecules as model for superplasticizers. In particular, the impact of these organics on the homogeneous nucleation of calcium silicate hydrate (C-S-H) was studied in detailed. The work further focused on the determination of the driving force of the nucleation (and dissolution) and thus on the determination and modeling of the ion speciation and organic complex formation with calcium, silicate and hydroxide aqueous species. The selected organics whether charged or neutral were all found to form a rich zoo of mono- and poly-nuclear complexes not only with calcium and hydroxide ions but also with silicate species. They were further successfully modeled with the speciation program PHREEQC. This allowed to compare and quantify the impact of the selected organic molecules on the nucleation rate of C-S-H. The nucleation rate was correlated to the complexation power of the organics. A modification of the C-S-H nucleation pathway induced by the organics was found for which the organic complexation with silicate and calcium ions seems to play a crucial role. More generally, the retardation power of the molecules on the hydration of alite, the main mineral phase of Portland cement, was found to correlate well with their impact on the nucleation rate of C-S-H.
Download or read book Effect of Ions and Admixtures on the Growth of Synthetic Calcium Silicate Hydrate C S H written by Jirawan Siramanont and published by . This book was released on 2018 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mots-clés de l'auteur: Calcium silicate hydrate ; Fe (III) ; D-gluconate ; heterogeneous substrate ; quartz ; calcite ; synthetic C-S-H ; nucleation and growth ; aggregation ; dropwise precipitation.
Download or read book Cement Based Materials written by Hosam El-Din M. Saleh and published by BoD – Books on Demand. This book was released on 2018-10-10 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cement-based materials have been used by humans nearly since the dawn of civilization. The Egyptians used lime and gypsum cement to bind their aggregate materials, mud and straw, resulting in bricks that are used for building their famous Egyptian pyramids (between 3000 and 2500 BC). Hydrated cement is a cement material bonded together with water and used for building construction; it is characterized by acceptable chemical, physical, thermal, mechanical, and structural stability. It plays a main role in the creation of vessels for storage, roads to travel on, weather-resistant structure for protection, inert hard stabilizer for hazardous wastes, and so on. Due to the composition of these materials and their advantages, it has been practiced in different applications. Cement is an essential component of making concrete, the single most prevalent building material used worldwide for construction, skyscrapers, highways, tunnels, bridges, hydraulic dams, and railway ties. Besides their numerous desired properties, there are some undesirable features. To overcome these disadvantages, several studies were established to prepare, improve, and evaluate innovative cement-based materials. Despite its oldness and deep research, every year several methods and materials evolve and so do cement technology. This book intends to provide a comprehensive overview on recent advances in the evaluation of these materials.
Download or read book Science and Technology of Concrete Admixtures written by Pierre-Claude Aïtcin and published by Woodhead Publishing. This book was released on 2015-11-12 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt: Science and Technology of Concrete Admixtures presents admixtures from both a theoretical and practical point-of-view. The authors emphasize key concepts that can be used to better understand the working mechanisms of these products by presenting a concise overview on the fundamental behavior of Portland cement and hydraulic binders as well as their chemical admixtures, also discussing recent effects in concrete in terms of rheology, mechanics, durability, and sustainability, but never forgetting the fundamental role played by the water/binder ratio and proper curing in concrete technology. Part One presents basic knowledge on Portland cement and concrete, while Part Two deals with the chemical and physical background needed to better understand what admixtures are chemically, and through which mechanism they modify the properties of the fresh and hardened concrete. Subsequent sections present discussions on admixtures technology and two particular types of concrete, self-consolidating and ultra-high strength concretes, with final remarks on their future. Combines the knowledge of two leading authors to present both the scientific and technology of admixtures Explains what admixtures are from a chemical point-of-view and illustrates by which mechanisms they modify the properties of fresh and hardened concrete Presents a fundamental, practical, and innovative reference book on the topic Contains three detailed appendices that can be used to learn how to use admixtures more efficiently
Download or read book Calcium Orthophosphates written by Sergey V. Dorozhkin and published by CRC Press. This book was released on 2012-06-04 with total page 863 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to a great chemical similarity with the biological calcified tissues, many calcium orthophosphates possess remarkable biocompatibility and bioactivity. Materials scientists use this property extensively to construct artificial bone grafts that are either entirely made of or only surface-coated with the biologically relevant calcium orthophospha
Download or read book Molecular Simulation on Cement Based Materials written by Dongshuai Hou and published by Springer Nature. This book was released on 2019-09-26 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a number of studies on the molecular dynamics of cement-based materials. It introduces a practical molecular model of cement-hydrate, delineates the relationship between molecular structure and nanoscale properties, reveals the transport mechanism of cement-hydrate, and provides useful methods for material design. Based on the molecular model presented here, the book subsequently sheds light on nanotechnology applications in the design of construction and building materials. As such, it offers a valuable asset for researchers, scientists, and engineers in the field of construction and building materials.
Download or read book Nucleation Theory written by V.I. Kalikmanov and published by Springer. This book was released on 2012-11-28 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the most striking phenomena in condensed matter physics is the occurrence of abrupt transitions in the structure of a substance at certain temperatures or pressures. These are first order phase transitions, and examples such as the freezing of water are familiar in everyday life. The conditions at which the transformation takes place can sometimes vary. For example, the freezing point of water is not always 0°C, but the liquid can be supercooled considerably if it is pure enough and treated carefully. The reason for this phenomenon is nucleation. This monograph covers all major available routes of theoretical research of nucleation phenomena (phenomenological models, semi-phenomenological theories, density functional theories, microscopic and semi-microscopic approaches), with emphasis on the formation of liquid droplets from a metastable vapor. Also, it illustrates the application of these various approaches to experimentally relevant problems. In spite of the familiarity of the involved phenomena, it is still impossible to calculate nucleation accurately, as the properties and the kinetics of the daughter phase are insufficiently well known. Existing theories based upon classical nucleation theory have on the whole explained the trends in behavior correctly. However they often fail spectacularly to account for new data, in particular in the case of binary or, more generally, multi-component nucleation. The current challenge of this book is to go beyond such classical models and provide a more satisfactory theory by using density functional theory and microscopic computer simulations in order to describe the properties of small clusters. Also, semi-phenomenological models are proposed, which attempt to relate the properties of small clusters to known properties of the bulk phases. This monograph is an introduction as well as a compendium to researchers in soft condensed matter physics and chemical physics, graduate and post-graduate students in physics and chemistry starting on research in the area of nucleation, and to experimentalists wishing to gain a better understanding of the efforts being made to account for their data.
Download or read book Cement and Concrete Chemistry written by Wieslaw Kurdowski and published by Springer Science & Business. This book was released on 2014-04-24 with total page 705 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph describes cement clinker formation. It covers multicomponent systems, clinker phase structures and their reactions with water, hydrate composition and structure, as well as their physical properties. The mineral additions to cement are described as are their influence on cement-paste properties. Special cements are also discussed. The microstructure of concrete is then presented, and special emphasis is given to the role of the interfacial transition zone, and the corrosion processes in the light of cement-phase composition, mineral additions and w/c ratio. The admixtures' role in modern concrete technology is described with an emphasis on superplasticizer chemistry and its cement-paste rheological modification mechanism. Cement with atypical properties, such as calcium aluminate, white, low energy and expansive cements are characterized. The last part of the book is devoted to special types of concrete such as self compacting and to reactive powders.
Download or read book Cement Chemistry written by H F W Taylor and published by Thomas Telford. This book was released on 1997-04 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: A revised and updated text on cement chemistry. This edition forms a comprehensive and in-depth reference work that explains in detail all aspects of cement chemistry.
Download or read book New Perspectives on Mineral Nucleation and Growth written by Alexander E.S. Van Driessche and published by Springer. This book was released on 2017-01-04 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last decade, numerous studies have demonstrated the existence of alternative pathways to nucleation and crystallisation that oppose the classical view. Such proposed scenarios include multistage reactions proceeding via various precursor species and/or intermediate phases. The aim of this book is to review and discuss these recent advances in our understanding of the early stages of mineralisation through a series of contributions that address both experimental and theoretical studies about the formation and nature of initial precursor species (e.g., prenucleation clusters, dense liquid phases, amorphous nanoparticles, etc.) as well as their transformations leading to the stable mineral phase. Several chapters are devoted to cutting-edge analytical techniques used for investigating the above processes in situ, in real time and at conditions relevant to both natural and industrial processes. At the end of the book, the editors summarize the key questions that still need to be addressed in order to establish a complete picture of the nucleation and growth processes involved during the formation of minerals
Download or read book Bioavailability of Contaminants in Soils and Sediments written by National Research Council and published by National Academies Press. This book was released on 2003-05-03 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bioavailability refers to the extent to which humans and ecological receptors are exposed to contaminants in soil or sediment. The concept of bioavailability has recently piqued the interest of the hazardous waste industry as an important consideration in deciding how much waste to clean up. The rationale is that if contaminants in soil and sediment are not bioavailable, then more contaminant mass can be left in place without creating additional risk. A new NRC report notes that the potential for the consideration of bioavailability to influence decision-making is greatest where certain chemical, environmental, and regulatory factors align. The current use of bioavailability in risk assessment and hazardous waste cleanup regulations is demystified, and acceptable tools and models for bioavailability assessment are discussed and ranked according to seven criteria. Finally, the intimate link between bioavailability and bioremediation is explored. The report concludes with suggestions for moving bioavailability forward in the regulatory arena for both soil and sediment cleanup.
Download or read book Lea s Chemistry of Cement and Concrete written by Peter Hewlett and published by Elsevier. This book was released on 2003-11-12 with total page 1087 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lea's Chemistry of Cement and Concrete deals with the chemical and physical properties of cements and concretes and their relation to the practical problems that arise in manufacture and use. As such it is addressed not only to the chemist and those concerned with the science and technology of silicate materials, but also to those interested in the use of concrete in building and civil engineering construction. Much attention is given to the suitability of materials, to the conditions under which concrete can excel and those where it may deteriorate and to the precautionary or remedial measures that can be adopted. First published in 1935, this is the fourth edition and the first to appear since the death of Sir Frederick Lea, the original author. Over the life of the first three editions, this book has become the authority on its subject. The fourth edition is edited by Professor Peter C. Hewlett, Director of the British Board of Agrement and visiting Industrial Professor in the Department of Civil Engineering at the University of Dundee. Professor Hewlett has brought together a distinguished body of international contributors to produce an edition which is a worthy successor to the previous editions.
Download or read book Mineral Scale Formation and Inhibition written by Z. Amjad and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book documents the proceedings of the symposium, "Mineral Scale Formation and Inhibition," held at the American Chemical Society Annual Meeting August 21 to 26, 1994, in Washington, D. C. The symposium, sponsored by the Division of Colloid and Surface Chemistry, was held in honor of Professor George H. Nancollas for his pioneering work in the field of crystal growth from solution. A total of 30 papers were presented by a wide spectrum of scientists. This book also includes papers that were not presented but were in the symposium program. The separation of a solid by crystallization is one of the oldest and perhaps the most frequently used operations in chemistry. Because of its widespread applicability, in recent years there has been considerable interest exhibited by academic and industrial scientists in understanding the mechanisms of crystallization of sparingly soluble salts. The salt systems of great interest in industrial water treatment area (i. e. , cooling and boiler) include carbon ates, sulfates, phosphates, and phosphonates of alkaline earth metals. Although not as common as calcium carbonate and calcium sulfate, barium and strontium sulfates have long plagued oil field and gas production operations. The build-up of these sparingly soluble salts on equipment surfaces results in lower heat transfer efficiency, increased corrosion rates, increased pumping costs, etc. In the laundry application, insoluble calcium carbonate tends to accumulate on washed fabrics and washing equipment parts, resulting in undesirable fabric-encrustation or scaling.
Download or read book Introduction to Glass Science and Technology written by James E Shelby and published by Royal Society of Chemistry. This book was released on 2015-11-06 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a concise and inexpensive introduction for an undergraduate course in glass science and technology. The level of the book has deliberately been maintained at the introductory level to avoid confusion of the student by inclusion of more advanced material, and is unique in that its text is limited to the amount suitable for a one term course for students in materials science, ceramics or inorganic chemistry. The contents cover the fundamental topics of importance in glass science and technology, including glass formation, crystallization, phase separation and structure of glasses. Additional chapters discuss the most important properties of glasses, including discussion of physical, optical, electrical, chemical and mechanical properties. A final chapter provides an introduction to a number of methods used to form technical glasses, including glass sheet, bottles, insulation fibre, optical fibres and other common commercial products. In addition, the book contains discussion of the effects of phase separation and crystallization on the properties of glasses, which is neglected in other texts. Although intended primarily as a textbook, Introduction to Glass Science and Technology will also be invaluable to the engineer or scientist who desires more knowledge regarding the formation, properties and production of glass.
Download or read book Handbook of Industrial Crystallization written by Allan Myerson and published by Butterworth-Heinemann. This book was released on 2002-01-08 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crystallization is an important separation and purification process used in industries ranging from bulk commodity chemicals to specialty chemicals and pharmaceuticals. In recent years, a number of environmental applications have also come to rely on crystallization in waste treatment and recycling processes.The authors provide an introduction to the field of newcomers and a reference to those involved in the various aspects of industrial crystallization. It is a complete volume covering all aspects of industrial crystallization, including material related to both fundamentals and applications. This new edition presents detailed material on crystallization of biomolecules, precipitation, impurity-crystal interactions, solubility, and design. Provides an ideal introduction for industrial crystallization newcomers Serves as a worthwhile reference to anyone involved in the fieldCovers all aspects of industrial crystallization in a single, complete volume
Download or read book Phosphorus Polluter and Resource of the Future written by Christian Schaum and published by IWA Publishing. This book was released on 2018-03-15 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive book provides an up-to-date and international approach that addresses the Motivations, Technologies and Assessment of the Elimination and Recovery of Phosphorus from Wastewater. This book is part of the Integrated Environmental Technology Series.
Download or read book Atmospheric Aerosols written by Claudio Tomasi and published by John Wiley & Sons. This book was released on 2017-03-20 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ein Blick auf die morphologischen, physikalischen und chemischen Eigenschaften von Aerosolen aus den unterschiedlichsten natürlichen und anthropogenen Quellen trägt zum besseren Verständnis der Rolle bei, die Aerosolpartikel bei der Streuung und Absorption kurz- und langwelliger Strahlung spielen. Dieses Fachbuch bietet Informationen, die sonst schwer zu finden sind, und vermittelt ausführlich die Kenntnisse, die erforderlich sind, um die mikrophysikalischen, chemischen und Strahlungsparameter zu charakterisieren, die bei der Wechselwirkung von Sonnen- und Erdstrahlen so überaus wichtig sind. Besonderes Augenmerk liegt auf den indirekten Auswirkungen von Aerosolen auf das Klima im Rahmen des komplexen Systems aus Aerosolen, Wolken und der Atmosphäre. Auch geht es vorrangig um die Wirkungen natürlicher und anthropogener Aerosole auf die Luftqualität und die Umwelt, auf die menschliche Gesundheit und unser kulturelles Erbe. Mit einem durchgängig lösungsorientierten Ansatz werden nicht nur die Probleme und Gefahren dieser Aerosole behandelt, sondern auch praktikable Lösungswege aufgezeigt.
