Chemical admixtures are used to modify the properties and behaviour of fresh and hardened concrete. They enable more economic construction and the achievement of special properties such as high strength or durability. This book presents new research information from an International RILEM Symposium on six main topics: workability, setting, strength, durability, other properties and technology.
Since the publication of the first edition ten years ago, significant developments have occurred in the use of admixtures in concrete. Eight new chapters and a full update of the preceding ten chapters bring this book up to date; reflecting the relative advances made in the science and technology of different groups of admixtures. The increased role and development of admixtures in concrete technology is evidenced by a number of conferences, publications, and novel admixtures available in the market place. These developments in the field caused the modification of many chapters in the first edition in order to reflect the advances. Although individual chapters refer to standards and specifications of admixtures, those only interested in the standards or techniques used in investigating admixtures will find the second chapter (Research Technologies, Standards, and Specifications) useful. Admixtures are not as inert as may be presumed. They may chemically interact with the constituents of concrete and affect the properties of the fresh and hardened concrete and its durability. The third chapter deals with these aspects. It was important to devote a chapter to recent attempts in developing new admixtures.
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
Chemical admixtures are used in concrete mixtures to produce particular engineering properties such as rapid hardening, water-proofing or resistance to cold. Chemical Admixtures for Concrete surveys recent developments in admixture technology, explaining the mechanisms by which admixtures produce their effects, the various types of admixtures avail
Over the past two decades concrete has enjoyed a renewed level of research and testing, resulting in the development of many new types of concrete. Through the use of various additives, production techniques and chemical processes, there is now a great degree of control over the properties of specific concretes for a wide range of applications. New theories, models and testing techniques have also been developed to push the envelope of concrete as a building material. There is no current textbook which brings all of these advancements together in a single volume. This book aims to bridge the gap between the traditional concrete technologies and the emerging state-of-the-art technologies which are gaining wider use.
This book discusses the detailed concepts of concrete and its development with pros and cons. Besides, the significance of various industrial wastes as partial replacements with concrete ingredients such as cement and aggregates are discussed. The creation of cement contributes to around 7% of carbon emissions into the atmosphere leading to greenhouse effect and global warming. Similarly, the wastes generated from various industries such as thermal, steel, ceramic, marble, paper and etc. shows the impact on atmosphere and leads to air pollution and land pollution. Thus, it is essential to focus on these wastes to use them in a profitable manner without compromising the current needs. This book discusses a few examples on studies of using various industry wastes as partial replacement of cement in concrete
Written to meet the requirements of engineers working in construction and concrete manufacturing, Mineral Admixtures in Cement and Concrete focuses on how to make more workable and durable concrete using mineral admixtures. In particular, it covers pulverized fuel ash (PFA), blast furnace slag (BFS), silica fume (SF), rice husk ash (RHA), and metak
An admixture is any material other than water, aggregates, and hydraulic cement that is used as an ingredient of a concrete or mortar mixture and added to the batch immediately before or during mixing. 4 types of admixtures are discussed: (1) accelerators, the most common of which is calcium chloride; (2) air-entraining, to protect the concrete against the damage it may suffer if the paste becomes saturated with water and then freezes; (3) retarders and water reducers, which extend setting time 30 to 50 percent to compensate for placement temperatures, to avoid cold joints, or to avoid undesirable effects of displacements and deflections; and (4) pozzolans, which react with hydroxides to form compounds with cementitious properties, and usually produce a lower cost concrete.
Supplementary cementing materials and other mineral admixtures are being used in increasing amounts in both cement and concrete. Their main technical benefits are that they enhance the workability of fresh concrete and the durability of hardened concrete. Indeed, they affect almost every property of the concrete. Their economic and ecological benef
Mortar and concrete made with portland cement has been a popular construction material in the world for the past 170 years or more. However, cement mortar and concrete have some disadvantages such as delayed hardening, low tensile strength, large drying shrinkage and low chemical resistance. To reduce these disadvantages, polymers have been utilized as an additive.Polymer-modified or polymer cement mortar (PCM) and concrete (PCC) are the materials which are made by partially replacing the cement hydrate binders of conventional cement mortar or concrete, with polymers. This book deals with the principles of polymer modification for cement composites, the process technology, properties and applications of the polymer-modified mortar and concrete, and special polymer-modified systems such as M DF cement, antiwashout underwater concrete, polymer-ferrocement, and artificial I wood.The polymeric admixtures or cement modifiers include latexes or emulsions, redispersible polymer powders, water-soluble polymers, liquid resins and monomers.This book describes the current knowledge and information of polymer-modified mortars and concretes, and discusses or reviews the following items in detail:1. Principles of polymer modification for cement composites.2. Process technology of polymer-modified mortars and concretes.3. Properties of polymer-modified mortars and concretes.4. Applications of polymer-modified mortars and concretes.5. Special polymer-modified systems such as MDF cements, antiwashout underwater concretes, polymer-ferrocements, and artificial woods.
