Cement Based Materials

Concrete and cement-based materials must operate in increasingly aggressive aqueous environments, which may be either natural or industrial. These materials may suffer degradation in which ion addition and/or ion exchange reactions occur, leading to a breakdown of the matrix microstructure and consequent weakening. Sometimes this degradation can be extremely rapid and serious such as in acidic environments, while in other cases degradation occurs over long periods. Consequences of material failure are usually severe – adversely affecting the health and well-being of human communities and disturbing ecological balances. There are also large direct costs of maintaining and replacing deteriorated infrastructure and indirect costs from loss of production during maintenance work, which place a great burden on society. The focus of this book is on addressing issues concerning performance of cement-based materials in aggressive aqueous environments , by way of this State-of-the-Art Report. The book represents the work of many well-known and respected authors who contributed chapters or parts of chapters. Four main themes were addressed: I. Nature and kinetics of degradation and deterioration mechanisms of cement-based materials in aggressive aqueous environments, II. Modelling of deterioration in such environments, III. Test methods to assess performance of cement-based materials in such environments, and which can be used to characterise and rate relative performance and inform long term predictions, IV. Engineering implications and consequences of deterioration in aggressive aqueous environments, and engineering approaches to the problem.

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.

Waste and By-Products in Cement-Based Materials: Innovative Sustainable Materials for a Circular Economy covers various recycled materials, by-products and wastes that are suitable for the manufacture of materials within the spectrum of so-called cement-based materials (CBM). Sections cover wastes for replacement of aggregates in CBM, focus on the application of wastes for the replacement of clinker and mineral additions in the manufacture of binders, discuss the optimization process surrounding the manufacture of recycled concrete and mortars, multi-recycling, advanced radiological studies, optimization of self-compacting concrete, rheology properties, corrosion prevention, and more. Final sections includes a review of real-scale applications that have been made in recent years of cement-based materials in roads, railway superstructures, buildings and civil works, among others, as well as a proposal of new regulations to promote the use of waste in the manufacture of CBM. Favors the institution of the circular economy in the construction industry by eliminating the barriers that currently prevent industrial waste from being valorized by its inclusion in CBM design Features an in-depth exploration of the strengths and weaknesses of new raw materials and their application to CBMs Features real-scale applications that have been made in recent years of cement-based materials in roads, railway superstructures, buildings and civil works, among others Presents current, state-of-the-art, and future-prospects for the use of industrial waste in CBMs

The book examines advanced, non-standardized techniques that have been developed for determining different properties of cement paste, mortar and concrete, and provides state-of-the-art information on methods for monitoring hydration-induced changes in cement-based materials (CBMs). These methods are often nondestructive and allow quasi-continuous monitoring covering the time span from placement of the material to formation of a fully hardened cement composite. The book also presents various applications of acoustic emission for characterizing fresh concrete, recent developments in ultrasonic methods for characterizing CBMs since placement, application of ambient response methods for measuring elastic modulus, methods for determining deformational characteristics of CBMs since setting and methods for in situ measurements of stresses in concrete elements during hardening.

As the re-emergence of nuclear power as an acceptable energy source on an international basis continues, the need for safe and reliable ways to dispose of radioactive waste becomes ever more critical. The ultimate goal for designing a predisposal waste-management system depends on producing waste containers suitable for storage, transportation and permanent disposal. Cement-Based Materials for Nuclear-Waste Storage provides a roadmap for the use of cementation as an applied technique for the treatment of low- and intermediate-level radioactive wastes. Coverage includes, but is not limited to, a comparison of cementation with other solidification techniques, advantages of calcium-silicate cements over other materials and a discussion of the long-term suitability and safety of waste packages as well as cement barriers.

Cement-Based Composites takes a different approach from most other books in the field by viewing concrete as an advanced composite material, and by considering the properties and behaviour of cement-based materials from this stance. It deals particularly, but not exclusively, with newer forms of cement-based materials. This new edition takes a critical approach to the subject as well as presenting up-to-date knowledge. Emphasis is given to non-conventional reinforcement and design methods, problems at the materials' interfaces and to the durability of structures. High strength composites and novel forms of cement-based composites are described in detail. After a basic introduction the book explores the various components of these materials and their properties. It then deals with mechanical properties and considers characteristics under various loading and environmental conditions, and concludes by examining design, optimization and economics with particular emphasis on high-performance concretes. Researchers, graduate students and practising engineers will find this book valuable.

Self-healing materials are man-made materials which have the built-in capability to repair damage. Failure in materials is often caused by the occurrence of small microcracks throughout the material. In self-healing materials phenomena are triggered to counteract these microcracks. These processes are ideally triggered by the occurrence of damage itself. Thus far, the self-healing capacity of cement-based materials has been considered as something "extra". This could be called passive self-healing, since it was not a designed feature of the material, but an inherent property of it. Centuries-old buildings have been said to have survived these centuries because of the inherent self-healing capacity of the binders used for cementing building blocks together. In this State-of-the-Art Report a closer look is taken at self-healing phenomena in cement-based materials. It is shown what options are available to design for this effect rather than have it occur as a "coincidental extra".

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.