Geopolymer is an amorphous aluminosilicate binder which is produced by hydrothermal synthesis of aluminosilicates in the presence of concentrated alkaline or alkaline silicate solutions. It is an emerging construction material purported to provide an environmentally-friendly alternative to ordinary Portland cement (OPC) based concrete. Owing to its ceramic-like properties, geopolymer has been touted to be a highly fire resistant material. This claim is further supported by results from investigations of residual strength after thermal exposure. Some studies have found that geopolymers increase in strength after exposure to temperatures of 800°C. In contrast, several recent studies have shown a decrease in residual strength of geopolymers after a similar exposure. These contradictory observations are explored here. The study shows that two opposing processes are occurring simultaneously in geopolymers at elevated temperatures. Process (1) is further geopolymerization, and has the effect of increasing the strength. Process (2) is the damage due to thermal incompatibility which arises because of (i) the temperature gradient and (ii) different movements between matrix and inclusions. Process (2) is also a function of the brittleness level of the material. Whether the strength increases or decreases is dependent on which of the two processes is dominant in the specimen and the test conditions.The detailed examination of process (2) reveals a strong correlation between the degree of strength loss and the brittleness of geopolymers. This correlation suggests that geopolymers are quite brittle. For the first time, the brittleness of geopolymer concrete has been quantitatively determined and compared with OPC concrete. The comparatively high brittleness of geopolymer concrete is important for its fire resistance properties. The high brittleness will also require special structural design measures, similar to the design requirements for high strength concrete. With regard to the fire resistance of geopolymers, most research to date has investigated only residual strength, but the properties of geopolymer while hot have received less attention. Therefore, a number of tests to determine stress-strain curve, ultimate strength, elastic modulus and creep were undertaken in steady and transient heating conditions. In these tests, several critical features of the material's performance were observed: (1) geopolymers exhibit glass transition behaviour at elevated temperatures; (2) glass transition temperature is improved by the substitution of a sodium-based activator for the potassium-based activator; (3) below glass transition temperature there is a significant increase in hot strength and hot elastic modulus; (4) in the range of 250-550°C thermal transitional creep is absent as compared to OPC concrete. Data obtained from these measurements can serve as input for the development of constitutive models which are essential to predict the response of geopolymer concrete elements in fire. In addition to its deteriorating properties at high temperatures, concrete can also be damaged in fire by a phenomenon called spalling, which is particularly severe in high strength concrete. Since geopolymer is comparatively more brittle than high strength concrete, the issue of spalling in fire is further explored in the last part of this study. It was found that the spalling resistance of geopolymer concrete increases as maximum aggregate size increases. The increasing aggregate size results in an increase in fracture zone length (lp); this in turn reduces the flux of kinetic energy (due to pore pressure) that is released into the fracture front and thereby improves spalling resistance. This theory is further validated by the observation of a good correlation between lp and spalling resistance in this thesis. This study is the first to propose such a hypothesis on the effect of aggregate size on the spalling of concrete, both OPC and geopolymer, and contributes to a better understanding of spalling of concrete in fire.

This is a State of the Art Report resulting from the work of RILEM Technical Committee 224-AAM in the period 2007-2013. The Report summarises research to date in the area of alkali-activated binders and concretes, with a particular focus on the following areas: binder design and characterisation, durability testing, commercialisation, standardisation, and providing a historical context for this rapidly-growing research field.

Geopolymers presents a complex and interdisciplinary study in the fields of physics, chemistry, materials science, and civil engineering on oxide materials based on mineral wastes, known as geopolymers. Considering the ideal requirements for developing eco-friendly materials for industrial applications, this book describes how to design and develop different types of geopolymers that use mineral wastes or natural aluminosilicates as raw materials. It contains advanced knowledge and information regarding geopolymer manufacturing, development, characterization, and applications in soil stabilization, civil engineering, or ceramics. This book is relevant for undergraduate and graduate students conducting fundamental and applied research in the fields of materials engineering, ceramics engineering, and water processing.

A geopolymer is a solid aluminosilicate material usually formed by alkali hydroxide or alkali silicate activation of a solid precursor such as coal fly ash, calcined clay and/or metallurgical slag. Today the primary application of geopolymer technology is in the development of reduced-CO2 construction materials as an alternative to Portland-based cements. Geopolymers: structure, processing, properties and industrial applications reviews the latest research on and applications of these highly important materials.Part one discusses the synthesis and characterisation of geopolymers with chapters on topics such as fly ash chemistry and inorganic polymer cements, geopolymer precursor design, nanostructure/microstructure of metakaolin and fly ash geopolymers, and geopolymer synthesis kinetics. Part two reviews the manufacture and properties of geopolymers including accelerated ageing of geopolymers, chemical durability, engineering properties of geopolymer concrete, producing fire and heat-resistant geopolymers, utilisation of mining wastes and thermal properties of geopolymers. Part three covers applications of geopolymers with coverage of topics such as commercialisation of geopolymers for construction, as well as applications in waste management.With its distinguished editors and international team of contributors, Geopolymers: structure, processing, properties and industrial applications is a standard reference for scientists and engineers in industry and the academic sector, including practitioners in the cement and concrete industry as well as those involved in waste reduction and disposal. - Discusses the synthesis and characterisation of geopolymers with chapters covering fly ash chemistry and inorganic polymer cements - Assesses the application and commercialisation of geopolymers with particular focus on applications in waste management - Reviews the latest research on and applications of these highly important materials

The book covers the topic of geopolymers, in particular it highlights the relationship between structural differences as a result of variations during the geopolymer synthesis and its physical and chemical properties. In particular, the book describes the optimization of the thermal properties of geopolymers by adding micro-structural modifiers such as fibres and/or fillers into the geopolymer matrix. The range of fibres and fillers used in geopolymers, their impact on the microstructure and thermal properties is described in great detail. The book content will appeal to researchers, scientists, or engineers who are interested in geopolymer science and technology and its industrial applications.

Recent Developments of Geopolymer Materials: Processing and Characterisations focuses on the development, processing, and characterization of sustainable and eco-friendly materials, highlighting recent research developments in this field. The book covers the processing and characterization of geopolymers, incorporating green materials from waste and recycled materials specifically for construction applications, as well as advanced processing and characterization for a wide variety of applications. The book provides in-depth chapters on the development, processing, and characterization of sustainable and green materials with extensive uses, such as construction.It is divided into two sections: Development of Geopolymer Materials for Construction Applications and Advanced Processing and Characterization for Wider Applications, and will be a useful resource for academics, engineers, companies, and stakeholders in geopolymers from green materials for a variety of wide applications, including construction materials, ceramics, adsorbents, drilling properties, and simulation analysis. - Provides new knowledge and the latest technology and research relating to the processing and characterization of geopolymers incorporating green materials from waste and recycled materials - Covers the latest research on variety of wide applications, including construction materials, ceramics, adsorbents, drilling properties, and simulation analysis - Includes in-depth coverage of the benefits of geopolymer technology

Geopolymers presents a complex and interdisciplinary study in the fields of physics, chemistry, materials science, and civil engineering on oxide materials based on mineral wastes, known as geopolymers. Considering the ideal requirements for developing eco-friendly materials for industrial applications, this book describes how to design and develop different types of geopolymers that use mineral wastes or natural aluminosilicates as raw materials. It contains advanced knowledge and information regarding geopolymer manufacturing, development, characterization, and applications in soil stabilization, civil engineering, or ceramics. This book is relevant for undergraduate and graduate students conducting fundamental and applied research in the fields of materials engineering, ceramics engineering, and water processing.

This book investigates geopolymers and geopolymer-based composites, with a focus on their preparation, geopolymerization mechanisms, microstructures, mechanical properties, and fracture behaviors. Geopolymers are inorganic materials consisting of tetrahedral units (such as [SiO4] and [AlO4]) linked by shared oxygens and forming long-range, covalently bonded and amorphous frameworks. Geopolymers have the advantages of low-temperature preparation, low cost, high heat and corrosion resistance, and being environmentally friendly. Using the preparation methods for epoxy-based composite, they can easily be formed into complex shapes or structures. Intended for researchers investigating geopolymers and their matrix composite materials, this book is also a valuable resource for engineers from various fields, such as materials, mechanical, civil and structural engineering, as well as students interested in other kinds of inorganic materials or even cementitious materials in general.

Pore Structure of Cement-Based Materials provides a thorough treatment of the experimental techniques used to characterize the pore structure of materials. The text presents the principles and practical applications of the techniques used, organized in an easy-to-follow and uncomplicated manner, providing the theoretical background, the way to analyze experimental data, and the factors affecting the results. The book is the single comprehensive source of the techniques most commonly used for pore structure analysis, covering simple techniques like mercury intrusion porosimetry and water absorption, to the more sophisticated small-angle scattering and nuclear magnetic resonance. The book is an essential reference text for researchers, users, and students in materials science, applied physics, and civil engineering, who seek a deep understanding of the principles and limitations of the techniques used for pore structure analysis of cement-based materials.