Early-age Behavior of Calcium Aluminate Cement Systems

Early-age Behavior of Calcium Aluminate Cement Systems
Author: Jason H. Ideker
Publisher:
Total Pages: 592
Release: 2008
Genre: Calcium aluminate
ISBN:

Download Early-age Behavior of Calcium Aluminate Cement Systems Book in PDF, Epub and Kindle

Compared to the knowledge base for ordinary portland cement concrete (OPCC), relatively little information exists for calcium aluminate cement concrete (CACC), despite its existence for over 100 years. There is particularly a lack of knowledge related to early-age behavior of CACC, specifically volume change and cracking potential. To assess these early-age properties, two unique pieces of equipment were developed and employed: a rigid cracking frame and free deformation frame which enabled quantification of restrained stress generation and unrestrained autogenous deformation, respectively. These two pieces of equipment employed active temperature control and allowed a wide range of isothermal and realistic temperature conditions to be imposed upon hydrating cementitious samples. Match-cured samples (i.e. identical temperature curing to that in the frames) enabled the quantification of mechanical property development. Samples cured at discrete isothermal temperatures up to 30 °C developed tensile forces in the rigid cracking frame and exhibited shrinkage phenomena in the free deformation frame. At temperatures above 30 °C, the converse was true and significant compressive forces developed in restrained testing and expansion was observed in unrestrained testing. It was found that this was a direct result of microstructural development related to the formation of metastable phases (associated with shrinkage) and stable phases (expansion as a result of conversion from metastable to stable phases). Proper use of this material must take into account behavior associated with both types of hydrate assemblages, metastable and stable. Realistic time-temperature histories were also investigated based on field-scale concrete cast as part of this research project. It was found that volume change at earlyage was dominantly controlled by thermal history. Furthermore, it was not simply the maximum temperature reached, but the rate of temperature rise during hydration and the resulting duration of time spent at high temperature that profoundly influenced volume change and property development. The research described in this dissertation represents a significant advancement of the state-of-knowledge of this unique material and has further elucidated the role of temperature during hydration of CACC.

Multi-scale Characterization, Implementation, and Monitoring of Calcium Aluminate Cement Based-systems

Multi-scale Characterization, Implementation, and Monitoring of Calcium Aluminate Cement Based-systems
Author: Anthony Frederick Bentivegna
Publisher:
Total Pages: 692
Release: 2012
Genre:
ISBN:

Download Multi-scale Characterization, Implementation, and Monitoring of Calcium Aluminate Cement Based-systems Book in PDF, Epub and Kindle

Calcium aluminate cement (CAC) is a rapid hardening cementitious material often used in niche concrete repairs where high early-age strength and robust durability are required. This research project characterized the implications of the additions of various mineral and chemical admixtures to plain CAC to mitigate strength reductions associated with conversion, an inevitable strength reduction associated with the densification of metastable hydrates (CAH10 and C2AH8) to stable hydrates (C3AH6 and AH3). The effect of these admixtures on early-age strength development, volume change, and the correlation to macro-scale performance were reported in this dissertation. Various mixtures of CAC were investigated including: pure CAC, binary blends of CAC with fly ash (Class C) or CaCO3, and ternary blends of CAC with slag and silica fume. Characterization of the influence of these admixtures on hydration was completed using x-ray diffraction, isothermal calorimetry, and chemical shrinkage. Investigations on the implications of early-age volume change were conducted for autogenous deformation. In addition to laboratory testing, the final phase of the project was to correlate and elucidate the data generated in the laboratory to real-world field performance. Field trials were conducted to evaluate and monitor the behavior of CAC systems and investigate the link between laboratory generated research and actual large scale behavior.

Lea's Chemistry of Cement and Concrete

Lea's Chemistry of Cement and Concrete
Author: Peter Hewlett
Publisher: Butterworth-Heinemann
Total Pages: 896
Release: 2019-03-06
Genre: Technology & Engineering
ISBN: 0081007957

Download Lea's Chemistry of Cement and Concrete Book in PDF, Epub and Kindle

Lea's Chemistry of Cement and Concrete, Fifth Edition, examines the suitability and durability of different types of cements and concretes, their manufacturing techniques and the role that aggregates and additives play in achieving concrete's full potential of delivering a high-quality, long-lasting, competitive and sustainable product. Provides a 60% revision over the fourth edition last published in 2004 Includes updated chapters that represent the latest technological advances in the industry, including, but not exclusive to the production of low-energy cements, cement admixtures and concrete aggregates Presents expanded coverage of the suitability and durability of materials aggregates and additives

Factors Influencing Conversion and Volume Stability in Calcium Aluminate Cement Systems

Factors Influencing Conversion and Volume Stability in Calcium Aluminate Cement Systems
Author: Matthew Peter Adams
Publisher:
Total Pages: 272
Release: 2015
Genre: Alumina cement
ISBN:

Download Factors Influencing Conversion and Volume Stability in Calcium Aluminate Cement Systems Book in PDF, Epub and Kindle

There is renewed interest in North America for the use of calcium aluminate cement (CAC) in infrastructure repair. The interest is driven by the specialty properties that make CAC the ideal candidate for particular applications. These include rapid strength gain, even at temperatures approaching 0°C, the ability to customize fresh property characteristics, high abrasion resistance, and resistance to chemical corrosion. Despite the advantages that CAC can bring to infrastructure repair projects, it is still not well understood within the North American construction community. There are three main topics that are limiting the use of CAC in the construction industry today: (1) a general lack-of-understanding within the construction industry of the conversion process that occurs in CAC systems; (2) there is no standardized accelerated test method for determining the minimum converted strength of CAC concrete; and (3) there are insufficient data on the long-term performance of concrete made with CAC, particularly as a repair material in transportation infrastructure. The work presented in this dissertation addresses these topics in an effort to provide information for and tools for construction professionals interested in using CAC in infrastructure repair situations. Conversion of the hydration products of concrete where CAC is the only binder is a well-known phenomenon which is accompanied by the formation of porosity and strength loss. Presented in this dissertation is an accelerated test method for determining the converted strength of CAC concrete that is convenient for use in the field. Robustness of this test method is examined. The effects of water to cement materials ratio (w/cm), curing temperature during initial 24 hours after casting, length of time prior to being placed in 50°C water bath, and aggregate source are examined. Results indicated that the test method is viable for use in the field, however writing of a standard based on this method will require careful consideration to take into account impact of temperature impact and aggregate source on time to conversion. Variability of the test method between four laboratories was also examined and showed that variability within CAC systems is higher when compared to ordinary portland cement (OPC) systems. Also presented is a study of the impact of replacing CAC with finely ground limestone (FGLS) at rates of 1%, 2%, 5%, and 10%. These results showed that replacement rates up to 5% can significantly improve the converted strength of CAC concrete without impacting rapid strength gain prior to conversion. A further examination of the impact of aggregate type on hydration, conversion, and strength development in CAC systems is also presented. Concrete systems made with nine different coarse aggregate sources and six different fine aggregate sources were cast. Carbonate limestone aggregate systems experienced delayed times to conversion and experienced less strength reduction due to conversion compared to siliceous limestone and siliceous river gravel aggregates. Further examination was done to study the pore solution chemistry, porosity, and microstructure of one carbonate limestone and one siliceous river gravel system. These results indicated that the siliceous river gravel system had lower ionic activity within its pore solution at all ages, and had significantly lower pH compared to the carbonate limestone system. Additionally, the siliceous river gravel system formed poor interfacial transition zones and had higher overall porosity compared to the carbonate limestone system. Theories explaining the differences between these two systems are presented. Finally, an examination of volume stability of CAC systems compared to calcium sulfoaluminate cement (CSA) and OPC systems is presented. Systems based on CAC experienced the highest levels of chemical, autogenous, and drying shrinkage. It was found that the rapid setting nature of CAC and CSA systems caused the pore structures to develop quickly resulting in an increase in the rate of early age shrinkage compared to the OPC system. Additionally, the impact of length of curing on drying shrinkage was examined for CSA and CAC systems. Results showed that length of curing did not impact overall drying shrinkage in either system.

Calcium Aluminate Cements

Calcium Aluminate Cements
Author: R.J. Mangabhai
Publisher: CRC Press
Total Pages: 380
Release: 1990-07-05
Genre: Architecture
ISBN: 9780419152002

Download Calcium Aluminate Cements Book in PDF, Epub and Kindle

The special properties of calcium aluminate cements make them of value in the construction, mining and refractory industries. This book brings together new international research information on their performance. As well as a state-of-the-art review, it includes reports on studies of: mineralogy, hydration and microstructure; rheology of pastes, mortars and grouts; admixtures and blended; systems durability of high alumina cement concrete.

Cement and Concrete Chemistry

Cement and Concrete Chemistry
Author: Wieslaw Kurdowski
Publisher: Springer Science & Business
Total Pages: 705
Release: 2014-04-24
Genre: Science
ISBN: 9400779453

Download Cement and Concrete Chemistry Book in PDF, Epub and Kindle

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.

Innovative Materials for Construction

Innovative Materials for Construction
Author: Mariaenrica Frigione
Publisher: MDPI
Total Pages: 212
Release: 2021-05-05
Genre: Science
ISBN: 3036501665

Download Innovative Materials for Construction Book in PDF, Epub and Kindle

Most of the typical materials employed in today’s constructions present limitations, especially concerning their durability, in either common or severe environmental conditions, and their impact on the environment. In response to these issues, academic and industrial efforts around the world have been devoted to developing new smart materials that can provide efficient alternatives, improve the energy efficiency of buildings, or can upgrade, repair, or protect existing infrastructures. Different and wide technological innovations are, therefore, quickly fostering advancements in the field of construction materials. A new generation of materials (bricks, cement, coatings, concrete, FRP, glass, masonry, mortars, nano-materials, PCM, polymers, steel, wood, etc.) is gaining a prominent position in modern building technology, since they can overcome various limits and flaws of conventional materials employed in constructions, without neglecting the smart applications of pioneering materials in ancient constructions and historic buildings. Even though the adoption of innovative materials in the construction field has been a successful route in achieving enhanced performance, or even new and unexpected characteristics, some issues have not been completely solved. On top of them, the cost/performance ratio of novel solutions, since their introduction must be convenient, without compromising quality. Other concerns are related to their sustainability, with eco-friendly options, possibly exploiting recycled materials or by-products from other productions, being the most desirable solution. Finally, the use of materials or systems that are unconventional in this field raises the need to update or develop new specifications and standards. This special issue aims at providing a platform for discussing open issues, challenges, and achievements related to innovative materials proposed for the construction industry.

Structure and Performance of Cements, Second Edition

Structure and Performance of Cements, Second Edition
Author: P. Barnes
Publisher: CRC Press
Total Pages: 584
Release: 2002-11-01
Genre: Architecture
ISBN: 0203477782

Download Structure and Performance of Cements, Second Edition Book in PDF, Epub and Kindle

Drawing together a multinational team of authors, this second edition of Structure and Performance of Cements highlights the latest global advances in the field of cement technology. Three broad categories are covered: basic materials and methods, cement extenders, and techniques of examination. Within these categories consideration has been given to environmental issues such as the use of waste materials in cement-burning as supplementary fuels and new and improved methods of instrumentation for examining structural aspects and performance of cements. This book also covers cement production, mineralogy and hydration, as well as the mechanical properties of cement, and the corrosion and durability of cementitious systems. Special cements are included, along with calcium aluminate and blended cements together with a consideration of the role of gypsum in cements. Structure and Performance of Cements is an invaluable key reference for academics, researchers and practitioners alike.

Second RILEM International Conference on Concrete and Digital Fabrication

Second RILEM International Conference on Concrete and Digital Fabrication
Author: Freek P. Bos
Publisher: Springer Nature
Total Pages: 1209
Release: 2020-07-08
Genre: Technology & Engineering
ISBN: 3030499162

Download Second RILEM International Conference on Concrete and Digital Fabrication Book in PDF, Epub and Kindle

This book gathers peer-reviewed contributions presented at the 2nd RILEM International Conference on Concrete and Digital Fabrication (Digital Concrete), held online and hosted by the Eindhoven University of Technology, the Netherlands from 6-9 July 2020. Focusing on additive and automated manufacturing technologies for the fabrication of cementitious construction materials, such as 3D concrete printing, powder bed printing, and shotcrete 3D printing, the papers highlight the latest findings in this fast-growing field, addressing topics like mixture design, admixtures, rheology and fresh-state behavior, alternative materials, microstructure, cold joints & interfaces, mechanical performance, reinforcement, structural engineering, durability and sustainability, automation and industrialization.

Low Carbon Stabilization and Solidification of Hazardous Wastes

Low Carbon Stabilization and Solidification of Hazardous Wastes
Author: Daniel C.W. Tsang
Publisher: Elsevier
Total Pages: 592
Release: 2021-09-24
Genre: Science
ISBN: 0128242523

Download Low Carbon Stabilization and Solidification of Hazardous Wastes Book in PDF, Epub and Kindle

Low Carbon Stabilization and Solidification of Hazardous Wastes details sustainable and low-carbon treatments for addressing environmental pollution problems, critically reviewing low-carbon stabilization/solidification technologies. This book presents the latest state-of-the-art knowledge of low-carbon stabilization/solidification technologies to provide cost-effective sustainable solutions for real-life environmental problems related to hazardous wastes including contaminated sediments. As stabilization/solidification is one of the most widely used waste remediation methods for its versatility, fast implementation and final treatment of hazardous waste treatment, it is imperative that those working in this field follow the most recent developments. Low Carbon Stabilization and Solidification of Hazardous Wastes is a necessary read for academics, postgraduates, researchers and engineers in the field of environmental science and engineering, waste management, and soil science, who need to keep up to date with the most recent advances in low-carbon technologies. This audience will develop a better understanding of these low-carbon mechanisms and advanced characterization technologies, fostering the future development of low-carbon technologies and the actualization of green and sustainable remediation. Focuses on stabilization/solidification for environmental remediation, as one of the most widely used environmental remediation technologies in field-scale applications Details the most advanced and up-to-date low-carbon sustainable technologies necessary to guide future research and sustainable development Provides comprehensive coverage of low-carbon solutions for treating a variety of hazardous wastes as well as contaminated soil and sediment