Download or read book Early Age Hydration Studies of Portland Cement written by Fengjuan Liu and published by . This book was released on 2014 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our current knowledge on cement hydration during setting is based on the discrete observation of hydrated paste. An advanced micro/nano-level technique which can perform the in-situ observation on the continuous hydration of cement paste is demanded. In this study, Raman spectroscopy (RS) was chosen as such a method to continuously investigate wet pastes. The objective of this research is to explore the hydration process and microstructural development of fresh pastes with this technique. This research was conducted in three phases. First, the RS analysis was used to continuously observe the cement hydration from 20 minutes after mixing to 9 hours. Based on the analysis, it was found that RS was able to characterize both the cement ingredient (C3S, C2S, C3A, and gypsum) and hydration products (C-S-H gel, CH, ettringite, and monosulfate). The evolution of these components during the setting period was also detected by RS. The obtained Raman signals can indicate the end of the dormant period and initial setting in the cement paste. The RS was then expanded to study the differences in the hydration mechanisms of hardened ordinary cement paste and ultra-high performance concrete (UHPC). The silica fume included into the UHPC was found to react quickly during the first two weeks. The content changes of calcium silicates, calcium hydroxide (CH), and ettringite were different in the ordinary paste and UHPC. In the third phase, Raman chemical mapping was implemented on the hardened cement paste to explore the microstructure developments during the hydration process. A mapping protocol was developed. The obtained maps were able to correctly reflect the distributions and connections of the different paste components. From the mapping study on the cement paste, it was found that ettringite tended to locate on the surface of calcium silicates, while CH was apt to concentrate and localize in the pores as big crystals.
Download or read book Cement Hydration Reactions at Early Ages written by George J. Verbeck and published by . This book was released on 1965 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure and Performance of Cements Second Edition written by P. Barnes and published by CRC Press. This book was released on 2002-11-01 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Nanotechnology in Construction written by Konstantin Sobolev and published by Springer. This book was released on 2015-05-07 with total page 491 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanotechnology has already demonstrated surprising potential for improving the performance of construction materials and many of these recent developments were facilitated by NICOM symposia. The NICOM5 proceedings will cover the emerging opportunities and future use of nanotechnology in construction and will illustrate the broad potential for application of nanotechnology to challenging problems involving materials and infrastructure.
Download or read book Nanotechnology in Construction written by Zdenek Bittnar and published by Springer Science & Business Media. This book was released on 2009-04-21 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 3rd International Symposium on Nanotechnology in Construction (NICOM 3) follows the highly successful NICOM 1 (Paisley, UK 2003) and NICOM 2 (Bilbao, Spain 2005) Symposia. The NICOM3 symposium was held in Prague, Czech Republic from May 31 to June 2, 2009 under the auspices of the Czech Technical University in Prague. It was a cross-disciplinary event, bringing together R&D experts and users from different fields all with interest in nanotechnology and construction. The conference was aimed at: Understanding of internal structures of existing construction materials at nano-scale Modification at nano-scale of existing construction materials. Production and properties of nanoparticulate materials, nanotubes and novel polymers. Modeling and simulation of nanostructures. Instrumentation, techniques and metrology at nano-scale. Health and safety issues and environmental impacts related to nanotechnology during research, manufacture and product use. Review of current legislation. Societal and commercial impacts of nanotechnology in construction, their predictions and analysis.
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 CIGOS 2019 Innovation for Sustainable Infrastructure written by Cuong Ha-Minh and published by Springer Nature. This book was released on 2019-10-10 with total page 1264 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents selected articles from the 5th International Conference on Geotechnics, Civil Engineering Works and Structures, held in Ha Noi, focusing on the theme “Innovation for Sustainable Infrastructure”, aiming to not only raise awareness of the vital importance of sustainability in infrastructure development but to also highlight the essential roles of innovation and technology in planning and building sustainable infrastructure. It provides an international platform for researchers, practitioners, policymakers and entrepreneurs to present their recent advances and to exchange knowledge and experience on various topics related to the theme of “Innovation for Sustainable Infrastructure”.
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 Study of hydration processes of Portland cements blended with supplementary cementitious materials written by Axel Schöler and published by GRIN Verlag. This book was released on 2012-08-16 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Master's Thesis from the year 2012 in the subject Chemistry - Materials Chemistry, grade: 1,3, TU Bergakademie Freiberg (Institut für Glas, Keramik und Baustofftechnik), course: Bauchemie, language: English, abstract: The production of Portland cement clinker has a share of about 6% to 8% on the global CO2-emissions . Approximately 60% of those emissions are attributable to the decarbonation of limestone. A widespread approach for the reduction of the CO2-emissions is to replace the clinker in the cement by pozzolanic waste materials, e.g. fly ash. The reaction of fly ash is generally slow. Due to this slow reaction cement pastes mixed of Portland cement and fly ash have a slower strength development than pure Portland cement, at least at early ages up to 7 days. The goal of this study was to increase early strength properties of Portland cement/fly ash blends by increasing the early ettringite formation in order to decrease the porosity. Therefore various amounts of anhydrite and laboratory synthesised C3A were added to Portland cement/fly ash systems that contained 30% fly ash. The behavior of these systems in terms of kinetics, phase development and microstructure was studied by means of strength tests, isothermal calorimetry, thermogravimetric analysis, chemical shrinkage, X-ray diffraction, backscattered electron image analysis, mercury intrusion porosimetry and thermodynamic modeling. In addition the activation by Na2SO4 was investigated on certain systems. It was found that the amount of ettringite formed increases gradually with increasing amounts of anhydrite and C3A. The formation of ettringite was completed at approximately 1 day. Further the activation with Na2SO4 increased the amount of ettringite and shifted the completion of its formation to approximately 2 days. Due to the addition of anhydrite and C3A the porosity decreased corresponding to the amount of ettringite formed. The effects on the development of early strength were most distinct for very high additions and for systems activated by Na2SO4. All systems showed equal strengths at 7 d and 28 d. For later ages up to 90 days, the benefits at early ages were found to be inversed, leading to lower strength values compared to systems without or with low additions of anhydrite, C3A or Na2SO4. Eventually the increase in early strength was either too low to be significant or only relevant at very high additions of anhydrite and C3A with simultaneous system activation by Na2SO4. In terms of kinetics a remarkable impact of the added C3A was observed as this seemed to significantly accelerate the silicate reaction of the Portland cement.
Download or read book Thermal Cracking in Concrete at Early Ages written by R. Springenschmid and published by CRC Press. This book was released on 1994-10-13 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Restraint and intrinsic stresses in concrete at early ages are vitally important for concrete structures which must remain free of water-permeable cracks, such as water-retaining structures, tunnel linings, locks and dams. The development of hydration heat, stiffness and strength, also the degree of restraint and, especially for high-strength concrete, non-thermal effects, are decisive for sensitivity to cracking. Determining thses stresses in the laboratory and in construction components has led to a clearer understanding of how they develop and how to optimize mix design, temperature and curing conditions. New testing equipment has enabled the effects of all the important parameters to be qualified and more reliable models for predictiong restraint stresses to be developed. Thermal Cracking in Conrete at Early Ages contains 56 contributions by leading international specialists presented at the RILEM Symposium held in October 1994 at the Technical University of Munich. It will be valuable for construction and site engineers, concrete technologists and scientists.
Download or read book Tailor Made Concrete Structures written by Joost C. Walraven and published by CRC Press. This book was released on 2008-05-01 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years knowledge of concrete and concrete structures has increased, as has its applications. New types of concrete challenged scientists and engineers, and ecological constraints encouraged the implementation of life cycle design of concrete structures, moving the focus more and more to maintenance and uprating of structures. And since bui
Download or read book Exploratory Studies of Early Strength Development in Portland Cement Pastes and Mortars written by Raymond Leonard Blaine and published by . This book was released on 1970 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluating the Performance of Portland Cement Under Differing Hydration Conditions written by Charles A. Ishee and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this work was to examine the hydration performance of Portland cement with variations in their Tricalcium Silicate and Tricalcium Aluminate phases. The performance of Portland cement is affected by its particle size, chemistry, morphology, water availability, thermodynamic reaction rates, and age at which the materials are tested. The majority of research on Portland cement hydration has thus far evaluated each of its different components independently by examining how those phases react with water over time. However, Portland cement has many phases that are all reacting simultaneously depending on many different factors. How the different phases react while part of the entire system, including how their reactions affect the reactions of other components in the system, needs to be further investigated in order to determine how a true cement can be expected to behave during hydration. Laboratory research focused on the establishment of early age ...
Download or read book Rheology written by Rajkumar Durairaj and published by BoD – Books on Demand. This book was released on 2013-02-13 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the current research in the area of rheology. Rheological characterizations are performed on materials in order to understand the basic nature of a system, quality control of raw materials and final products. The rheological characterizations are important to study the effect of different parameters such as formulation, shelf life and temperature on the quality of final products. The book covers a broad range of rheology related topics such as microrheology, capillary rheolgical measurements, characterization of dense suspensions and numerical analysis of viscoelastic fluids.
Download or read book Cement Production Technology written by Anjan Kumar Chatterjee and published by CRC Press. This book was released on 2018-04-27 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is an outcome of the author’s active professional involvement in research, manufacture and consultancy in the field of cement chemistry and process engineering. This multidisciplinary title on cement production technology covers the entire process spectrum of cement production, starting from extraction and winning of natural raw materials to the finished products including the environmental impacts and research trends. The book has an overtone of practice supported by the back-up principles.
Download or read book Application of Super Absorbent Polymers SAP in Concrete Construction written by Viktor Mechtcherine and published by Springer Science & Business Media. This book was released on 2012-01-03 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the state-of-the-art report prepared by the RILEM TC “Application of Super Absorbent Polymers (SAP) in concrete construction”. It gives a comprehensive overview of the properties of SAP, specific water absorption and desorption behaviour of SAP in fresh and hardening concrete, effects of the SAP addition on rheological properties of fresh concrete, changes of cement paste microstructure and mechanical properties of concrete. Furthermore, the key advantages of using SAP are described in detail: the ability of this material to act as an internal curing agent to mitigate autogenous shrinkage of high-performance concrete, the possibility to use SAP as an alternative to air-entrainment agents in order to increase the frost resistance of concrete, and finally, the benefit of steering the rheology of fresh cement-based materials. The final chapter describes the first existing and numerous prospective applications for this new concrete additive.
Download or read book Shotcrete written by E.S. Bernard and published by CRC Press. This book was released on 2020-12-17 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: A reference for shotcrete technologists and practitioners on this method of concrete placement and its great scope for adaptability, optimization, and error. The text assesses laboratory research projects and also focusses on innovative developments in this field.
