Download or read book Effect of Chemical Admixtures on Rheology of Cement Paste at High Temperature written by S. Al-Martini and published by . This book was released on 2007 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Placement of cement-based materials in hot weather conditions encounters many problems due to the rapid evaporation of mixing water and the accelerated hydration of cement. Such materials are also adversely affected at elevated temperatures by an increased water demand, shorter setting time, and more rapid slump loss. These problems can be mitigated using adequate chemical admixtures. However, technical data on such admixtures are commonly developed at normal temperatures, and there is a real need to investigate their performance at hot temperatures. In the current research, the rheological properties of portland cement pastes with a water-cement ratio (w/c) of 0.35 and 0.50 are investigated at different temperatures in the range of 20 to 45°C using an advanced shear-stress/shear-strain controlled rheometer. The influence of water-reducing and retarding admixture, polycarboxylate, naphthalene sulfonate, and melamine-based high-range water-reducing admixtures (HRWR) in addition to mid-range water-reducing admixtures (MRWR) on the rheological properties of cement paste at various temperatures was also examined. The paper aims at formulating recommendations for the effective use of chemical admixtures at high temperature, which should enhance the rheological properties of cement-based materials in hot weather conditions.
Download or read book Study on Microstructure and Rheological Properties of Cement Chemical Admixtures Water Dispersion System at Early Stage written by Yanrong Zhang and published by Springer. This book was released on 2017-07-25 with total page 271 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis studies the effects of superplasticizers, polyacrylate latexes and asphalt emulsions, which differ in molecular/particle size from nanometers to microns, on the rheological properties of fresh cement pastes (FCPs), as well as the action mechanisms involved. It systematically investigates the rheological properties and microstructure of cement-based materials, and elucidates the adsorption behaviors of polycarboxylate polymers with different functional groups and their effects on cement hydration. Moreover, it reveals how the working mechanism of naphthalene sulfonate formaldehyde (NSF) differs from that of polycarboxylate ether-based (PCE) superplasticizers. Lastly, it develops a conceptual microstructure model and two rheological equations. These findings lend theoretical support to the development of new chemical admixtures and new, higher-performance, cement-based composites.
Download or read book Interaction of cement and admixtures and its influence on rheological properties written by Stefan Kubens and published by Cuvillier Verlag. This book was released on 2010-06-14 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Rheology of Fresh Concrete written by G. H. Tattersall and published by Pitman Advanced Publishing Program. This book was released on 1983 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rheology of Fresh Cement and Concrete written by P.F.G. Banfill and published by CRC Press. This book was released on 1990-09-27 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together new research information on the flow behaviour of cementitious materials from the UK, France, Italy, Germany, Poland, Finland, USSR, USA and Japan, presented at the International Conference organised by the British Society of Rheology in March 1990.
Download or read book Rheology of Fresh Cement Based Materials written by Qiang Yuan and published by CRC Press. This book was released on 2022-12-28 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces fundamentals, measurements, and applications of rheology of fresh cement-based materials. The rheology of a fresh cement-based material is one of its most important aspects, characterizing its flow and deformation, and governing the mixing, placement, and casting quality of a concrete. This is the first book to bring the field together on an increasingly important topic, as new types of cement-based materials and new concrete technologies are developed. It describes measurement equipment, procedures, and data interpretation of the rheology of cement paste and concrete, as well as applications such as self-compacting concrete, pumping, and 3D printing. A range of other cement-based materials such as fiber-reinforced concrete, cemented paste backfills, and alkali-activated cement are also examined. Rheology of Fresh Cement-Based Materials serves as a reference book for researchers and engineers, and a textbook for advanced undergraduate and graduate students.
Download or read book Investigation on Rheology of Oil Well Cement Slurries written by Anjuman Shahriar and published by . This book was released on 2011 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rheology of oil well cement (OWC) slurries is generally more complicated than that of conventional cement paste. In order to contend with bottom hole conditions (wide range of pressure and temperature), a number of additives are usually used in the OWC slurries, which exhibit different characteristics depending on the combination of admixture used. The objective of this research is to develop a fundamental understanding of the important mechanisms that affect the rheology of OWC slurry incorporating various chemical and mineral admixtures. The partial replacement of OWC using different mineral admixtures, offers both environmental and economic benefits. The mechanisms underlying the effects of chemical admixtures on the rheology of OWC slurry were investigated at different temperatures using an advanced shear-stress/shear-strain controlled rheometer. The compatibility and interactions between the binder and chemical admixtures were explored. It was found that the rheological properties of OWC slurries are highly dependent on the temperature, water/cement ratio, and the admixture used. Coupled effects of temperature and chemical admixtures had a substantial effect on the flow properties of the slurries. The results indicated that current technical data for chemical admixtures need to be validated for oil well cementing; admixtures proven effective in normal cementing work at moderate temperature may become ineffective for oil well cementing at high temperature. The coupled effects of temperature and supplementary cementing materials (SCMs) on the rheology of OWC slurry were also investigated. Because of differences in their chemical compositions and the mechanisms by which they act, OWC slurries incorporating SCMs exhibit different rheological behaviour than those prepared with pure OWC. It was found that not all SCMs act in similar manner when used as partial replacement for cement. For example, fly ash, owing to its spherical particle shape, reduces the water demand when used. On the other hand, silica fume increased the water demand because of its higher surface area. Results suggested that new generation polycarboxylate-based high-range water reducing admixtures (PCH) improved the rheological properties of all slurries at all temperature tested. However, lower PCH dosage was found to be less efficient in reducing the yield stress or plastic viscosity of OWC slurries when metakaolin (MK) or rice husk ash (RHA) were used as partial replacement for OWC. PCH was found to enhance the shear thickening behaviour of OWC slurries and the intensity of this behaviour varied with the type and amount of SCM. Such a phenomenon was amplified with metakaolin, reduced by SF, unchanged with FA and showed irregular behaviour with RHA. Furthermore, new equations were proposed using multiple regression analysis (MRA) and design of experiments (DOE) to predict the Bingham parameters (yield stress and plastic viscosity) of cement slurries prepared in combination with or without SCMs considering various parameters including the ambient temperature, chemical admixture type and dosage, and superplasticizer type and dosage. An artificial neural network (ANN) model was developed to predict the rheological properties of OWC slurries. The results indicated that the predicted rheological parameters for OWC slurries were in good agreement with corresponding experimental results. However, the ANN-based model performed better than the MRA-based model or DOE-based model in predicting the rheological properties of OWC slurries.
Download or read book Using Cement Paste Rheology to Predict Concrete Mix Design Problems written by Anal K. Mukhopadhyay and published by . This book was released on 2009 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: The complex interaction between cement and chemical/mineral admixtures in concrete mixture sometimes leads to unpredictable concrete performance in the field, which is generally defined as concrete incompatibilities. Cement paste rheology measurements instead of traditional workability tests can have a great potential to detect those incompatibilities in concrete before the concrete is placed to avoid setting time, workability, and curing-related issues, which sometimes leads to severe early-age cracking especially in severe weather conditions. The objective of the present study was to examine the applicability of the Superpave Dynamic Shear Rheometer (DSR) to measure cement paste rheology in one hand and identify cement and mineral/chemical admixtures incompatibilities based on cement paste rheological behavior on the other hand. Based on the extensive laboratory investigation, it is observed that DSR in modified form can measure cement paste rheology with permissible repeatability and sensitivity and has a great potential to identify cement and mineral/chemical admixture incompatibilities. The heat of hydration data from isothermal calorimeter test and setting time results for the studied mixtures have strongly supported the rheology-based observations. A procedure to formulate rheology-based acceptance criteria has been developed based on the available test results. Further refinement of these acceptance criteria based on detailed work covering a wide range of incompatibilities and validation through implementation efforts is warranted. This will ultimately help concrete producers and district laboratories to detect problematic combinations of concrete ingredients during the mixture design process. The researchers also investigated t he feasibility of the mini slump cone test as an alternative or supporting tool for the rheology test.
Download or read book Influence of Mineral Admixtures on the Rheology of Cement Paste and Concrete written by C. F. Ferraris and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Application of Admixtures in Concrete written by A.M. Paillere and published by CRC Press. This book was released on 1994-10-13 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a thorough review of the properties and use of the principal chemical admixtures for use in concrete. Concise and clearly presented, the book includes extensive references to key sources of information. The presentation of each admixture is in a standard format, which helps the reader to find relevant information easily.
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 Chemical Admixtures for Concrete written by Sandra Senft and published by CRC Press. This book was released on 1999-06-24 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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
Download or read book Investigation on Rheology of Cement Paste and Concrete at High Temperature written by Samer Al-Martini and published by . This book was released on 2008 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cemented Paste Backfill written by Yong Wang and published by Elsevier. This book was released on 2024-06-03 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: In view of the demand for the research on the transport resistance characteristics and mechanical properties of CPB under the influence of temperature effect, the book comprehensively describes the studies on rheological and mechanical properties of CPB materials used in underground metal mines. This book covers a wide range of topics, including a new definition of CPB, past participation and flow-induced corrosion of pipeline under the constant temperature condition, multiphysics processes in CPB and the associated consolidation process, the variation of rheological parameters and transport resistance, prediction model for rheological properties, mechanical behavior and properties of CPB and fiber-reinforced CPB, and control technology to reduce the adverse effect of temperature. Therefore, an academic framework for the transport resistance characteristics and mechanical properties under the temperature effect was established in this book. Investigates rheological properties and multiphysics processes in CPB materials around the world Looks into systematic studies on pipe transport and mechanical properties of CPB under temperature effects Focuses mainly on the effect of temperature on paste transport and mechanical properties under the temperature effect, which provides a theoretical basis for safe and efficient filling operation and associated future research in this field Offer in-depth insights into the evolution of the rheological and mechanical properties of CPB under the effect of temperatures
Download or read book Rheology of Fresh Cement Based Materials written by Qiang Yuan and published by CRC Press. This book was released on 2022-12-28 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces fundamentals, measurements, and applications of rheology of fresh cement-based materials. The rheology of a fresh cement-based material is one of its most important aspects, characterizing its flow and deformation, and governing the mixing, placement, and casting quality of a concrete. This is the first book to bring the field together on an increasingly important topic, as new types of cement-based materials and new concrete technologies are developed. It describes measurement equipment, procedures, and data interpretation of the rheology of cement paste and concrete, as well as applications such as self-compacting concrete, pumping, and 3D printing. A range of other cement-based materials such as fiber-reinforced concrete, cemented paste backfills, and alkali-activated cement are also examined. Rheology of Fresh Cement-Based Materials serves as a reference book for researchers and engineers, and a textbook for advanced undergraduate and graduate students.
Download or read book Workability and Quality Control of Concrete written by G H Tattersall and published by CRC Press. This book was released on 2003-09-02 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fresh concrete must be produced with the properties required for its intended applications, for example, it must be workable enough to flow into formwork, and to be compacted. This book deals with the measurement of the flow properties of fresh concrete and the factors which affect its workability. Aspects of concrete mixes and control of manufacture to produce optimum properties which relate to workability are covered.
Download or read book Active Rheology Control of Cementitious Materials written by Geert De Schutter and published by CRC Press. This book was released on 2023-01-18 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reports on cutting-edge research within the new field of active rheology control of cementitious materials, presenting new ideas developed within the ERC Advanced Grant Project, SmartCast (hosted at Ghent University), which extend the possibilities of admixtures and additions beyond current options. The research presented here develops a new method of actively controlling the rheology of fresh concrete during casting operations by incorporating specially designed responsive components. This results in real-time changes to the rheological behaviour of the cementitious material, allowing the user to intervene actively after the cementitious material has left the mixing phase. This newly gained agility contributes to increased processing speed and placement reliability in the case of traditional casting methods and can also facilitate advanced 3D concrete printing. The different routes followed to achieve this Active Rheology Control are explained within. The book suits researchers and innovative practitioners and is the first comprehensive text to present these new findings. The Open Access version of this book, available at http://www.taylorfrancis.com, has been made available under a Creative Commons Attribution-Non Commercial-No Derivatives 4.0 license.
