The effects of aggregates characteristics on the performance of Portland cement concrete
Author: Pedro Nel Quiroga and David W. Fowler | Size: 7.5 MB | Format:PDF | Publisher: The University of Texas at Austin | Year: 2004 | pages: 382
Aggregate shape, texture, and grading have a significant effect on the performance of fresh concrete. Aggregate blends with well-shaped, rounded, and smooth particles require less paste for a given slump than blends with flat, elongated, angular, and rough particles. At the same time, uniform gradings with proper amounts of each size result in aggregate blends with high packing and in concrete with low water demand. Optimized aggregate blends have high packing, requiring low amounts of paste. As a result, they are less expensive and will have less durability problems caused by the paste such as heat generation, porosity, and drying shrinkage.
Current ASTM C 33 standard limits the amount of material passing the N 200 sieve (microfines) to 7 percent. However, manufactured fine aggregate (MFA) usually has between 10 and 20 percent microfines. These limits, intended for natural sands, force MFA producers to wash aggregate incrementing costs and generating environmental issues. Research at The University of Texas and experience in other countries show that good quality concrete can be made with MFA with high-microfines content.
Many proportioning methods such as ACI 211 do not consider high amounts of microfines, considers partially the effect of shape and texture of aggregates, and do not encourage optimization of aggregate.
The effect of shape, texture and grading of aggregates on fresh concrete was evaluated experimentally, quantified by means a proportioning method based on packing density concepts, the Compressible Packing Model (CPM), and analyzed by an empirical tool suggested by Shilstone. The effect of different types and amounts of microfines was evaluated simultaneously as well as the impact of chemical admixtures and supplementary cementing materials on concrete with high microfines were also evaluated experimentally. It was concluded that chemical admixtures and some supplementary cementing materials can be used to improve the workability of concrete with high microfines without negatively affecting hardened
concrete.
Guidelines for proportioning and optimizing aggregate blends were made based on Shilstone’s Coarseness Chart and the 0.45 Power Chart and CPM equations and procedures.
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Advanced Dynamics of Marine Structures (Ocean engineering)-J.P. Hooft
I borrow the copy of this valuable book from Sharif university then I scanned it in 200 dpi ,though its in poor condition but it still useful.
Hardcover: 364 pages
Publisher: John Wiley & Sons Inc (October 6, 1982)
Language: English
ISBN-10: 0471030007
ISBN-13: 978-0471030003
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Recent research developments in stability and ductility of steel bridge structures
Journal of Constructional Steel Research
Volume 55, Issues 1-3, July 2000, Pages 183-209
Abstract
Some ductility and strength researches of thin-walled steel bridge structures recently conducted at Nagoya University are summarized in this paper. The first part is on the investigations of the behavior of component plates, which are subjected to compression or shear. Both the monotonic and cyclic loading conditions have been considered. Then the studies of stub-columns under combined action of compression and bending are presented. The considered stub-columns are composed of stiffened and unstiffened box sections or pipe sections. For both the plates and stub-columns, empirical equations of strength and ductility have been developed. Based on the equations, a simple ductility evaluation method for thin-walled steel structures which involves a nonlinear pushover analysis and a definition of failure criterion is finally proposed. Moreover, some recent results of thin-walled structures through cyclic experimental and numerical studies are also included in this paper and are compared with the ductility estimations through the proposed simple method.
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This European Standard provides a framework for the specification of hard industrial bitumens used mainly in
flooring, varnishes, mineral rubber, roofing and mastic.
Within Europe several types of hard industrial bitumen are used, and dependent upon traditional practices,
different grades may be used for the same purpose. The framework given in this European standard provides
a basis for quality agreements to be established between supplier and client.
The hard industrial bitumen products are graded by the limits of the ring and ball softening point values,
expressed as multiples of 5, and are characterised by an H in front of the values.
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Strength Measurements Using Maturity for Portland Cement Concrete Pavement Construction at Airfields
Author: Dr. Robert O. Rasmussen, P.E., Dr. James K. Cable, P.E. | Size: 5 MB | Format:PDF | Publisher: The Transtec Group, Inc. | Year: 2003 | pages: 99
This report has been prepared for the Federal Aviation Administration by the
Innovative Pavement Research Foundation under the Airport Concrete
Pavement Technology Program. Funding is provided by the Federal Aviation
Administration under Cooperative Agreement Number 01-G-002. Dr. Satish
Agrawal is the Manager of the FAA Airport Technology R&D Branch and the
Technical Manager of the Cooperative Agreement. Mr. Jim Lafrenz is the IPRF
Cooperative Programs Manager.
The Innovative Pavement Research Foundation and the Federal Aviation
Administration thank the Technical Panel that willingly gave of their expertise and
time for the development of this report. They were responsible for the oversight
and the technical direction. The names of those individuals on the Technical
Panel follow.
Mr. Gerald Voigt, P.E. American Concrete Pavement Association
Mr. Thomas J. Yager NASA Langley Research Center
Mr. Michael A. Shayeson President, The Harper Company
Mr. Wayne Seiler, P.E. All About Pavements, Inc.
Mr. Robert “Murphy” Flynn FAA, Project Technical Advisor
The project team would also like to thank the following individuals and
organizations for their assistance during this effort:
• Des Moines International Airport, Des Moines, Iowa, especially Mr. Robert
M. Krasicki, Senior Operations Officer – Security
• Flynn Company, Inc., Dubuque, Iowa, especially Mr. Mike Flynn, Vice
President and Mr. Mark Gorton, Supervisor
• Iowa Concrete Paving Association, especially Mr. Gordon Smith, P.E.,
President
• Nomadics Construction Labs, Stillwater, Oklahoma, especially Dr. Steven
M. Trost, P.E., Chief Scientist and Mr. Michael Fox, President
• Identec Solutions, Inc. of Kelowna, British Columbia (Canada), especially
Mr. Barry Allen, Vice President of Technology
• Dallas Semiconductor / MAXIM of Dallas, Texas, especially Mr. John S.
Young, iButton Channel Manager – Americas
• Point Six, Inc. of Lexington, Kentucky, especially Mr. Dan Piroli, Vice
President and Messrs. Paul Hill and Tim Harover, Engineering
• Mr. Michael Anthony, Graduate Research Assistant, Iowa State University
The contents of this report reflect the views of the authors who are responsible
for the facts and the accuracy of the data presented within. The contents do not
necessarily reflect the official views and policies of the Federal Aviation
Administration. This report does not constitute a standard, specification, or
regulation.
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The syllabi for training courses that cover the conventional NDT methods are available in IAEA-TECDOC-628. This TECDOC covers the conventional methods of liquid penetrant testing, magnetic particle testing, eddy current testing, radiographic testing, ultrasonic testing, visual inspection and leak testing. Based on these syllabi, training course notes have been produced to cover Industrial Radiography (IAEA Training Course Series No. 3) and Ultrasonic Testing of Materials at Level 2 (IAEA Training Course Series No. 10). These training course notes deal predominantly with the NDT of metallic materials. While NDT of metallic materials is a very important application, NDT is being used increasingly for the inspection of concrete structures. Training Course Series Nos. 3 and 10 cover the inspection of concrete using the relevant NDT method; however, coverage is brief and does not present the whole range of NDT methods used for the NDT of concrete. Concrete has become a very common construction material in most IAEA Member States and problems have occurred because of faulty construction practice. A need was therefore identified for a guidebook on the NDT of concrete. The first IAEA Training Course on the NDT of Concrete and other Non-Metallic Materials was held in 1987 in Japan, at the Japanese Society for Non-Destructive Inspection. Subsequent courses/workshops were held in Thailand and Singapore. In 1998, AFRA national co-ordinators prepared a draft syllabus on the NDT of Concrete. This syllabus was circulated for comment to national co-ordinators in other IAEA projects. R.S. Gilmour (Australia) compiled the first draft of the training material, which was circulated to the national NDT co-ordinators for the NDT subproject in different RCA countries. IAEA experts discussed the amendments made to this draft at a Meeting on the NDT of concrete in the Malaysian Institute for Nuclear Technology (MINT), Malaysia in September 1999. During the compilation of this manuscript, guidance and support were provided by Abd Nassir Ibrahim from Malaysia and G. Singh from India. The IAEA officer responsible for this publication was A.A. Khan of the Division of Physical and Chemical Sciences.
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Guide to the LEED Green Associate Exam
Author: Michelle Cottrell
ISBN: 9780470608296
Paperback
208 pages
September 2010
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------------------- Moderator Note: - Transparent links are not allowed, use coded links
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