he objectives of cold weather concreting practices are to prevent damage to concrete due to freezing at early ages, ensure that the concrete develops the required strength for safe removal of forms, maintain curing conditions that foster normal strength development, limit rapid temperature changes, and provide protection consistent with the intended serviceability of the structure.
Concrete placed during cold weather will develop sufficient strength and durability to satisfy intended service requirements when it is properly produced, placed, and protected. This guide provides information for the contractor to select the best methods to satisfy the minimum cold weather concreting requirements.
This guide discusses: concrete temperature during mixing and placing, temperature loss during delivery, preparation for cold weather concreting, protection requirements for concrete that does not require construction supports, estimating strength development, methods of protection, curing requirements, and admixtures for accelerating setting and strength gain including antifreeze admixtures. The materials, processes, quality control measures, and inspections described in this document should be tested, monitored, or performed as applicable only by individuals holding the appropriate ACI Certifications or equivalent.
Keywords: accelerating admixtures; antifreeze admixtures; cold weather concreting; concrete temperature; curing; enclosures; form removal; freezing and thawing; heaters; heating aggregates; insulating materials; maturity testing; protection; strength development.
Contents: Chapter 1—Introduction, p. 2
Chapter 2—Notation and definitions, p. 2
2.1—Notation
2.2—Definitions
Chapter 3—Objectives, principles, and economy,p. 3
3.1—Objectives
3.2—Principles
3.3—Economy
Chapter 4—General requirements, p. 4
4.1—Planning
4.2—Protection during unexpected freezing
4.3—Concrete temperature
4.4—Temperature records
4.5—Heated enclosures
4.6—Finishing air-entrained slabs
4.7—Concrete workability
Chapter 5—Temperature of concrete as mixed and placed, and heating of materials, p. 5
5.1—Placement temperature
5.2—Mixing temperature
5.3—Heating mixing water
5.4—Heating aggregates
5.5—Steam heating of aggregates
5.6—Overheating of aggregates
5.7—Calculation of mixture temperature
5.8—Temperature loss during delivery
Chapter 6—Preparation before concreting, p. 7
6.1—Preparation of surfaces in contact with fresh concrete
6.2—Massive metallic embedments
6.3—Subgrade condition
Chapter 7—Protection against freezing and protection for concrete not requiring construction supports, p. 8
7.1—Protection methods
7.2—Protection period
7.3—Protection for strength gain
7.4—Temperature drop after removal of protection
7.5—Allowable temperature differential during stripping
Chapter 8—Protection for structural concrete requiring construction supports, p. 9
8.1—Introduction
8.2—Field-cured cylinders
8.3—In-place testing
8.4—Maturity testing
8.5—Attainment of design strength
8.6—Increasing early strength
8.7—Cooling of concrete
8.8—Estimating strength development
8.9—Removal of forms and supports
8.10—Specification recommendations
8.11—Estimating strength development—modeling of cold weather placements
Chapter 9—Equipment, materials, and methods of temperature protection, p. 14
9.1—Introduction
9.2—Insulating materials
9.3—Selection of insulation when supplementary heat is not used
9.4—Selection of insulation for use with hydronic heaters
9.5—Heaters
9.6—Enclosures
9.7—Internal heating
9.8—Temperature monitoring
9.9—Temporary removal of protection
9.10—Insulated forms
Chapter 10—Curing requirements and methods, p. 21
10.1—Introduction
10.2—Curing during the protection period
10.3—Curing following the protection period
Chapter 11—Acceleration of setting and strength development, p. 21
11.1—Introduction
11.2—Accelerating admixtures
11.3—Rapid-setting cements
Chapter 12—References, p. 24
12.1—Referenced standards and reports
12.2—Cited references
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This European Standard specifies performance requirements as defined in Table 1 and describes test methods for precast concrete pipes and fittings, unreinforced, steel fibre and reinforced, with flexible joints (with seals either integrated in the units or supplied separately) and nominal sizes not exceeding DN 1 750 for units with a circular bore or WN/HN 1 200/1 800 for units with an egg-shaped bore, for which the main intended use is the conveyance of sewage, rainwater and surface water under gravity or occasionally at low head of pressure, in pipelines that are
generally buried.
Provision is made for the evaluation of conformity of units to this European Standard.
Marking conditions are included.
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Features
Focuses on applied rather than fundamental materials science
Covers numerous types of materials and areas of application
Includes up-to-date references in each chapter
Requires only a nominal background in fundamental material science
Summary
Materials are the foundation of technology. As such, most universities provide engineering undergraduates with the fundamental concepts of materials science, including crystal structures, imperfections, phase diagrams, materials processing, and materials properties. Few, however, offer the practical, applications-oriented background that their students need to succeed in industry.
Applied Materials Science: Applications of Engineering Materials in Structural, Electronics, Thermal, and Other Industries fills that gap. From a cross-disciplinary perspective that reflects both the multifunctionality of many materials and the wide scope industrial needs, the author examines the practical applications of metal, ceramic, polymer, cement, carbon, and composite materials across a broad range of industries. The topics addressed include electronic packaging, smart materials, thermal management, nondestructive evaluation, and materials development. The text is clear, coherent, and tutorial in style, includes numerous up-to-date references, and provides background material in a series of appendices.
Unique in its breadth of coverage of both materials and their applications, Applied Materials Science is both scientifically rich and technologically relevant. If you work or teach those that aspire to work in an engineering capacity, you will find no text or reference that better prepares its readers for real-world applications of engineering materials.
INTRODUCTION TO MATERIALS APPLICATIONS
MATERIALS FOR THERMAL CONDUCTION
POLYMER-MATRIX COMPOSITES FOR MICROELECTRONICS
MATERIALS FOR ELECTROMAGNETIC INTERFERENCE SHIELDING
CEMENT-BASED ELECTRONICS
SELF-SENSING OF CARBON FIBER POLYMER-MATRIX STRUCTURAL COMPOSITES
STRUCTURAL HEALTH MONITORING BY ELECTRICAL RESISTANCE MEASUREMENT
MODIFICATION OF THE SURFACE OF CARBON FIBERS FOR USE AS A REINFORCEMENT IN COMPOSITE MATERIALS
APPLICATIONS OF SUBMICRON DIAMETER CARBON FILAMENTS
IMPROVING CEMENT-BASED MATERIALS BY USING SILICA FUME
Appendices
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EN 15037-1:2008
Precast concrete products - Beam-and-block floor systems - Part 1: Beams
This European Standard deals with the requirements, the basic performance criteria and evaluation of conformity for precast beams made of reinforced or prestressed normal or lightweight concrete according to EN 1992-1-1:2004, with or without clay shell, used in conjunction with blocks in compliance with prEN 15037-2 or prEN 15037-3 or prEN 15037-4 or prEN 15037-5, with or without cast in-situ concrete for the construction of beam-and-block floor and roof systems. Examples of typology of floor and roof systems are given in Annex B.
It is essential that the total depth of the beam be comprised between 60 mm and 300 mm and the beams be at centres of not more than 1,00 m.
For higher depth, it is essential that the precast concrete beams be in compliance with EN 13225.
The products covered by this standard are intended to be used as structural floor and roof systems, including parking areas for light vehicles corresponding to traffic category F of EN 1991-1-1:2002, which are not subjected to fatigue loading.
The products may be used in seismic areas provided they fulfil the requirements specific to this use.
EN 15037-2:2009
Precast concrete products - Beam-and-block floor systems - Part 2: Concrete blocks
This European Standard deals with the requirements and the basic performance criteria for blocks made in normal or lightweight aggregate concrete, used in conjunction with precast concrete beams in compliance with EN 15037-1, with or without cast-in-situ concrete for the construction of beam-and-block floor and roof systems.
Examples of typology of floor and roof systems are given in Annex B of EN 15037-1:2007.
EN 15037-3:2009
Precast concrete products - Beam-and-block floor systems - Part 3: Clay blocks
This European Standard deals with the requirements and the basic performance criteria for blocks made in clay, used in conjunction with precast concrete beams in compliance with EN 15037-1, with or without cast-in-situ concrete for the construction of beam-and-block floor and roof systems.
Examples of typology of floor and roof systems are given in Annex B of EN 15037-1:2008.
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Posted by: tynhanh - 12-14-2010, 12:48 AM - Forum: Archive
- No Replies
DeGroot, D.J. and T.C. Sheahan (1995). “Laboratory Methods for Determining Engineering Properties of Overconsolidated Clays,” Transportation Research Board, Transportation Research Record No. 1479, Engineering Properties and Practice in Overconsolidated Clays, pp. 17-25.
Posted by: plngage - 12-14-2010, 12:38 AM - Forum: Archive
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Hi all...
Now I have design expressway in Can tho city of vietnam so should be used
main technical specification for expressway TCVN 5729-2007 and Highway − Specifications for design TCVN 4054 : 2005 but we cant study in vietnam language, please suggest me.
Posted by: yly8 - 12-14-2010, 12:33 AM - Forum: Archive
- No Replies
hi to every one
does any one has this papers: Banchik, C.A., "Effective Beam Width Coefficients for Equivalent Frame Analysis of Flat-Plate Structures", ME thesis, University of California at Berkeley, Calif., May 1987, 56pp
Guide for Curing of Portland Cement Concrete Pavements, Volume I
Author: Toy S. Poole | Size: 0.63 MB | Format:PDF | Publisher: Federal Highway Administration | Year: 2005 | pages: 52
This document provides guidance on details of concrete curing practice as they pertain to
construction of portland cement concrete pavements. The guide is organized around the major
events in curing pavements: curing immediately after placement (initial curing), curing during
the period after final finishing (final curing), and termination of curing and evaluation of
effectiveness of curing. Information is presented on selection of curing materials and
procedures, analysis of concrete properties and jobsite conditions, and on ways to adjust
curing practice to account for specific project conditions.
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