30 Haziran 2009 Salı

Useful links

www.cdrecycling.org CMRA – Construction Materials Recycling Association: The first association devoted exclusively to the needs of the rapidly expanding North American construction waste & demolition debris processing and recycling industry.

www.usgbc.org The U.S. Green Building Council is the nation’s foremost coalition of leaders from across the building industry working to promote buildings that are environmentally responsible, profitable and healthy places to live and work.

www.usgbc.org/LEED The LEED (Leadership in Energy and Environmental Design) Green Building Rating System is a voluntary national standard in which construction and renovation projects earn credits toward certification as sustainable buildings. USGBC’s members developed and continue to refine LEED.

www.ecco.org Members of the Environmental Council of Concrete Organizations are dedicated to improving the quality of the environment by working to increase awareness of the environmental aspects and benefits of concrete and concrete products. The ECCO Reference Library contains nearly 2000 bibliographic references and abstracts on the environmental impacts of concrete and concrete construction.

Download: ECCO’s info sheet: Recycling Concrete & Masonry

www.pavement.com ACPA – The American Concrete Pavement Association represents concrete pavement contractors, cement companies, equipment and material manufacturers and suppliers. Their mission is to make portland cement concrete the material of choice for airport, highway, industrial, street and local road pavements.

www.cement.org Founded in 1916, the Portland Cement Association represents cement companies in the United States and Canada. It conducts market development, engineering, research, education, and public affairs programs.

Download: An Engineer’s Guide to Building Green With Concrete

Download: PCA Recycled Concrete A Bibliography of Resources

www.cement.org/tech/cct_aggregates_recycled.asp The Portland Cement Association (PCA) Concrete Technology: Recycled Aggregates page.

www.iprf.org/ The Innovative Pavement Research Foundation (IPRF) is a 501(c) (3) corporation, jointly sponsored by the American Concrete Pavement Association and Portland Cement Association.

www.beyondroads.com Sponsored by the Asphalt Education Partnership (AEP), a resource for information on the asphalt industry, its operations, its products and issues.

www.arra.org The Asphalt Recycling & Reclaiming Association is an international non-profit trade association of contractors, equipment manufacturers, suppliers, public officials, and engineers engaged in the recycling and reclaiming of asphalt.

www.crbt.org The Center for Resourceful Building Technology (CRBT) is a project of the National Center for Appropriate Technology (NCAT). CRBT promotes environmentally responsible practices in construction.

www.nssga.org NSSGA is the National Stone, Sand and Gravel Association. On Feb. 12, 2001, the merged National Stone Association and National Aggregates Association became the NSSGA. The association represents the crushed stone, sand and gravel-or aggregates-industries.

link The American Road & Transportation Builders Association (ARTBA) is the U.S. transportation construction industry's representative in Washington, D.C. Its mission: advocating strong federal investment in the nation's transportation infrastructure to meet public demand for a safe and efficient business transportation network.

www.agc.org The Associated General Contractors of America (AGC) is the nation's largest and oldest construction trade association, established in 1918 after a request by President Woodrow Wilson. Wilson recognized the construction industry's national importance and desired a partner with which the government could discuss and plan for the advancement of the nation. AGC has been fulfilling that mission for the last 85 years.

http://www.concrete.org Founded in 1904, the American Concrete Institute (ACI) has produced more than 400 technical documents, reports, guides, specifications, and codes for the best use of concrete; conducts about 125 educational seminars each year; and has 13 different certification programs for concrete practitioners, as well as a scholarship program to promote careers in the industry.

www.acaa-usa.org The American Coal Ash Association (ACCA) is a not-for-profit organization that promotes the beneficial use of coal combustion products (CCPs).

www.afandpa.org Trade association for wood, paper and wood products.

www.nrmca.org The National Ready Mixed Concrete Association supports continued expansion and improvement of the ready mixed concrete industry through leadership, advocacy, professional development, promotion and partnering.

www.ascconline.org The American Society of Concrete Contractors was formed by and for concrete contractors and others who provide services and goods to the industry.

www.abc.org The Associated Builders and Contractors (ABC) association represents 23,000 merit shop construction and construction-related firms in 79 chapters across the United States.

www.concretesdc.org The Strategic Development Council (SDC) brings together the concrete industry, along with government, academia, and customers, to focus on collaborative problem-solving in meaningful technology advancement.

Government Agencies
www.epa.nsw.gov.au/waste/wg-80.htm Community Waste Reduction Grants

www.fhwa.dot.gov/pavement/pavecont.cfm#sha U.S. DOT Federal Highway Administration (FHWA) List of Pavement Contacts

www.tfhrc.gov/hnr20/recycle/wrc.htm#contact FHWA Recycling Team

www.fhwa.dot.gov/pavement/recycling/rcaca.efm Summary of California Recycled Concrete Aggregate Review

www.fhwa.dot.gov/construction FHWA Construction & Maintenance

www.fhwa.dot.gov/pavement FHWA Pavement Technology

www.fhwa.dot.gov/pavement/recycling/rca.cfm FHWA Recycled Concrete Aggregate National Review

www.fhwa.dot.gov/preservation FHWA Transportation System Preservation

www.dot.ca.gov/hq/esc/oe/specifications/std_specs/2006_StdSpecs/2006_StdSpecs.pdf Caltran’s Specifications for Aggregate Subbase and Base

Educational Institutions
www.rmrc.unh.edu/ The Recycled Materials Resource Center (RMRC) is a national center created to promote the wise use of recycled materials (pavements, secondary, waste, byproduct materials) in the highway environment. The Center is a partnership with the Federal Highway Administration (FHWA).

construction.asu.edu The Del E. Webb School of Construction at Arizona State University (ASU) studies technologies for implementation in the construction industry and promotes international relationships.

www.engr.utexas.edu/icar/index.cfm The International Center for Aggregates Research (ICAR) is a joint operation of The University of Texas at Austin and Texas A&M University. ICAR’s goal is finding the most efficient and effective use of the aggregates industry’s resources through research, education, and information exchange.

www.eng.auburn.edu/research/centers/ncat.html The National Center for Asphalt Technology (NCAT) at Auburn University NCAT’s mission: Improve HMA performance through research, education, and information services.

www.wcct.net The World Center for Concrete Technology (WCCT) offers training, educational research and conferences for the concrete products industries.

www.mtaci.com The Middle Tennessee American Concrete Institute (MTACI), also known as the Concrete Club, works to develop business relationships within the industry, develop knowledge of concrete practices, and to promote the Concrete Industry Management program.

Other Organizations
www.acce-hq.org The American Council for Construction Education (ACCE) accredits construction education programs in colleges and universities that request its evaluation and meet its standards and criteria.

www.transportation.org The American Association of State Highway and Transportation Officials advocates transportation-related policies and provides technical services to support states in their efforts to efficiently and safely move people and goods.

www.irfnet.org Since 1948, the International Road Federation (IRF) has been active in the advocacy of all issues relevant to the road industry, from financing to technology and from development to safety.

www.greenerbuildings.com Greener Buildings provides an overview of the world of greener buildings, including the latest findings on the bottom-line payoffs.

www.Fp2.org The Foundation for Pavement Preservation (FP2) is a non-profit organization supported by the pavement preservation industry; contractors, material suppliers, equipment manufacturers, consulting engineers, and academia.

www.recyclingmarkets.net RecyclingMarkets.net provides access to North America's Most Comprehensive searchable database of more than 17,000 companies involved in the Recycling Process throughout the USA and Canada.

www.hormigonfihp.org/indexen.html The Iberoamerican Federation of Ready Mixed Concrete (FIHP) is a non-profit organization, that gathers the national associations and companies from the Ibero-american countries which may use the ready mixed concrete.

www.ecoba.com ECOBA represents its members in different regulatory bodies and work together with European Commission directorates, European Union standardization committees, International Treaty Organizations, National standardization committees, and research institutes.

www.aggregain.org.uk AggRegain is a free sustainable aggregates information service provided by the WRAP Aggregates Programme.

www.epa.nsw.gov.au/waste/wg-80.htm Australian EPA development of chemical contaminants guidelines for recycled concrete aggregates (RCA) in new construction.

Research
www.onderzoekinformatie.nl/en/oi/nod/onderzoek/ONK1296656/ Subproject: The sustainable management and use of recycled aggregates

www.b-i-m.de/public/TUdmassiv/dacon98baratta.htm Within the scope of this study, different concrete mixtures were manufactured to determine the influence of aggregate derived from recycled mineral building material referring to stress-strain relation of concrete.

www.b-i-m.de/public/tudmassiv/damcon99ruehl.htm The influence of recycled aggregate on the stress-strain relation of concrete.

www.dundee.ac.uk/civileng/research/concrete/pii/RCA.htm Demonstration Project Utilizing Coarse Recycled Aggregates Concrete Technology Unit: University of Dundee.

www.rip.trb.org The Transportation Research Board’s (TRB) Research in Progress (RiP) website contains the RiP database which contains over 7,800 transportation research projects. The RiP database allows users in State DOT to add, modify and delete information on their current research projects.

www.strath.ac.uk/Departments/Civeng/staff/cairns/research.htm The Department of Civil Engineering at the University of Strathclyde in Glasgow. The use of demolished concrete as aggregate in the production of fresh concrete was investigated together with partners at La Sapienza in Rome and the Italian contractors Mabbo Appunto and Pescara.

www.csiro.au/promos/ozadvances/Series8Concrete.html Australia Advances Series Eight on recycled concrete. Kwesi Sagoe-Crentsi CSIRO Manufacturing and Infrastructure Technology.

www.odpm.gov.uk/index.asp?id=1143386 Research study "Aggregates Advisory Service" commissioned by the Office of the Deputy Prime Minister.

www.odpm.gov.uk/index.asp?id=1143386 NOD – Dutch Research Database Subproject: The sustainable management and use of recycled aggregates.

www.dundee.ac.uk/civileng/research/concrete/pii/RCA.htm University of Dundee Concrete Technology Unit – Demonstration project using coarse recycled aggregates.

Literature List
If you have any suggestions to add to these resources please contact the CMRA at 630-585-7530 or info@cdrecycling.org.

Books and Manuals
Liu, Tony and Meyer, Christian
Recycling Concrete and Other Materials for Sustainable Development
American Concrete Institute, 2004.

RILEM Publications
International RILEM Conference on the Use of Recycled Materials in Buildings and Structures
Bagneux, France, 2004.

Kosmatka, S.H., Kerkhoff, B., and Panarese, W.C.
Design and Control of Concrete Mixtures
14th Edition, 2002.

The Basic Asphalt Recycling Manual (BARM)
Available at: http://www.arra.org/publications.html

Portland Cement Association (PCA)
Download: PCA Recycled Concrete a Bibliography of Resources

Reports and Journals
Alan D. Buck, “Recycled Concrete as a Source of Aggregate”, ACI Journal, American Concrete Institute, Detroit, May 1977.

A.A. Di Maio, C.J. Zega, and L. P. Traversa, “Estimation of Compressive Strength of Recycled Concrete with the Ultrasonic Method”, Journal of ASTM International, Vol. 2, No. 5, May 2005.

Fergus, J.S. “The Effect of Mix Design on the Design of Pavement Structures When Utilizing Recycled Portland Cement Concrete as Aggregate”, Ph.D. Thesis, Department of Civil Engineering, Michigan State University, l980.

FHWA, “Recycled Concrete: A Valuable Transportation Resource”, 2005, www.thfrec.gov/focus/apr05/03.htm

FHWA, “Recycled Concrete Aggregate”, FHWA National Review, 2004, www.fhwa.dot.gov/pavement/recycling/rca.cfm

Forster, S. W. “Recycled Concrete as Aggregate”, Concrete International, American Concrete Institute, Michigan, October l986.

Hansen, T.C., and Boegh, E., “Elasticity and Drying Shrinkage of Recycled-Aggregate Concrete”, ACI Journal, Volume 82. No. 5, September-October, 1985.

T.C. Hansen, “Mechanical Properties of Recycled Aggregate Concrete” RILEM Report, Recycling Demolished Concrete and Masonry, 1992.

T.C. Hansen, Recycling of Demolished Concrete and Masonry
RILEM Report 6, E & FN Spon, London, 1992.

Information on Recycled Concrete Aggregate from the Recycled Materials Resource Center, University of New Hampshire- http://www.rmrc.unh.edu

B. Juric, L. Hanzic, R. Ilic, N. Samec, “Utilization of Municipal Solid Waste Bottom Ash and Recycled Aggregate in Concrete,” Waste Management (2005)1-7.

Katz, A., “Treatments for the Improvement of Recycled Aggregate” American Society of Civil Engineers, Vol. 16, No. 6, November/December, 2004.

Kikuchi, M., and Mukai, T., “A Study on the Properties of Recycled Aggregate and Recycled Aggregate Concrete,” Canadian Aeronautics and Space Journal, No. 31, l983.

Lee, S., Moon, H., Swamy, R., Kim, S. and Kim, J., “Sulfate Attack of Mortars Containing Recycled Fine Aggregates”, ACI Materials Journal, Vol. 102, No. 4, July-August, 2005.

Salomon M. Levy, Paulo Helene, “Durability of Recycled Aggregates Concrete: A Safe Way to Sustainable Development” Cement and Concrete Research 34 (2004) 1975-1980.

Li, X., Gress, D., “Mitigating alkali silica reaction in concrete containing recycled concrete aggregate”, Transportation Research Record, Vol. 1979, pp. 30-35, 2006.

Meininger, Rick, Personal Communications, August 2005.

Mukai, T., Kemi, T., Nakagawa, M. and Kikuchi, M. “Study of Reuse of Waste Concrete for Aggregate of Concrete,” Proceeding of the Seminar on Energy and Resources Conservation in Concrete Technology, Japan-US Cooperative Science Program, San Francisco, CA, 1979.

F.T. Olorunsogo, N. Padayachee, “Performance of Recycled Aggregate Concrete Monitored by Durability Indexes” Cement and Concrete Research 32 (2002) 179-185.

Otsuki, N., Miyazato, S., and Yodsudjai, W., “Influence of Recycled Aggregate on Interfacial Transition Zone, Strength, Chloride Penetration and Carbonation of Concrete”, Journal of Materials in Civil Engineering, Vol. 15, No. 5, pp. 443-451, September-October, 2003.

C. Park, J. Sim, “Fundamental Properties of Concrete Using Recycled Concrete Aggregate Produced Through Advanced Recycling Progress,” TRB 2006, 13p, #06-0810.

Khaldoun Rahal, “Mechanical Properties of Concrete with Recycled Coarse Aggregate” Building Environment (2005) 1-8

K. Ramamurthy, K.S. Gumaste, “Properties of Recycled Aggregate Concrete”, Indian Concrete Journal, 72:11, 49-53, 1998.

Rasheeduzzafar, A. K., and A. Khan, “Recycled Concrete- A Source of New Aggregate,” Journal of the American Society of Testing Materials, Cement, Concrete and Aggregate, Vol. 6, No. 1, 1984.

The Ready Mixed Concrete Industry LEED Reference Guide, 2006, RMC Research and Education Foundation, http://www.rmc-foundation.org/newsite/index.htm

Recycled Concrete Aggregate, Concrete, vol.5, no. 5, May 2005, p.27-29. http://www.concrete.org.uk

"Recycling Concrete Pavement," Concrete Paving Technology, TB-014P
American Concrete Pavement Association, Skokie, Illinois, 1993.

Recycling Portland Cement Concrete, DP-47-85
Demonstration Project Program, Federal Highway Administration, Washington, D.C., 1985.

Removal and Reuse of Hardened Concrete, ACI Committee 555R-04 Report, American Concrete Institute, Michigan, 2004.

D. Sani, G. Moriconji, G. Fava, V. Corinaldesi, “Leachingand Mechanical Behavior of Concrete Manufactured with Recycled Aggregates” Waste Management 25 (2005) 177-182.

Scott, H.C., and Gress, D.L. “Mitigating ASR in Recycled Concrete”, ACI SP-219-5, American Concrete Institute, Vol. 219, March 1, 2004.

Shayan, A. and Xu, A. “Performance and Properties of Structural Concrete Made with Recycled Concrete Aggregate”, ACI Materials Journal, Vol. 100, No. 5, September-October, 2003.

Snyder, M., “Physical and Mechanical Properties of Recycled PCC Aggregate Concrete” Interim Report-Task A, DTFH61-93C-00133, U.S. Department of Transportation, Federal Highway Administration, June 1994.

Sri Ravindrarajah, R., and C.T. Tam, “Properties of Concrete Made with Crushed Concrete as Coarse Aggregate,” Magazine of Concrete Research, Volume 37, No. 130, Cement and Concrete Association, March 1985.

Sri Ravindrarajah, R., and C.T. Tam, “Recycling Concrete as Fine Aggregate in Concrete” International Journal of Cement Composites and Lightweight Concrete, Volume 9, No. 4, November 1987.

Standard Specification for Reclaimed Concrete Aggregate for Use as Coarse Aggregate in Portland Cement Concrete, http://www.rmrc.unh.edu/Research/Rprojects/Project13/Specs/docs/finalspecRCA-PCC.pdf.

David Stark, The Use of Recycled-Concrete Aggregate from Concrete Exhibiting-Silica Reactivity, Research and Development Bulletin RD114,
Portland Cement Association, Skokie, Illinois, 1996.

Stark, D., “The Use of Recycled –Concrete Aggregate from Concrete Exhibiting Alkali-Silica Reactivity”, PCA Research and Development Bulletin RD114, Skokie, Illinois, Portland Cement Association 1996.

Vivian Tam, X.F. Gao, C.M. Tam, “Microstructural Analysis of Recycled Aggregate Concrete Produced from Two-Stage Mixing Approach” Cement and Concrete Research 35 (2005) 1995-1203.

Mostafa Tavakoli, Parviz Soroushian, “Drying Shrinkage Behavior of Recycled Aggregate Concrete,” Concrete International, p. 58-61 Nov. 1996

Tavakoli, M., Soroushian, P., “Strengths of Recycled Aggregate Concrete made using Field-demolished Concrete as Aggregate”, ACI Materials Journal. Vol. 93, No. 2, pp. 182-190. l996.

Technical Advisory, “Use of Recycled Concrete Pavement for Aggregate in Hydraulic Cement Concrete Pavement,” T 5040.37, July, 2007 http://www.fhwa.dot.gov/legsregs/directives/techadvs/t504037.htm.

Transportation Applications of Recycled Concrete Aggregate, FHWA State of the Practice National Review, Sept. 2004, http://www.rmrc.unh.edu/Resources/PandD/RCA/Report/RCAREPORT.pdf

William Turley, "What Does it Cost to Recycle Concrete & Asphalt"
C&D Debris Recycling, Chicago, April 1994.

Use of Recycled Materials – Final Report of RILEM TC 198-URM, edited by Ch. F. Hendriks, G.M.T. Janssen and E. Vazquez, pp. 41-43, http://www.rilem.net/repDetails.php?rep=rep030.

WSDOT 2002 Standard Specifications – Recycled Concrete Aggregate www.metrokc.gov/procure/green/concrete.htm#8

M. C. Won, Use of Crushed Concrete as Aggregate for Pavement Concrete,
Research Section, Construction Division, Texas Department of Transportation, Austin, Texas, 1999.

Jianzhurang Xiao, Jiabin Li, Ch. Zhang, “Mechanical Properties of Recycled Aggregate Concrete Under Uniaxial Loading, “Cement and Concrete Research 35(2005) 1187-1194.

Yrjanson, W. A., Recycling of Portland Cement Concrete Pavements, NCHRP Synthesis 154, National Cooperative Highway Research Program, Transportation Research Board, Washington, DC, 1989.

Tsung-Yeuh Tu, Yuen-Yuen Chen, Chao-Lung Hwang, “Properties of HPC with Recycled Aggregates”, Cement and Concrete Research, Vol. 36, No 5, pp. 943-950, May 2006.

Roumiana Zaharieva, Francois Buyle-Bodin, Eric Wirquin, “Frost Resistance of Recycled Aggregate Concrete” Cement and Concrete Research 34 (2004) 1928-1932.

http://www.tfhrc.gov/pubrds/fall94/p94au32.htm
FHWA Report "The Use of Recycled Materials in Highway Construction"
Download: FHWA Transportation Applications of Recycled Concrete Aggregate

User Guidelines for Waste and Byproduct Materials in Pavement Construction
FHWA-RD-97-148
FHWA Contact: Marcia Simon (202) 493-3071

Pavement Recycling Guidelines for State and Local Governments
FHWA-SA-98-042
FHWA Contact: Mr. Kevin Connor (202) 493-3187

Transportation Applications of Recycled Concrete Aggregate
FHWA-IF-05-013
FHWA Contact: Mr. Jason Harrington 202-366-1576

ICAR Publications (International Center for Aggregate Recycling) www.engr.utexas.edu/icar/publications/index.cfm
Research Report ICAR 101-1
An Investigation of the Status of By-Product Fines in the United States
The handling and disposal of fines produced as a result of the aggregate crushing and production process are some of the major problems facing the aggregate industry today, having both economic and environmental implications. This report describes a major effort undertaken to quantify and characterize these fines, their location, character, and sales.

Research Report ICAR 101-2F
Framework for Development of a Classification Procedure for Use of Aggregate Fines in Concrete
The focus of this project was to examine the methods and test procedures used in the past to characterize the properties of fines, and develop, on a preliminary basis, a framework to characterize and catalogue the properties of aggregate fines, propose new ones that would eventually complement a set of guidelines for the use of aggregate fines in portland cement concrete. Possible applications of aggregate fines, such as in high-performance concrete, controlled low strength materials, and insulated concrete forms are discussed as future directions of research.

Research Report ICAR 102-1F
An Experimental Study on the Guidelines for Using Higher Contents of Aggregate Microfines in Portland Cement Concrete
This report presents some of the effects of high fines on the properties of cement mortar and concrete.

ICAR 103: Use of High Fines Concrete (HFC) in Insulated Concrete Form (ICF) Construction
This project work consisted of developing technical data to justify, from the standpoint of material properties (of aggregate fines and HFC), construction efficiency, cost competitiveness, and energy performance, a basis for the use of high-fines concrete (HFC) inside ICF wall systems.

ICAR 104: Guidelines for Proportioning Optimized Concrete Mixtures with High Microfines
The optimization of aggregates is advantageous for economical and technical reasons; however, the availability of materials and construction operations can dictate the proportions of fine and coarse aggregates. Some general guidelines based on field experience, other investigations and the results of this investigation are presented.

ICAR 104-1F: The Effects of Aggregates Characteristics on the Performance of Portland Cement Concrete
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.

ICAR 105-1: Summary of Concrete Workability Test Methods
This project describes 61 test methods for measuring concrete workability.

ICAR 105-2: Qualification of Concrete Workability by Means of the Vibrating Slope Apparatus
A new device, the Vibrating Slope Apparatus (VSA), developed for qualifying concrete workability under vibration, was borrowed by the International Center for Aggregates Research (ICAR) Project 105 researchers for evaluation.

ICAR 105-3F: Development of a Portable Rheometer for Fresh Portland Cement Concrete
The purpose of this research was to identify an effective field test method for measuring the workability of concrete in general and of high-microfines concrete in particular.

ICAR 201 Series: Superpave Aggregate Specifications
A comprehensive research program was conducted in three concurrent phases which examined the Superpave fine aggregate angularity (FAA) test, the restricted zone requirement, and the voids in the mineral (VMA) specification.

In this 201 series you will find the following reports:

201-1, “Evaluation of Superpave Fine Aggregate Angularity Specification,” Arif Chowdhury, Joe Button, Vipin Kohle and David Jahn.

201-2, “Effects of Superpave Restricted Zone on Permanent Deformation,” Arif Chowdhury, Joe Button, and Jose Grau.

201-3F, “Effects of Aggregate Gradation and Angularity on VMA and Rutting Resistance,” Dae-Wook Park, Arif Chowdhury, and Joe Button.

Research Report ICAR 203-1
Evaluation of Aggregate Characteristics Affecting HMA Concrete Performance

This report documents the outcomes of the ICAR study on the Evaluation of Aggregate Characteristics Affecting HMA Concrete Performance. This study was conducted with support from the Federal Highway Administration (FHWA) program on Simulation, Imaging, and Mechanics of Asphalt Pavements at Texas A&M University.

Research Report ICAR 301-1F
Alkali-Silica Reaction in Portland Cement Concrete: Testing Methods and Mitigation Alternatives, (pp 548)

Identifying the susceptibility of an aggregate to alkali-silica reaction (ASR) before using it in concrete is one of the most efficient practices for preventing damage and failure.

ICAR 501 Series: Increased Single-Lift Thicknesses for Aggregate Base Courses
This project was initiated specifically to investigate the potential for placing unbound aggregate base courses in thicker lifts to improve pavement performance, reduce costs, and increase the amount of aggregates used.

In this 501 series you will find the following reports:

501-2, “A Study on the Feasibility of Compacting Unbound Graded Aggregate Base Courses in Thicker Lifts than Presently Allowed by State Departments of Transportation,” Jaime L. Bueno, Kenneth H. Stokoe, II, and John J. Allen

501-3, “Prediction of Working Load Displacements Under Plate Loading Tests from Seismic Stiffness Measurements,” Michael L. Myers, Kenneth H. Stokoe, II, and John J. Allen

501-5F, “Increased Single-Lift Thicknesses for Unbound Aggregate Base Courses,” John J. Allen , Jaime L. Bueno, Michael E. Kalinski, Michael L. Myers, and Kenneth H. Stokoe, II

Reports 501-1 and 501- 4 were internal documentation only and were not published.

ICAR 502 Series: Structural Considerations of Unbound Aggregate Layers for Mechanistic Design
AASHTO is moving towards a mechanistic pavement design procedure for the Design Guide- 2002. This guide will establish the structural contribution of various materials used as pavement layers.

In this 502 series are the following reports:

502-1, “Structural Characteristics of Unbound Aggregate Bases to meet AASHTO 2002 Design Requirements: Interim Report,” Alex Adu-Osei, Dallas Little and Robert Lytton

502-2, “Field Validation of the cross-Anisotropic Behavior of Unbound Aggregate Bases,” Erol Tutumluer, Alex Adu-Osi, Dallas Little and Robert Lytton

502-3, “Characterization of Unbound Granular Layers in Flexible Pavements,” Alex Adu-Osei

ICAR 503 Series: Rapid Test to Establish Grading of Unbound Aggregates
The objective was to develop a test method that can operate in an automatic, continuous sampling mode.

In this 503 series are the following reports:

503-1, “Evaluation of Potential Aggregate Grading Technologies,” Alan F. Rauch, Carl T. Hass, Hyoungkwan Kim, and Craig Browne

503-2, “An Evaluation of Automated Devices to Replace and Augment Manual Sieve Analyses in Determining Aggregate Gradation,” Alan F. Rauch, Carl T. Haas, Craig Browne, and Hyoungkwan Kim

503-3F, “Automation of Aggregate Characterization Using Laser Profiling and Digital Image Analysis,” Carl T. Haas, Alan F. Rauch, Hyoungkwan Kim, and Craig Browne

Magazines
Construction and Demolition Recycling Magazine
www.cdrecycler.com

Public Roads Magazine
www.tfhrc.gov/pubrds/pubrds.htm

Recycling Today Magazine
www.recyclingtoday.com

Rock Products eNewsletter
http://rockproducts.com/mag/rock_studies_refine_aggregate/

What are the major markets for recycled concrete?

Markets for recycled concrete are ever expanding. To date, recycled concrete aggregate has been use in/as aggregate base course (road base), ready mix concrete, asphalt pavement, soil stabilization, pipe bedding and landscape materials.
How is recycled concrete processed?
Products aside from base course are high quality aggregate, processed in steps with time and effort involved in crushing, pre-sizing, sorting, screening and contaminant elimination. Denominator is to start with a clean, quality, rubble in order to meet design criteria much more easily.
Are there any regulatory concerns regarding recycling or use of recycled concrete?
Regulatory issues vary from state to state and agency to agency. In 2005, California wrote legislation mandating and accepting the use of recycled into new concrete. Generally, American Society for Testing and Materials (ASTM) and American Association of State Highway and Transportation Officials (AASHTO) are national trendsetters on issues accepted by agencies across the U.S. Their specifications allowing for recycled aggregate use reinforces confidence in recycled products.
Is concrete recycling regulated?
Concrete recycling can be regulated by state environmental authorities. For example, in New Jersey all concrete recyclers have to obtain a Class B license in order to crush.

Is it feasible to recycle concrete?

The recycling and re-use of concrete aggregate makes sense. Here are the value engineering benefits:

Produce specification sized recycled aggregates at your location
Minimize impact to community infrastructure by reducing import and export trucking
Avoid haul-off costs and landfill disposal fees
Eliminate the expense of aggregate material imports and exports
Increase project efficiency and improve job cost - recycled concrete aggregates yield more volume by weight (up to 15%)

How Concrete is Recycled

Products (aside from base course) are high quality aggregate, processed in steps with time and effort involved in crushing, pre-sizing, sorting, screening and contaminant elimination. The denominator is to start with clean, quality rubble in order to meet design criteria easily and ultimately yield a quality product that will go into end use.

Crushing and screening systems start with primary jaws, cones and/or large impactors taking rubble from 30 inches to 4 feet. A secondary cone or impactor may or may not need to be run, and then primary and secondary screens may or may not be used, depending upon the project, the equipment used and the final product desired. A scalping screen will remove dirt and foreign particles. A fine harp deck screen will remove fine material from coarse aggregate.

Further cleaning is necessary to ensure the recycled concrete product is free of dirt, clay, wood, plastic and organic materials. This is done by water floatation, hand picking, air separators, and electromagnetic separators.

Occasionally asphalt overlay or patch is found. A mixture of asphalt and concrete is not recommended but small patches are not detrimental.

The more care that is put into the quality, the better product you will receive. With sound quality control and screening you can produce material without having to wash it as with virgin aggregate which may be ladened with clay and silt.

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Recycled concrete aggregate:

Is high quality - meeting or exceeding all applicable state and federal specifications
Is an accepted source of aggregate into new concrete by ASTM and AASHTO.
Is currently being used in concrete and asphalt products with better performance over comparable virgin aggregates.
Provides for superior compaction and constructability.
Is higher yield - recycled aggregates are lighter weight per unit of volume, which means less weight per cubic yard, resulting in reduced material costs, haul costs, and overall project costs.
Weighs ten to fifteen percent (10%-15%) less than comparable virgin quarry products (concrete).
Offers a way to reduce landfill waste streams.
Means minimization of environmental impacts in an Urban Quarry setting.

Concrete recycling

Concrete recycling is becoming an increasingly popular way to utilize aggregate left behind when structures or roadways are demolished. In the past, this rubble was disposed of in landfills, but with more attention being paid to environmental concerns, concrete recycling allows reuse of the rubble while also keeping construction costs down.

Created by the Construction Materials Recycling Association (CMRA) web site provides all of the available information about concrete recycling. Information contained here will assist recyclers in increasing their markets and will answer questions regulators and purchasing agents for end markets, such as state DOT officials, might have about the recycled concrete aggregate product.

Some Beneficial Reuse Options

Non-hazardous and non-dangerous spent sand has
traditionally been used as "clean fill" in many parts of
Washington State. However, "clean fill" opportunities
have declined in recent years, making exploration and
implementation of other applications essential. Spent
foundry sand has been successfully used throughout the
United States in various applications. Below are some
recycling options for spent sand:
· Asphalt Concrete: Substitution of up to 15% spent
sand for conventional asphalt concrete fine aggregate.
· Compost Additive: Bulking agent for composted yard
waste, to produce topsoil or topsoil additive.
· Concrete: Substitution for regular sand in structural
grade concrete, at low percentages.
· Bricks and Pavers: Encapsulation in a proprietary,
high pressure, pozzolanic process that can encapsulate
and chemically bind various waste materials in C-grade
flyash (a fine particulate ash produced by coal-burning
electrical power plants). The ambient-temperature
process results in bricks that are cost effective and can
be shaped to meet end-user requirements
· Portland Cement: Cement kiln feed for portland
cement. A study by the American Foundrymen's
Society indicates that portland cement manufactured
with up to 13% of spent foundry sand exhibited
slightly higher compressive strengths than
conventionally produced portland cement, without any
degradation of key characteristics such as set time.
· Mineral Wool Products: Potential silica source.
Flowable Fill: Substitution for regular sand in
flowable fill, a mixture of sand, flyash, and water that
is mixed into a slurry and poured. Flowable fill is a
self-leveling and self-compacting mix that hardens and
develops strength over time, similar to concrete, and is
commonly used as backfill for trenches (sewer,
conduit, utility).

BENEFICIAL REUSE OF SPENT FOUNDRY SAND

The foundry industry generates a number of byproducts, of
which the largest volume is a “spent sand” that consists of
silica or olivine sand with residuals of phenolic resin, clay
or no-bake binders. The Clean Washington Center's
Recycling Technology Assistance Partnership is working
with the Washington State Chapter of the American
Foundrymen's Society (AFS) toward the implementation of
beneficial re-use applications for spent foundry sand. This
fact sheet describes common uses of foundry sand,
provides an overview of several beneficial reuse options,
and discusses issues for future development of a viable
market for the recycled sand.
Background
All foundries produce castings by pouring molten metal
into molds. The characteristics of the residuals vary from
foundry to foundry, and depend on the type of metal being
poured (iron, steel, aluminum, brass/bronze), the type of
casting process (sand casting, investment casting), and the
technology employed, particularly the type of furnace
(induction, electric arc, cupola) and the type of finishing
process (grinding, blast cleaning, coating).
Sand Casting
The most common type of casting process is known as
sand casting. There are two basic types of mixtures for
sand casting: "green" sand and "no-bake" sand. Green
sand uses a mixture of clay and water to achieve bond
strength, while no-bake sand uses synthetic resins. Sand
casting involves making a pattern of the component to be
cast, and packing sand around the pattern to produce a
hollow mold. Molds are typically made in two halves to
facilitate removal of the pattern, and then the molds are
assembled to form a "hollow" that matches the pattern's
shape. Cores, made of packed sand with special binders,
may be inserted into a mold, prior to assembly, to form
interior surfaces for complex shapes. Molten metal is
poured into the mold cavity and allowed to solidify and
cool. The casting is shaken out of the sand mold using
vibratory machines, mechanically cleaned of extraneous
metal by cutting or grinding, and blast cleaned to remove
casting sand and other surface contaminants.
Sand casting generates residuals from metal melting and
pouring, and molding processes. Residuals consist of
"spent sand" from molding and core-making, slags, and
wastes from cleaning rooms, dust collectors or scrubbers.
Depending upon the process, some foundry wastes,
including spent sand, slags, and dust collector/scrubber
wastes, may be hazardous.
Spent Foundry Sand
It is standard foundry practice to reuse molding and coremaking
sands. Residual sand is routinely screened and
returned to the system for reuse. As the sands are
repeatedly used, the particles eventually become too fine
for the molding process; and, combined with heat
degradation from repeated pourings, requires periodic
Key Words
Materials: Spent foundry sand.
Technologies: Fine aggregate substitution;
stabilization.
Applications: Asphalt concrete, bricks & pavers,
compost additive, concrete, flowable
fill, mineral wool products, portland
cement.
Market Goals: Establish variety of regional markets
throughout Washington State.
Abstract: Summary of beneficial re-use
options for spent foundry sand.
replacement of "spent" foundry sand with fresh sand.
This "spent sand" is typically non-hazardous, black in
color, and contains a large amount of fines (particles of
100 sieve size or less). Olivine and silica sands are most
common in Washington State foundries.

Foundry sand

Foundry sand consists primarily of clean, uniformly sized, high-quality silica sand or lake sand that is bonded to form molds for ferrous (iron and steel) and nonferrous (copper, aluminum, brass) metal castings. Although these sands are clean prior to use, after casting they may contain Ferrous (iron and steel) industries account for approximately 95 percent of foundry sand used for castings. The automotive industry and its parts suppliers are the major generators of foundry sand.
The most common casting process used in the foundry industry is the sand cast system. Virtually all sand cast molds for ferrous castings are of the green sand type. Green sand consists of high-quality silica sand, about 10 percent bentonite clay (as the binder), 2 to 5 percent water and about 5 percent sea coal (a carbonaceous mold additive to improve casting finish). The type of metal being cast determines which additives and what gradation of sand is used. The green sand used in the process constitutes upwards of 90 percent of the molding materials used.(1)

In addition to green sand molds, chemically bonded sand cast systems are also used. These systems involve the use of one or more organic binders (usually proprietary) in conjunction with catalysts and different hardening/setting procedures. Foundry sand makes up about 97 percent of this mixture. Chemically bonded systems are most often used for “cores” (used to produce cavities that are not practical to produce by normal molding operations) and for molds for nonferrous castings.

The annual generation of foundry waste (including dust and spent foundry sand) in the United States is believed to range from 9 to 13.6 million metric tons (10 to 15 million tons).(2) Typically, about 1 ton of foundry sand is required for each ton of iron or steel casting produced.

Additional information on the production and use of spent foundry sand in construction materials applications can be obtained from:


American Foundrymen's Society, Inc.
505 State Street
Des Plaines, Illinois 60016-8399

29 Haziran 2009 Pazartesi

The usage of fly ash at beton production

70'ies are the stage when demand for energy and enviromental avareness increases dramatically.
These increases caused to increase the production capacity of coal fired pp although
environmental problems caused by coal used at pp.
The usage of "flue ashs" at production phrasees especially construction, agriculture and chemical
sectors with and excellent results are increasingly going on at present has firstly applied in USA
and spreed out trought of the world in a short time,
The most economic results and serious technical benefits optained at cement and concrete sectors,.
The utilization of ash as an industrial disposal and the usage of concrete production as an
improver of the quality has started to be applied in at the and of 1990''s in Turkey,
All of the Coal fired power plaints produce ash suitable to standarts in Europe occupied by cement
factories and production of many typies of cements except portland cement strongened by flue ash
are higly increased.
Only 4 of all coal fired pp dispose ash suitable to use as addition all the others are not usable
according to standarts of asm., tse639, tse450
The ash disposed .from Seyitömer, Çatalağzı, Tunçbilek and Soma pp''ies canbe used only after
seperation.
The usage possibilty of the ashes depend on the quality, homonenity, the type of combustion and
the filtration of the coal fired at pp.,
The structure of flu ash is sferical and spongy and particual size varies between 1-200 |im. 85 % of
the flue ash'ies Chemical composition is made of SiO2, A12O3, Fc2O3, CaO ve MgO. The particules
of ash show senoferic and dermosfiic characteristic and they are decomposed by high temperature.
Flue ash contains low calcium in their minéralogie composition reacts with calciumhydroxide in.
their humid environments and shows their connective feature.,
That is to say they are "puzolanic". Flue ash contains high calcium has connevtive features by
themselves because of amorphous components in their chemical structure and so.
Specific surface of flue ash is vary from 1700 to 5000 enr/g, The size of ash produced from, pp
never changes If there isn't any change of manufacture condtion or row material's of the1 pp,
Ash accumulated, at elecro filters or seperated is appropriate for using with concrete and cement.
The dencity of flue ash avaragely is 800 kg/m3,.
The more its fine particule size the much its usage for cementing. The flue ash sized over 3500
blain can be directly sent, to mixing from mill. Since there is no need for grinding and drying flu
ash lowers the producing cost. Concretes produced with cements prepared with flue ash shows
decrease in hydrotion temeperatre, and shows considerable increase in. processing and endurance,.
Cement factories use flu-ash in poduction process increase the capacity at the same time.
It is possible to switch to use flu-ash at cocrete est.ablih.men.ts in a. short time by preparing many
prescriptions directly with pç or pkç
Advantages of the usage flu-ash in ready-made concrete,
218
56. Türkiye jeoloji Kurultayı
56ik Geological Congress of Turkey
A. Resistance of concrete increases higly to compare with portland-cement and this increase
lasts till 400 days(figure 1).
B. Prevents fittings-corrosion/donati korozyonu dute to its feature of filling the cavity
C. Prevents the splits in concrete as its lowering featute of the hydration. temeprature.
D. Cause to a conciderable increase in ready-made concrete
E.. Decrease some the water necessity of concrete.
K. Increase the insulation a little.
L. Increase the process rate of concrete
M, Couse the concrete pumps work, properly at managing and increase the lasting time of
parts exposed to corrosion.
N. Prevent the wrinkle
O. Stop the vomiting and dissociating of concrete.
The transporting, stock and adding into concrete of flu-ash is same as cement,...
It is possible to use it as cement for a specified proportion or to use it as fine materilas(agrega)..
The best result obtained for experiments carried out at laboratuvaries while they used for both as
cement and fine agregga.
ön the other sides flu-ash cab be used at/as:
a) brick production.
b) light-concrete production
c) with injection
d) stabilation of ground.
e) filling material
as increasingly .
' Althoug its usage at maximum rates in. the world flu-ash unfortunately is used quite under avarage
rates in Turkey.
The utilization of an industrial disposal and make it benefical for economy.»
Lowering the production cost by economy saving of energy during mar and cement production.
.Affirmative assistance for the "hazır beton" that directly affects the life standarts by final usage of.
Are the technical topics in. our country as an ear.htqua.ke teritory and economic difficulty.

Fly ash mix design

Mix Design
The substitution rate of fly ash for portland cement will vary depending upon the chemical composition of both the fly ash and the portland cement. The rate of substitution typically specified is a minimum of 1 to 1 ½ pounds of fly ash to 1 pound of cement. It should be noted that the amount of fine aggregate will have to be reduced to accommodate the additional volume of fly ash. This is due to fly ash being lighter than the cement.

The amount of substitution is also dependent on the chemical composition of the fly ash and the portland cement. Currently, States allow a maximum substitution in the range of 15 to 25 percent.

Effects of fly ash, especially Class F, on fresh and hardened concrete properties has been extensively studied by many researchers in different laboratories, including the U.S. Army Corps of Engineers, PCA, and the Tennessee Valley Authority. The two properties of fly ash that are of most concern are the carbon content and the fineness. Both of these properties will affect the air content and water demand of the concrete.

The finer the material the higher the water demand due to the increase in surface area. The finer material requires more air-entraining agent to five the mix the desired air content. The important thing to remember is uniformity. If fly ash is uniform in size, the mix design can be adjusted to give a good uniform mix.

The carbon content, which is indicated by the loss of ignition, also affects the air entraining agents and reduces the entrained air for a given amount of air-entraining agent. An additional amount of air-entraining agent will need to be added to get the desired air content. The carbon content will also affect water demand since the carbon will absorb water. Again uniformity is important since the differences from non-fly ash concrete can be adjusted in the mix design.

Fresh Concrete Workability. Use of fly ash increases the absolute volume of cementitious materials (cement plus fly ash) compared to non-fly-ash concrete; therefore, the paste volume is increased, leading to a reduction in aggregate particle interference and enhancement in concrete workability. The spherical particle shape of fly ash also participates in improving workability of fly ash concrete because of the so-called "ball bearing" effect (Admixtures and Ground Slag for Concrete 1990; ACI Comm. 226 1987c). It has been found that both classes of fly ash improve concrete workability.

Bleeding. Using fly ash in air-entrained and non-air-entrained concrete mixtures usually reduces bleeding by providing greater fines volume and lower water content for a given workability (ACI Comm. 226, 1987c; Idorn and Henrisken, 1984). Although increased fineness usually increases the water demand, the spherical particle shape of the fly ash lowers particle friction and offsets such effects. Concrete with relatively high fly ash content will require less water than non-fly-ash concrete of equal slump (Admixtures and ground slag for concrete, 1990).

Time of Setting. All Class F and most Class C fly ashes increase the time of setting of concrete (Admixtures and ground slag 1990; ACI Comm. 226, 1987c). Time of setting of fly ash concrete is influenced by the characteristics and amounts of fly ash used in concrete. For highway construction, changes in time of setting of fly ash concrete from non-fly-ash concrete using similar materials will not usually introduce a need for changes in construction techniques; the delays that occur may be considered advantageous (Halstead 1986).

Strength and Rate of Strength of Hardened Concrete. Strength of fly ash concrete is influenced by type of cement, quality of fly ash, and curing temperature compared to that of non-fly-ash concrete proportioned for equivalent 28-day compressive strength. Concrete containing typical Class F fly ash may develop lower strength at 3 or 7 days of age when tested at room temperature (Admixtures and ground slag for concrete, 1990; ACI Comm. 226 1987c). However, fly ash concretes usually have higher ultimate strengths when properly cured. The slow gain of strength is the result of the relatively slow pozzolanic reaction of fly ash. In cold weather, the strength gain in fly ash concretes can be more adversely affected than the strength gain in non-fly-ash concrete. Therefore, precautions must be taken when fly ash is used in cold weather (Admixtures and ground slag 1990).

Freeze-thaw Durability of Hardened Concrete. On the basis of a comparative experimental study of freeze-thaw durability of conventional and fly ash concrete (Soroushian 1990; Virtanen 1983; Lane and Best 1982), it has been observed that the addition of fly ash has no major effect on the freeze-thaw resistance of concrete if the strength and air content are kept constant. The addition of fly ash may have a negative effect on the freeze-thaw resistance of concrete when a major part of the cement is replaced by it. The use of fly ash in air-entrained concrete will generally require an increase in the dosage rate of the air-entraining admixture to maintain constant air. Air-entraining admixture dosage depends on carbon content, loss of ignition, fineness, and amount of organic material in the fly ash (ACI Comm. 226, 1987c).

Carbon content of fly ash, which is related to the coal burned by the producing utility of the type and condition of furnaces in the production process of fly ash, influences the behavior of admixtures in concrete. It has been found that high-carbon-content fly ash reduces the effectiveness of admixtures such as air-entraining agents (Joshi, Langan, and Ward 1987: Hines 1985).

Alkali-silica Reaction of Hardened Concrete. One of the important reasons for using fly ash in highway construction is to inhibit the expansion resulting from ASR. It has been found that 1) the alkalies released by the cement preferentially combine with the reactive silica in the fly ash rather than in the aggregate, and 2) the alkalies are tied up in nonexpansive calcium-alkali-silica gel. Thus hydroxyl ions remaining in the solution are insufficient to react with the material in the interior of the larger reactive aggregate particles and disruptive osmotic forces are not generated (Halstead 1986; Olek, Tikalsky, and Carrasquillo 1986; Farbiarz and Carrasquillo 1986).

In a paper presented at the 8th International Conference on alkali-aggregate reactivity held in Japan in 1989, Swamy and Al-Asali indicated that ASR expansion is generally not proportional to the percentage of cement replacement by fly ash. The rate of reactivity, the replacement level, the method of replacement, and the environment all have a profound influence on the protection against ASR afforded by fly ash. Several investigators (Mehta, 1980; Diamond, 1981; Hobbs, 1982) have stated that ASR expansions correlated better with water-soluble alkali-silica contents than with total alkali content. The addition of some high-calcium fly ash containing large amounts of soluble alkali sulfate might increase rather than decrease the alkali-aggregate reactivity (Mehta, 1983). The effectiveness of different fly ashes in reducing long-term expansion varied widely; for each fly ash, this may be dependent upon its alkali content or fineness (Soroushian, 1990).

WHY USE FLY ASH?

As we have seen, there are many practical reasons to add some (if not a lot of) fly ash to concrete–not just in addition to portland cement, but in replacement of it. In Chapter 3, we looked at the performance-enhancing effects of fly ash on workability, pumpability, strength, shrinkage, and permeability. The effects are so many, and so positive, that senior figures in the world of concrete have recently stated that concrete without fly ash belongs in a museum.

This may come as shocking news to many engineers, who remain convinced that fly ash in some way “waters down” the quality of concrete. When, as a junior engineer, I first heard of fly ash in the early 1980s, my supervisor sneeringly referred to it as “hamburger helper” or “filler.” Those early impressions are sometimes hard to change, and they still linger in many parts of the concrete industry. In large part, those impressions are based on decades-old experience using ashes from earlier generations of power plants; those fly ashes were both coarser and higher in carbon residue than those commonly found today, and were thus much less effective as pozzolans. In another case, a 40% fly ash concrete was poured in 1981 for the Monterey Bay Aquarium using a superplasticizer. The project was ultimately successful, but incorrect dosages of the water-reducer caused premature gelling of the concrete; it started to set in the buckets before being emplaced, leaving in many people’s minds the false impression that the high volume of fly ash was to blame. As anyone in construction knows, you can screw up anything if you’re not paying attention, just as you can learn from mistakes (and are foolish if you don’t) if you take the time to study what went wrong. What is generally true in construction is particularly so for concrete: you get what you inspect, not what you expect.

The big picture
Many reasons for using fly ash are global, environmental, or societal in nature. The production of portland cement puts about a ton of carbon dioxide (CO2, a primary greenhouse gas) into the atmosphere for every ton of cement produced–roughly half a ton from the fuel used to cook the raw limestone, and half a ton from the calcination of the limestone. Worldwide, the production of portland cement alone accounts for 6-8% of human-generated CO2 (depending on whom you ask). So here, in a single industry, lies the opportunity to slow the very alarming trend toward global warming. According to one authority:

For every ton of fly ash used [to replace portland cement]–

Enough energy is saved to provide electricity to an average American home for 24 days.
The landfill space conserved equals 455 days of solid waste produced by the average American.
The reduction in CO2 emissions equals 2 months of emissions from an automobile.
The cement industry deserves great credit for recognizing this, and for taking many effective steps to reduce its local and global environmental impacts. But the fact remains that we have a readily available industrial waste product–fly ash–that happens to be a perfect replacement for half or more of the cement in almost any mix, and yields equal or better-quality concrete. This is why high usage of fly ash in concrete is now a component for global trading of so-called “carbon credits,” based on the Kyoto Accords and the Chicago Climate Exchange. Use of fly ash is also a means of making points in the increasingly important LEED™ (Leadership in Energy and Environmental Building) system of evaluating and rating buildings, developed by the US Green Building Council (USGBC). (For more detailed information, see the USGBC website at www.usgbc.org, and appendix C in this book for more elaboration and a sample calculation.)

Most of the fly ash produced today is currently being either landfilled, as in North America where lack of convenient rail spurs hinders bringing it to the marketplace, or simply flying freely out the smokestack of the coal-fired power plant from which it comes, as in China and India. Fly ash in the ground can pollute groundwater with heavy metals, while fly ash in the air constitutes particulate pollution–the bulk of the famous smog blanketing Beijing and many other cities that is a health hazard to everyone nearby. Fly ash trace metals and particulates cast into concrete, by contrast, are bound forever in a way that cannot hurt anyone.

Some in the green building movement question whether increasing the use of fly ash in concrete will effectively encourage coal-fired power production–itself a primary source of environmental degradation, pollution, and greenhouse gases. However, in light of the huge percentage of worldwide electricity generation already derived from coal, and the fact that so little of the ash currently being produced is stored safely in concrete, and the fact that both coal-fired power and concrete production are rapidly increasing along with the population, this seems like a weak argument at best. Current annual world production of cementitious and pozzolanic by-products of thermal power plants and metallurgical industries is about 650 million metric tons, of which only about 7% is being used by the cement and concrete industries. This is beyond wasteful; it is ridiculous. Simple arithmetic shows that coal and other fossil fuels have little or no place in the 100+ year plan for humanity. But for now and the next generation or two, we have the ash and we should use it intelligently. We can go on letting the existing output of fly ash be a landfill, pollution, and health problem, or we can use it to make better concrete.

There is also an enormous economic consideration in using fly ash. Portland cement-based concrete is the most ubiquitous construction material used in the United States and the world; currently more that 118 million tons are poured annually in the US, with fly ash now used to replace over 15 million tons of portland cement per year. Even so, in 2003 over 15 million tons of cement were imported into the US to make up for a shortage of native cement production. If domestic ash had replaced those imports, the result would have been an improvement in the US balance of trade of at least $1 billion. In a similar fashion, populous nations such as Brazil, India, and China are making or importing cement at great cost while grossly underutilizing their own native sources of ash and other industrial pozzolans. Things are, unfortunately, never quite so simple. For example, the cost of installing equipment to collect fly ash at the power plant is huge, and typically deemed uneconomical; what makes good business sense to the power plant owner is a disaster for society. Resolving a disparity like that–striking a balance between unfettered free-market capitalism and the need to protect the public welfare–can only be done in the societal and political arena.

Radically increasing the use of fly ash in concrete–whether blended at the readymix plant, or premixed and bagged at cement plants–is but one component of the broader effort to make concrete a more environmentally friendly building material without sacrificing quality or affordability. Other aspects in development include the use of other industrial by-products as cementitious materials or as components of cement manufacturing, the use of pervious concrete to absorb storm water, the use of light or white concrete to reduce the urban heat-island effect, and the reuse of demolished concrete as aggregate in new structures.

The widespread use of high fly ash concrete is an idea whose time has come. After decades of development in laboratories all over the world, and more recent use in demanding and varied projects, HFAC is now very much in the “real world” of concrete. In the preceding pages you saw how it works, how to use it, and pitfalls to avoid. In the references to follow you will find more technical detail. Here is your start, and some tools to help. Good luck with your projects.

Cool Fly Ash: What is that?

DEFINITION:
Flyash is defined in Cement and Concrete Terminology (ACI Committee 116) as "the finely divided residue resulting from the combustion of ground or powdered coal, which is transported from the firebox through the boiler by flue gases." Flyash is a by-product of coal-fired electric generating plants.

Two classifications of flyash are produced, according to the type of coal used. Anthracite and bituminous coal produces flyash classified as Class F. Class C flyash is produced by burning lignite or subbituminous coal. Class C flyash is preferable for the applications presented in the Green Building Guide and is the main type offered for residential applications from ready-mix suppliers.



--------------------------------------------------------------------------------

CONSIDERATIONS:
Flyash is one of three general types of coal combustion byproducts (CCBP's). The use of these byproducts offers environmental advantages by diverting the material from the wastestream, reducing the energy investment in processing virgin materials, conserving virgin materials, and allaying pollution.

Thirteen million tons of coal ash are produced in Texas each year. Eleven percent of this ash is used which is below the national average of 30 %. About 60 - 70% of central Texas suppliers offer flyash in ready-mix products. They will substitute flyash for 20 - 35% of the portland cement used to make their products.

Although flyash offers environmental advantages, it also improves the performance and quality of concrete. Flyash affects the plastic properties of concrete by improving workability, reducing water demand, reducing segregation and bleeding, and lowering heat of hydration. Flyash increases strength, reduces permeability, reduces corrosion of reinforcing steel, increases sulphate resistance, and reduces alkali-aggregate reaction. Flyash reaches its maximum strength more slowly than concrete made with only portland cement. The techniques for working with this type of concrete are standard for the industry and will not impact the budget of a job.

This section also addresses wall-form products. Most of these products have hollow interiors and are stacked or set in place and then filled with steel-reinforced concrete creating a concrete structure for a house.

Some wall-form materials are made from EPS (expanded polystyrene) which is a lightweight non-CFC foam material. There are also fiber-cement wall-form products that can contain wood waste. The EPS/concrete systems offer high insulating qualities and easy installation. The fiber-cement blocks offer insulating qualities as well. Some EPS products also have recycled content.

Commercial
Status Implementation
Issues

Cementitous Structure

Flyash Concrete

Recycled Content Block

Concrete Finish Floor

Concrete Interior Wall


Legend
Satisfactory

Satisfactory in most conditions

Satisfactory in Limited Conditions

Unsatisfactory or Difficult



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COMMERCIAL STATUS

TECHNOLOGY:
Flyash used in concrete is a mature technology. Thirty percent of the flyash in the US is recycled into making concrete. The use of flyash concrete in structural applications such as wall-forms is standard technology. The use of recycled-content block, in particular fiber-cement, as part of a structural foundation system using flyash concrete is still early in development.
SUPPLIERS:
Approximately 60-70% of central Texas ready-mix suppliers offer flyash concrete. Some suppliers provide it automatically, others give a choice. Recycled-content fiber-cement block should become more available as a regional distributor has been established. EPS wall-form materials are locally and regionally available.
COST:
Flyash concrete is the same price as ordinary concrete without flyash. EPS wall-form products provide a cost-effective wall. Fiber-cement wall-form cost approximately $3.50 per square foot of wall surface.
--------------------------------------------------------------------------------

IMPLEMENTATION ISSUES

FINANCING:
Available.
PUBLIC ACCEPTANCE:
There is a small segment of the population that is fearful of flyash being inferior or unhealthful. U.S. EPA information indicates there is not a health threat, especially in the portions found in ready-mix products and with western coal (which is the primary source of local flyash).
A concrete finish floor may sound less desirable aesthetically to some persons. However, coloring, scoring, and texturing techniques can be very attractive.

Wall-form products should be well-received.

REGULATORY:
Flyash concrete meets applicable codes. Products making use of flyash concrete must indicate having met applicable ASTM test requirements. This information will be provided by the supplier.


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GUIDELINES

1.0 Specification for flyash
Flyash for use in portland cement concrete shall conform to the requirements of ASTM C 618, Standard Specification for Flyash and Raw or Calcined Natural Pozzolan Class C Flyash for use as a Mineral Admixture in Portland Cement. Specifically, it shall conform to all requirements of Table 1 and Table 2 as outlined therein.

The concrete supplier shall furnish a notarized certificate from the flyash marketer at the time of submittal of concrete mix designs for approval indicating conformance with these requirements. Also, a copy of the most recent chemical analysis shall be provided.

At no time during the course of the project will a change of flyash source (plant) be permitted without the prior written consent of the Engineer or Architect. For sulfate environments, only Class F flyash will be permitted and under no circumstances will Class C flyash be used.


2.0 Flyash use.
Class F flyash will typically require an air entraining agent to be added. Class C flyash will not.

Standard concrete procedures can be employed.


3.0 Flyash concrete in poured concrete permanent wall-forms
The use of these systems eliminates the need for conventional framing on exterior walls.


Expanded polystyrene (EPS) wall-forms
Some feature interlocking features and stack like blocks. Some are in rigid panels on interior and exterior connected by metal or steel ties.

EPS blocks are typically stacked as exterior walls. Rebar is placed in the cores vertically and horizontally. The cores are poured full of concrete from the top.

Manufacturers claim R-values of R-30 or greater.

Specify that the foam is protected from insects. Insects will not eat the foam but will nest in it. Borate treatment is preferable.

Urethane block wall-form products are also available. These contain CFC's/HCFC's.


Fiber-cement wall forms.
Can use waste wood; will not burn; insect resistant; will not support condensation.

Approximately R-12 ratings in 9 inch block.

Hollow cores are filled with steel reinforced concrete.

Industrial materials recycling for green buildings

Industrial materials recycling, reuse, also referred to as beneficial use, means reusing or recycling byproduct materials generated from industrial processes. These materials can be used as substitutions for raw materials in the manufacture of consumer products, roads, bridges, buildings, and other construction projects. Thousands of manufacturing and industrial processes and electric utility generators create hundreds of millions of tons of nonhazardous industrial materials that are often wasted.

Nonhazardous industrial materials, such as coal ash, foundry sand, construction and demolition materials, slags, and gypsum, are valuable products of industrial processes. Each material may be recycled in a variety of diverse applications. These materials have many of the same chemical and physical properties as the virgin materials they replace - they can even improve the quality of a product. For example, the use of coal fly ash can enhance the strength and durability of concrete. Putting these commodities into productive use saves resources and energy, reduces greenhouse gas emissions, and contributes to a sustainable future.

Industrial materials recycling:

Preserves our natural resources by decreasing the demand for virgin materials;


Conserves energy and reduces greenhouse gas emissions by decreasing the demand for products made from energy intensive manufacturing processes; and


Saves money by decreasing disposal costs for the generator and decreasing materials costs for end users.
Examples of practical recycling applications include:

Concrete and asphalt crushed and used as an aggregate in pavements or as structural fill;


Coal fly ash, slag, and spent foundry sand recycled in concrete, road embankments, and flowable fill;


Coal ash used in the manufacture of cement and ceiling tiles; and


Flue gas desulfurization gypsum, foundry sand, and pulp and paper byproducts used in manufactured soil and agricultural amendments.
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27 Haziran 2009 Cumartesi

Energy generation to-do list

Tick off the steps to your renewable technology

Installing a renewable technology might seem like a challenge, but it's really no more complicated than any other home improvement.

Just follow these simple steps, from initial research to learning to operate your new energy system.

Getting started
Narrowing it down
Electricity or heating?
Made your decision?
After the installation
Getting started
Find out about your options for generating energy at home:

Read about the different ways to generate your own energy on our renewable technologies pages
See which technologies might suit your home with our energy selector tool - coming soon
Talk to people you know who have installed renewable technologies.
Narrowing it down
You'll need to decide:

which technology to use
what size system to install
which installer and products to use
how to pay for the installation
Here's what to do to help you choose:

See what products are available - research local suppliers and installers online and give them a call to find out more.
Check that the suppliers are certified - either with the Microgeneration Certification Scheme (for all UK microgeneration products and installers) or the Solar Keymark (Solar thermal products and installers across Europe).
Look into funding and financing for the options that interest you - search for grants and offers
Check whether you need planning permission - find your local authority
Get recommendations and quotes - arrange for a few potential installers to visit your home and tell you what they can offer and how much it will cost.
Electricity or heating?
Depending on which you choose, there are other things to thing about:

Electricity: is your home connected to the National Grid? If so, think about selling your own energy. If not, you'll need to research the best way to store electricity.
Heating: is your current heating system compatible with the installation? Could you be more efficient with another type of system, such as under floor heating? Get opinions from a range of certified installers.
Made your decision?
The final details to nail down before you go ahead:

Apply for grants that you¿re eligible for, and make sure you comply with all the conditions. Find out more at the Low Carbon Building Programme website
Make your home energy efficient by installing insulation, double glazing and draught-proofing - this will ensure you get the most out of your renewable technology.
Apply for planning permission if you need it - find your local authority
Make sure you have warranties on your products and installation - it will add to your peace of mind and could cut your future costs. To find out more, talk to your installer.
Find secondary contractors for bore holes, scaffolding etc to get your project off the ground.
After your installation
Don't forget...

Check with your home insurance provider to make sure your policy covers the changes to your home, and make any adjustments you need.
Learn how to use your new system - ask your installer to arrange a training or advice session.

Types of biomass technology

Biomass heating systems can be described by the type of feedstock it needs:
•Feedstock:
oLogs require very little processing other than being sawn to the correct dimensions and being kept dry, or ?seasoned?. Seasoning reduces the moisture content of the wood to about 20% by mass and can take up to three years. These are used in log stoves and boilers
oWood chips are typically derived from waste wood products, and due to the nature of delivering the feedstock to the fire chamber of the boiler, they are better suited to larger applications
oWood pellets undergo the greatest amount of processing of all the biomass products. Because of this pellets boast the advantage of having a very high and consistent energy content whilst having a low moisture content, as well as being more convenient to store, transport and burn

Types of heating system available include:
•Log stoves/boilers which burn logs directly
•Wood chip boilers which burn wood chips
•Pellet stoves/boilers burn wood pellets
•Multifuel stoves can burn a range of solid fuel types
•Ceramic stoves burn wood products and store heat in thermally massive ceramic tiles for release throughout the day

Other biomass technologies include gasification and pyrolysis, but these will not be presented here.

What is biomass?

Biomass is living matter. In terms of domestic renewable energy it is recently living matter which we can easily burn such as wood or other plant material either in its raw state, after very little processing, (e.g. logs) or after more advanced processing (e.g. wood chips or pellets).
Biomass requires sunlight for energy in which to grow, and so can be thought of as another form of indirect solar renewable energy, which has the advantage of convenient storage.

Biomass should be considered as a ?nearly? carbon neutral energy resource. Burning biomass releases no more carbon dioxide than was removed from the atmosphere when it was growing, but there are some emissions from transporting and processing this resource, highlighting the necessity of sourcing biomass fuel from local and sustainable sources.

Typically wood is burnt to release heat for space heating and hot water purposes in the home. To ensure that biomass used in this way is done so sustainably, it is important not to waste energy in order to prevent biomass from being consumed more quickly than it is replenished.

Tips for Saving Energy



Develop a plan to use less electricity.
Call in the Energy Auditors.
Support clean renewable energy.
Replace regular incandesent light bulbs with fluorescent light bulbs.
Install a programmable thermostat.
Move your thermostat down two degrees in the winter and up to degrees in the summer.
Clean or replace your filters on your furnace and air conditioner.
Chose energy efficent appliances when making new purchases.
Turn off electronic devices that you aren't using.
Don't leave electrical equipment on standby.
Unplug electronics from the wall when you're not using them.
Only run your dishwasher when there's a full load.
Dust off the vent grills at the back of computers, refrigerators, TVs and cookers.
Beat draughts. They can be fixed easily with draught-proofing, secondary glazing or double glazing – the UK’s most popular energy saving measure (although you’ll save more money by installing cavity wall insulation, which is cheaper). Specify ‘Low-e’ glazing, which has a special heat-reflective coating that reduces heat loss through the window by nearly half. Find out more at National Energy Foundation.
Shut that Cooker Door! Don’t keep opening the cooker door. Switch your cooker off a few minutes before your food is ready and it’ll stay hot enough to finish cooking the food.
Shut that Fridge Door! Don’t keep opening the fridge door, letting out all the cold air. Keep the fridge full too. It takes less energy to keep a full freezer cool than it does an empty one. Fill it up with water bottles, or other things from your pantry.
Use a clothes line instead of a dryer whenever possible.
Insulate and weatherize you home.
Wrap your water heater in an insulation blanket.
Make sure buildings are energy efficient.
Switch to green power. More...
Use less hot water.
Become a smart water consumer.
Avoid heavily packaged products.
Farmers, turn food into fuel.

Be Energy-Efficient at Home

Most of the 25 tons of CO2 emissions each American is responsible for each year comes from the home. Whether that concerns you, or you simply want to reduce your fuel bills, here are some easy ways to get that number down in a hurry without rebuilding.
Open a window instead of turning on the air-conditioning.
Adjust the thermostat a couple of degrees higher in the summer and lower in the winter.
Caulk and weatherstrip all your doors and windows.
Insulate your walls and ceilings.
Use the dishwasher only when it's full.
Install low-flow showerheads.
Wash your clothes in warm or cold water.
Turn down the thermostat on the water heater.
At the end of the year, don't be surprised if your house feels lighter: it just lost 2 tonnes of carbon dioxide!

Carbon Related Links

Find out more on carbon labelling, credits, footprinting, climate change and who is doing what:
Whether you are a Local Planning Authority, consultancy or an individual, the Institute of Environmental Management and Assessment (IEMA) are the leading provider of Environmental Impact Assessment (EIA) and Strategic Environmental Assessment (SEA) quality assurance services in the UK.
If you would like to find an appropriately qualified auditor to undertake specific environmental auditing, try IEMA auditors at technical@iema.net or telephone (+44) 01522 540069.
Other organisations who can audit a businesses energy use and suggest ways to reduce the energy used for substantial cost savings include The Carbon Trust or Environmental Information Exchange.

Carbon Labelling


Carbon Labelling is being launched in the UK where the number on the label is the amount in grammes of CO2 (and other greenhouse gases) used in the product's manufacture, delivery and disposal. Walkers crisps will be among the first products to carry such a label, along with certain ranges of Boots shampoo and Innocent smoothies. It not only gives information about the carbon 'footprint' of the product, but it shows the company's commitment to reduce the figure. If companies fail to reduce the footprint over a two year period, the label may be withdrawn.

Geern building will increase the Employee satisfaction and productivity





By providing amenities that make your building a healthier and more comfortable place to work, you can reduce employee absenteeism and turnover while increasing productivity. Even small workplace improvements, such as installing individual temperature and ventilation controls, improving the flow of natural light and providing access to a roof garden, can have a big impact on your company's bottom line.


The EPA estimates that building-related illnesses account for $60 billion in annual productivity lost nationwide. And according to a University of Wisconsin study, tangible costs of hiring and retaining a new employee typically range between $10,000 and $50,000 -- plus less quantifiable, but no less real, productivity costs as employees adapt to the new work environment and cultivate relationships with clients, coworkers, contractors, etc. With less absenteeism and greater employee retention, your investments in green building features will quickly pay for themselves.

In a 2004 survey of 719 building owners, developers, architects, engineers and consultants, Turner Construction found that 91 percent of executives involved with green buildings believed that the health and well-being of their building occupants was greater.


By installing skylights, fluorescent light fixtures and additional insulation to improve lighting and temperature control, Verifone's credit card verification facility in Costa Mesa, California, decreased its energy consumption 59 percent, reduced employee absenteeism by 47 percent and boosted productivity by 5 percent to 7 percent.


At the headquarters of the West Bend Mutual Insurance Company in West Bend, Wisconsin, green features including individual workstation controls for temperature, airflow, lighting and noise contributed to a 15 percent increase in claims processing per employee.

Lower your maintenance and operating costs

By paying an average of 2 percent up front on efficient green features, you can save as much as 30 percent to 40 percent on your energy and water bills. And trimming your operating and maintenance costs -- which can account for up to 85 percent of your building's lifetime costs -- pays back any upfront premium in construction expenses in a few years. By saving on operations and maintenance, you can generate increased cash flow and higher margins.


With the help of a task/ambient lighting strategy and abundant daylighting, NRDC's New York office uses less than 0.4 watts per square foot in lighting-related power, 60 percent below the current baseline usage of 1 watt per square foot for new buildings.


By recalibrating equipment, introducing new startup and shutdown procedures and making other efficiency improvements, Salt Lake City's Matheson Courthouse reduced its energy costs from $1.08 per square foot to $0.77 per square foot annually.

By building green, you can:

Keep pollution from power plants out of the air by reducing energy consumption by as much as 70 percent and by making use of wind or solar power. For every $1.00 per square foot you save in electricity costs, you will keep 1 ton of carbon dioxide out of the air.


Eliminate the energy, materials and other environmental costs associated with building new infrastructure.


Potentially reduce vehicle-related air pollution by cutting commuting distances by 30 percent or more through location efficiency.


Prevent pollution from washing into waterways and swimming areas by cutting stormwater outflows by 50 percent or more.


Reduce potable water consumption by 50 to 70 percent.


Help keep forests intact and promote the vitality of forest ecosystems by specifying certified forest products and using agriculturally based products.


Promote biodiversity and limit pollution from harmful pesticides and fertilizers by landscaping with native plants instead of exotic varieties.

Building green offers to polish your public image

Building green offers you a great way to boost your profile as a good corporate citizen -- in the eyes of your employees and your community. Getting your project certified through the U.S. Green Building Council's LEED green building rating system can help earn free publicity for your achievement and your business. LEED certification also provides proof to you, your employees and the public that you have achieved your sustainability goals.

At the same time, studies show that green building features such as abundant natural light, superior indoor air quality, views of the outdoors and landscaped surroundings help keep employees satisfied and increase productivity -- allowing you to attract and retain the best talent.

Tips for Getting LEED Certified

Set a clear environmental target. Before you begin the design phase of your project, decide what level of LEED certification you are aiming for and settle on a firm overall budget. Also consider including an optional higher certification target -- a "stretch" goal -- to stimulate creativity.


Set a clear and adequate budget. Higher levels of LEED certification, such as Platinum, do require additional expenditure and should be budgeted for accordingly


Stick to your budget and your LEED goal. Throughout out the design and building process, be sure your entire project team is focused on meeting your LEED goal on budget. Maintain the environmental and economic integrity of your project at every turn.


Engineer for Life Cycle Value As you value-engineer your project, be sure to examine green investments in terms of how they will affect expenses over the entire life of the building. Before you decide to cut a line item, look first at its relationship to other features to see if keeping it will help you achieve money-saving synergies, as well as LEED credits. Many energy-saving features allow for the resizing or elimination of other equipment, or reduce total capital costs by paying for themselves immediately or within a few months of operation. Prior to beginning, set your goals for "life cycle" value-engineering rather than "first cost" value-engineering.


Hire LEED-accredited professionals. Thousands of architects, consultants, engineers, product marketers, environmentalists and other building industry professionals around the country have a demonstrated knowledge of green building and the LEED rating system and process -- and can assist you in meeting your LEED goal. These professionals can suggest ways to earn LEED credits without extra cost, identify means of offsetting certain expenses with savings in other areas and spot opportunities for synergies in your project.

How does one achieve LEED certification?

The U.S. Green Building Council's LEED website provides tools for building professionals, including:

Information on the LEED certification process.
LEED documents, such as checklists and reference guides. Standards are now available or in development for the following project types:
New commercial construction and major renovation projects (LEED-NC)
Existing building operations (LEED-EB)
Commercial interiors projects (LEED-CI)
Core and shell projects (LEED-CS)
Homes (LEED-H)
Neighborhood Development (LEED-ND)
A list of LEED-certified projects
A directory of LEED-accredited professionals
Information on LEED training workshops
A calendar of green building industry conferences

What are the benefits of LEED certification?

LEED certification, which includes a rigorous third-party commissioning process, offers compelling proof to you, your clients, your peers and the public at large that you've achieved your environmental goals and your building is performing as designed. Getting certified allows you take advantage of a growing number of state and local government incentives, and can help boost press interest in your project.

The LEED rating system offers four certification levels for new construction -- Certified, Silver, Gold and Platinum -- that correspond to the number of credits accrued in five green design categories: sustainable sites, water efficiency, energy and atmosphere, materials and resources and indoor environmental quality. LEED standards cover new commercial construction and major renovation projects, interiors projects and existing building operations. Standards are under development to cover commercial "core & shell" construction, new home construction and neighborhood developments.