NDCEE Joint Service Environmental Management Conference. Cold Weather Admixture Systems (CWAS)

Transcription

1 DoD Executive Agent Office of the Assistant Secretary of the Army (Installations and Environment) Transferring Technology Solutions - Cold Weather Admixture Systems (CWAS) NDCEE 2006 Joint Service Environmental Management Conference Michael Muthig, Ph.D. Concurrent Technologies Corporation National Defense Center for Environmental Excellence Operated by: Supporting Readiness, Sustainability, and Transformation

2 Presentation Outline Technology Description Applications & Benefits Discovery & Development Demonstration/Validation Overview of Activity by NDCEE Military Review & Industry Standards Summary Acknowledgements References Points of Contact 2

3 Commercialization of Technologies to Lower Defense Cost Program Goals Facilitating technology transfer & commercialization Expediting acquisition to lower defense costs Focus Areas Environmental compliance & restoration Pollution prevention and conservation Three Phased Approach Phase I Needs identification and initial technology evaluation Phase II In-depth assessment and demonstration/validation planning Phase III Demonstration/validation & business strategy implementation 3

4 Technology Description Definition Cold Weather Admixture Systems (CWAS) are any commercial admixture or combination of admixtures that depress the freezing point of mixing water and accelerate the hydration rate of Portland cement in concrete. The term antifreeze admixture may be used interchangeably for CWAS. Modified from Air Force Engineering Technical Letter 05-8 Photo from Korhonen & Semen

5 Technology Description Function of CWAS The primary functions are to prevent concrete from freezing at internal temperatures as low as -5 C and to promote strength gain at that temperature at least as fast as normal concrete cured at 5 C. Temperature(C) C Strength PSI Control 20C 5C 5C Antifreeze 20C Control Antifreeze Mix 1 Freeze Point Days Function modified from Air Force Engineering Technical Letter Figures from Korhonen & Semen (Minutes) 5

6 Applications for CWAS Potential uses of CWAS include placement of concrete in winter conditions with application to general construction, emergency repair, and use for commercial and military concrete construction. Curbing Horizontal surfaces Roadways Airfield pavement Photo from Korhonen & Semen Footings Photos from Korhonen & Others 2004

7 Benefits Reduces cost Reduces or eliminates fuel use Eliminates or reduces air emissions Extends the concrete season Enhances productivity Accelerates curing Enhances freeze/thaw resistance Shown effective to -20 C Placement without thawing substrates Reduces time and man hours In-place Cost $/m Days 120 Days Year Round Summer Antifreeze Winter Figures from Korhonen & Semen 2005 S1

8 Technology Comparison Conventional Winter Pour Cold Weather Admixture Erect shelter: 96 man hours Dismantle: 36 man hours Materials: 48 2x4x8 120 m 1x8 120 m strapping 2 rolls poly Heat: 1378 L propane ($748) Admixture 1: $ 58.69/m 3 Admixture 2: $ 3.52/m 3 Admixture 3: $ 52.34/m 3 Total admixture cost: $ From Korhonen & Others 2004

9 Discovery & Development Discovered by researchers at CRREL : Initial research 1997: Emergency pour : Structured study extensive lab work : Initial field trials Compressive strength summary Revolving drum mixer in laboratory 9 Photos & figure from Korhonen & Others 2004

10 Demonstration/Validation Littleton, NH, Dec 2001, Bridge curbing Rhinelander, WI, Feb 2002, Pavement section North Woodstock, NH, Dec 2002, Bridge footing West Lebanon, NH, Dec 2002, Bridge curbing Concord, NH, Feb 2003, Sidewalk New York, NY, Feb 2004, Streets and sidewalks Grand Fork AFB, ND, Feb 2004, Airfield pavement Placing & raking Screeding top layer Floating Brooming 10 Photos from Korhonen & Semen 2005

11 Commercialization of Technologies to Lower Defense Cost Program Goals Facilitating technology transfer & commercialization Expediting acquisition to lower defense costs Focus Areas Environmental compliance & restoration Pollution prevention and conservation Three Phased Approach Phase I Needs identification and initial technology evaluation Phase II In-depth assessment and demonstration/validation planning Phase III Demonstration/validation & business strategy implementation 11

12 Overview of Activity by NDCEE Identified as candidate technology in 2000 Determined that an ASTM standard was a critical component for commercialization Assembled a group to develop a draft standard Presented a draft standard to ASTM in 2003 Supported demonstration at Grand Forks AFB Supported efforts for an Air Force Engineering Technical Letter (issued in 2005) Facilitated rapid ASTM approval (published 2005) Continued efforts focus on finding opportunities for DoD and commercial use and transfer to the private sector 12

13 Military Review & Industry Standards Placing Antifreeze Concrete at Grand Forks Air Force Base, US Army Corp of Engineers, ERDC/CRREL TR-05-9 Use of Off-the-Shelf Concrete Admixtures as Cold Weather Admixture Systems (CWAS), Engineering Technical Letter 05-8, Air Force Civil Engineering Support Center Standard Specification for Cold- Weather Admixture Systems, C1622/C1622M-05, ASTM International 13

14 Summary Cold Weather Admixtures depress freezing point and accelerate hydration Allows concrete to set at concrete temperatures down to -5 C Benefits include reduced cost, labor, fuel use, and air emissions Discovery and development of the technology by CRREL Various successful demonstrations completed Air Force Engineering Technical Letter issued ASTM standard approved Opportunities sought for DoD and commercial use and transfer to the private sector 14

15 Acknowledgements NDCEE Executive Agent Mr. Tad Davis, DASA (ESOH) NDCEE Program Director Mr. James Dries, ODASA (ESOH) NDCEE Program Manager Dr. Charles Lechner, ODASA (ESOH) Government Technical Hany Zaghloul, ASA (ESOH) Monitor NDCEE Project Manager Richard Mirsky, CTC CRREL Team Leader Charles Korhonen, Ph.D., P.E. 15

16 References ASTM International, 2005, C1622/C1622M-05: Standard Specification for Cold-Weather Admixture Systems. Department of the Air Force, Civil Engineering Support Center, 2005, Use of Off-the-Shelf Concrete Admixtures as Cold Weather Admixture Systems (CWAS), Engineering Technical Letter Korhonen, C. and Semen, P., 2005, Placing Antifreeze Concrete at Grand Forks Air Force Base, US Army Corp of Engineers, ERDC/CRREL TR Korhonen, C, Semen, P., and Barna, L., 2004, Extending the Season for Concrete Construction and Repair, US Army Corp of Engineers, ERDC/CRREL TR

17 Points of Contact Hany Zaghloul, ASA (ESOH) Government Technical Monitor (217) Rich Mirsky, Project Manager Manager Concurrent Technologies Corporation Michael G. Muthig, Ph.D. Concurrent Technologies Corporation Charles Korhonen, Ph.D., P.E. US Army Corps of Engineers Cold Regions Research and Engineering Laboratory