Dean Frank , Director en Dean Frank Associates

1. Sustainable Aspects of Precast Concrete
Dean Frank, P.E., LEED Green Associate

2. Introduction
• Sustainable aspects of precast concrete
• Precast/Prestressed Concrete Institute (PCI)
best practices for:
• Quality
• Sustainable plant
operations

3. Link Between Quality and Sustainability
• Precast is an inherently sustainable material
• Improving quality and production processes can
make it better

4. Link Between Quality and Sustainability
Precast concrete is made:
• In a quality-controlled environment
• Uses materials efficiently
• Less construction waste

5. Link Between Quality and Sustainability
• Quality processes have a direct effect on the
degree to which precast concrete is considered
sustainable
• As quality improves, so do the sustainable
attributes

6. Link Between Quality and Sustainability
Durability:
• Higher quality
concrete = better
durability
• Durable concrete is
resilient to natural
and man-made
disasters

7. Link Between Quality and Sustainability
Durability:
• Better protection of reinforcement
• Prequalification of raw materials
• Optimization of concrete mix proportions

8. Link Between Quality and Sustainability
Reduced number of defective products
• Primary goal of QA program is to reduce
defects and rejected product

9. Link Between Quality and Sustainability
Reduced waste
• Due to control of raw materials
• Waste is more likely to be recycled
• Process water may be treated and reused
• Forms are reused

10. Link Between Quality and Sustainability
Optimum use of raw materials
• Precise batch quantities are possible
because of tight product tolerances
• Smaller members, longer spans, and less
material used on site = $ and environmental
savings

11. Plant Quality Operations
• Quality assurance and certification programs
played an important role in success of precast
concrete industry
• With more emphasis on sustainability, these will
become even more important

12. Plant Quality Operations
Quality control personnel be more involved with
tracking and coordinating processes that affect
the sustainability
• Raw material prequalification and tracking
• Accelerated curing with added heat or steam

13. Plant Operations
• Industry stakeholders demand improvement
• Can not improve something that is not
measured
• Precasters can also save money

14. Life Cycle Assessment
• What is an Life Cycle
Assessment (LCA)?
• Why LCA?
• Precast Concrete
Building LCA
• LCA Results
• Conclusions

15. What is LCA?
• Environmental accounting of environmental
impact
• Full assessment, rather than single criterion.
• Scientific, not subjective

16. What is LCA?
• Includes environmental effects due to:
• Extraction and fuel
• Manufacture of components
• Transportation
• Assembly and construction
• Operation
• Demolition, disposal, recycling, and reuse
http://www.bre.co.uk/greenguide/page.jsp?id=2106

17. What is LCA?
• Impacts quantified:
• Global warming potential
• Acidification potential
• Potential respiratory effects
• Eutrophication potential
• Photochemical smog creation potential
• Ozone depletion potential

18. What is LCA?
• Additional Inventory Items Tracked:
• Total primary energy
• Solid waste
• Water use
• Abiotic resource depletion

19. Why LCA?
• Increase transparency /
improve operations
• Benchmark precast
concrete industry’s
environmental performance
• Provide data for future
Environmental Product
Declarations (EPDs)

20. Precast Concrete Building LCA
Precast/Prestressed
Concrete Institute (PCI),
the Canadian
Precast/Prestressed
Concrete Institute (CPCI)
and the National Precast
Concrete Associate
(NPCA) partnered to
coordinate this research

21. Functional Unit
• Five-story commercial
office building
• Meets minimum
building energy code
requirements for R-
value
• Conditioned office
space for
approximately 130
people
Actual Building
Building Model

22. Building Form
• Plan dimensions
27 by 36 m (90 by 120
ft)
• Column grid spacing
9 by 12 m (30 by 40 ft)
• Total floor area
5000 m2 (54,000 ft2)
Elevation
Floor plan

23. LCA Study “Scenarios”
• 5 variations of building envelope
• 3 variations of structural framing
• 4 locations (Miami, Phoenix, Memphis, Denver)
Total of 60 buildings
Envelope and abbreviation
Structure and abbreviation
Steel (S)
Cast in place
concrete (C)
Precast
concrete (P)
Curtain wall (CW) CW-S CW-C CW-P
Brick and steel stud (S) S-S S-C S-P
Precast concrete (P) P-S P-C P-P
Insulated precast concrete (Pi) Pi-S Pi-C Pi-P
Insulated precast concrete and
thin-brick veneer (Pib)
Pib-S Pib-C Pib-P
“Baseline”

24. Comparative LCA
• Because this LCA study includes a comparative
assertion disclosed to the public, an independent
external panel of LCA and technical experts has
critically reviewed the methodology and results as
required by ISO 14044:2006.
• The research was conducted by a team comprised of
Morrison Hershfield, the Athena Institute, and Venta,
Glaser & Associates.
• Most comprehensive LCA study undertaken

25. Comparative LCA
• Data for all products was treated equally
• All buildings were compared using the same
functional unit and equivalent methodological
considerations:
• system boundary
• data quality
• allocation procedures
• decision rules on
evaluating inputs and
outputs
• impact assessment

26. Comparative LCA
In comparative assertions similar data quality:
• Time-related coverage
• Geographical coverage
• Technology coverage
• Precision
• Completeness
• Representativeness
• Consistency
• Reproducibility
• Sources of the data
• Uncertainty of the information

27. LCA Results
Good Data:
• Manufacturer data (9
precasters)
• PCA reports with LCI
data on cement and
concrete
• U.S. LCI database
(NREL)

28. LCA Results – Global Warming Potential

29. LCA Results – Global Warming Potential

30. LCA Results – Global Warming Potential

31. LCA Results – Global Warming Potential

32. LCA Results – Total Primary Energy

33. LCA Results – Total Primary Energy

34. LCA Results – Total Primary Energy

35. LCA Results – Total Primary Energy

36. LCA Results
Similar results for:
• Acidification Potential
• Potential Respiratory Effects
• Eutrophication Potential
• Photochemical Smog Creation Potential
• Solid Waste
All within 0 to 2% COV

37. LCA Results – Water Use
0
5
10
15
20
25
30
35
40
45
CW-S
CW-C
CW-P
S-S
S-C
S-P
P-S
P-C
P-P
Pi-S
Pi-C
Pi-P
Pib-S
Pib-C
Pib-P
Wateruse,cubicmeters
Denver, 73 years
0
5
10
15
20
25
30
35
40
45
CW-S
CW-C
CW-P
S-S
S-C
S-P
P-S
P-C
P-P
Pi-S
Pi-C
Pi-P
Pib-S
Pib-C
Pib-P
Wateruse,cubicmeters
Memphis, 73 years
0
5
10
15
20
25
30
35
40
45
CW-S
CW-C
CW-P
S-S
S-C
S-P
P-S
P-C
P-P
Pi-S
Pi-C
Pi-P
Pib-S
Pib-C
Pib-P
Wateruse,cubicmeters
Miami, 73 years
0
5
10
15
20
25
30
35
40
45
CW-S
CW-C
CW-P
S-S
S-C
S-P
P-S
P-C
P-P
Pi-S
Pi-C
Pi-P
Pib-S
Pib-C
Pib-P
Wateruse,cubicmeters
Phoenix, 73 years

38. LCA Results
Similar results for:
• Abiotic Resource Depletion (COV = 36%)
• Ozone Depletion Potential (COV = 0 to 15%)
http://guardianlv.com/2014/03/ozone-depletion-due-to-gases-banned-27-years-ago/
http://www.businessgreen.com/bg/analysis/2280429/ccc-shrinking-water-sources-put-uk-food-
production-at-risk/

39. LCA Conclusions
• Occupancy stage (operating energy) is
responsible for up to 96 to 98% of the
environmental impacts in a given impact
category regardless of climate
• Confirmed there is relatively little difference
between the various structural systems

40. LCA Conclusions
• Contrary to claims often made by other
building materials
• Concrete likely has the most potential to make
improvements

41. NAPCSPP Sustainable Plant Program
North American Precast Concrete Sustainable
Plant Program (NAPCSPP)
• Launched in 2015
• CPCI
• NPCA
• PCI

42. NAPCSPP Sustainable Plant Program
• Environmental Performance Standards
• Dust Control
• Process Water, Storm Water and Chemical
Management
• Noise Control
• Sustainability Performance Standards
• Energy
• Materials
• Transportation
• CO2 equivalent
• Total Primary Energy
• Water Consumption

43. Product Category Rule Development
Progress..
• LCA Complete
• Next Step = Develop PCR
• Same Industry Partners (CPCI, NPCA, PCI)
• ASTM International
• PCR Published on ASTM Website

44. Environmental Product Declarations
Progress..
• PCR Complete
• Gather Data with NAPCSPP
• Next Step = Develop EPDs
• Architectural and Insulated Wall Panels,
• Structural Precast Concrete Products and
• Underground Precast Concrete Products

45. Strategies for Environmental
Improvements
Energy Conservation:
• Alternate lighting, reducing fixtures,
increasing natural daylighting, etc.
• Optimize power factors motors
• Investigate onsite renewable energy

46. Strategies for Environmental
Improvements
Energy Conservation:
• Modify personnel behaviors and use of
natural ventilation
• Building envelope in good condition
• Improvements to HVAC

47. Strategies for Environmental
Improvements
Effective waste management:
• Waste audit
• Reduce or eliminate waste products

48. Strategies for Environmental
Improvements
Effective waste management:
• Reuse or repurpose waste product
• Pour leftover or waste concrete into
reusable forms
www.concreteconstructionweely.com

49. Strategies for Environmental
Improvements
Maximizing materials recycling:
• Divert as much recyclable material as
possible
• Reduce the amount of waste packaging

50. Strategies for Environmental
Improvements
Water management:
• Harvest rain water
• Use closed-loop systems for precast
operations

51. Strategies for Environmental
Improvements
Water management:
• Water conservation program
• Install water meters - quantify how much
water is being used and where.

52. Strategies for Environmental
Improvements
Water management:
• Install low-flow water fixtures
• Ensure irrigation systems do not over-water
or water non-vegetative surfaces
http://deervalleyplumbingsurprise.com/

53. Strategies for Environmental
Improvements
Mix design and optimization:
• Review concrete strength needs and revise
mix designs
• Increase the use of supplemental
cementitious materials

54. Strategies for Environmental
Improvements
• There are many other strategies to consider
• These metrics should be tracked over time

55. Precast Concrete is Well-Positioned
Concrete and precast concrete has great
potential to improve
• PCI Life Cycle Assessment Project
• As plants improve, so will sustainability
• Reduction in usage of portland cement

56. Conclusion
• Precast concrete is comparable to structural
steel…currently
• Both quality and sustainable plant practices
contribute to energy and materials savings and
reduction of environmental impacts

57. Conclusion
• It is best to track performance to improve
transparency and make improvements
• Although precast concrete is inherently
sustainable material, better quality assurance,
plant operation improvements, reduced
Portland cement usage will lead to better
environmental performance