MIT Concrete Sustainability Hub

1. MIT Concrete SustainabilityHub Bruce McIntosh, Portland CementAssociation

2. Topics • HUB background • Life-cycle assessment of pavement • Life-cycle assessment of buildings and homes • Econometrics • Green concrete science

3. MIT Concrete Sustainability Hub • Established by PCA and RMCREF • $10 million investment over next 5 years • Validate and innovate: • Identify areas in which concrete excels • Identify opportunities for improvements • Create solid technical basis for future industry development

4. R&D Platforms • Concrete Science • Building Technology • Econometrics

5. Concrete Science Platform • Mission: Scientific breakthroughs toward reducing CO2 footprint of cement and concrete • Breakthroughs would imply: • Strength with less material • Lower energy processing • Chemical stability

6. Building Technology Platform • Mission: Life-cycle assessment (LCA) of concrete buildings and pavements to identify impacts and opportunities

7. Econometrics • Mission: Assess the impact on jobs and the economy of sustainable advancements in cement and concrete

8. Building Technology: Paving • 8 million lane-miles • 3 trillion vehicle-miles / year • 27% of U.S. GHG emissions from road transportation

9. Improving Paving Performance • Comprehensive methodology for pavement LCA • Quantifying greenhouse gases • Investigate pavement-vehicle interaction

10. Life-Cycle Analysis Opportunities from LCA: • “Cradle-to-cradle” analysis • Large impacts beyond initial manufacturing • Use-phase impacts

11. Use-Phase Impacts • Fuel consumption • Urban heat islands • Street lighting • Carbonation

12. Indirect impacts • Traffic delays • Additional materials and energy • Construction equipment emissions • Material waste

13. Key findings • Whole life LCA needed to capture all impacts • Use and maintenance phases account for 33% to 44% of CO2 for interstate highways

14. Pavement-Vehicle Interaction • Demonstrates of fuel savings with concrete • Two factors: stiffness and roughness Stiffness Roughness

15. Stiffness or Deflection • Rigid pavements produce less rolling resistance and better fuel economy Stiffness

16. Stiffness or Deflection • Asphalt roads need to be 25% to 60% thicker to achieve same fuel efficiency as concrete. • Goal is to assess impacts of pavement properties on fuel consumption for both environmental impact and cost savings.

17. High Volume Arterial 50-year GHG Emissions

18. Building Technology:Structures • Life-cycle analysis research for single-family housing, multifamily housing, and commercial structures

19. Why are Buildings Important? 18% Commercial Bldgs 21% Residential Bldgs 56% 26% Transportation 25% 19% Industry 35% United States Other of G7 countries Rest of the world

20. Buildings Life-Cycle Analysis • Examining materials within whole building context, not just manufacturing and initial construction • Consider use and operations phases

21. Single-Family Housing • Single family homes represent 80% of total residential energy consumption Multi-family 80% Single family

22. Single-Family LCA • Exterior walls • Wood frame and insulating concrete forms • Quantity of insulation • Thermal mass

23. Key Findings • Concrete homes produce 5% to 8% lower GHG emissions. • Concrete homes use 8% to 11% less energy. • Concrete wall systems have higher embodied energy, but that accounts for only 2% to 12% of GHG over a 60-year service life.

24. Next Steps: Air Tightness • Not considered in initial study, but represents greatest potential for additional improvement • Improvement from average to tight saves 23% of total operating energy

25. Commercial Buildings • Commercial buildings represent 18% of U.S. energy consumption

26. Commercial LCA • Compares steel and concrete structural frames • Floor to floor heights identical • 12-story building with 40% glazing 12-

27. Key Findings • No greater embodied energy than comparable steel frames • Energy savings when concrete frame is exposed are 3%; when covered by finishes, 2%. • Active use of the thermal mass capability of concrete slabs could result in significant savings

28. Econometrics • Study on life-cycle cost analysis” for highways, “The Effects of Inflation and Its Volatility on the Choice of Construction Alternatives.” • Study examines historical data on real prices of construction materials.

29. Key Findings • Traditional analysis uses the same escalation rate for concrete and asphalt . • Assumption of constant real costs can lead to serious cost overruns. • Study suggests the use of material-specific escalation rates.

30. Advocacy and Promotion • Working with state and federal officials to incorporate MIT findings in life-cycle analysis models • Focus of ad campaign • Goal: Level playing field for concrete and asphalt.

31. Ad Campaign

32. Concrete Science Platform • Alite/belite reactivity • Aluminate reactivity • Alkali effects • Water and dissolved components • Mechanical properties of materials

33. Concrete Science Platform • Industry/MIT collaboration • Significant progress on key topics: • Alite/belite reactivity • Water and dissolved components • Mechanical properties of materials

34. More Information • http://web.mit.edu/cshub/

35. MIT Concrete SustainabilityHub Bruce McIntosh, Portland CementAssociation