Strategies for Improving Low-CO2 Cements

The mounting concerns of population growth and global climate change are placing increasing pressure on the construction industry to reduce CO2 emissions. Portland cement concrete, which is the world's most widely used building material, is responsible for up to 5% of all man-made CO2 emissions. Significant emissions come from the energy used to heat the cement kilns to the extremely high temperatures required to make cement clinker and also from the decomposition of calcium carbonate (limestone), the main raw ingredient of Portland cement. Lafarge, the world's largest cement manufacturer with a significant presence in both Europe and North America, is taking a serious stance on this issue, committing to reduce global CO2 emissions per mass of cement by 20% by 2010. Although obtaining this target is by no means trivial, they predict that even more ambitious targets will need to be reached in the very near future. This challenge will not only affect cement manufacturers: the building community as a whole will be expected to routinely design, specify, and build in a more sustainable manner. The objectives of this program are as follows: 1. To quantitatively measure, as a function of Ca/Si ratio and hydration time, basic structural properties of C-S-H in cement paste such as density, specific surface area, water content of C-S-H, and shrinkage behavior on drying. 2. To exploit these results to develop an extended structural model of C-S-H that describes the structural changes in C-S-H as a function of composition. 3. To exploit the new understanding of the both the C-S-H structure and the hydration kinetics to activate the hydration process to achieve rapid early strengths in low-CO2 cement systems.

Language

• English

Project

• Status: Completed
• Funding: $215734.62
• Contract Numbers:

  610 4742000 60020784

  A228

• Sponsor Organizations:

  Infrastructure Technology Institute (ITI)

  Northwestern University
  L260 Technological Institute, 2145 Sheridan Road
  Evanston, IL  United States  60208-3109
• Principal Investigators:

  Thomas, Jeffrey

  Jennings, Hamlin

• Start Date: 20080307
• Expected Completion Date: 0
• Actual Completion Date: 20090831
• Source Data: RiP Project 16990

Subject/Index Terms

• TRT Terms: Air quality management; Construction industry; Environmental impacts; Limestone; Pollutants; Portland cement; Research projects
• Subject Areas: Construction; Highways; Pavements; Safety and Human Factors; I15: Environment;

Filing Info

• Accession Number: 01468445
• Record Type: Research project
• Source Agency: Infrastructure Technology Institute (ITI)
• Contract Numbers: 610 4742000 60020784, A228
• Files: UTC, RIP
• Created Date: Jan 3 2013 3:51PM