Addressing Fly Ash Shortage with Limestone Calcined Clay Cement

Details

• Creators:
  Arce, Gabriel A. ; Jiang, Zhangfan ; Behravan, Amir ; Peterson, Lisa Colosi ; Ozbulut, Osman E.
• Corporate Creators:
  Virginia Transportation Research Council (VTRC) ; University of Virginia
• Corporate Contributors:
  Virginia. Department of Transportation
• Subject/TRT Terms:
  Ash Content Blended Cement Calcined Aggregates Calcined Clay Cement Clay Coal Coal Ash Concrete Limestone Calcined Clay Cement (LC3) Limestone Soils Pozzolan Slag Cement Supplementary Cementitious Materials (SCMs)

  More +
• Publication/ Report Number:
  VTRC 26-R52
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Virginia
• Edition:
  Final Report: 6/15/2023–3/31/2026
• Corporate Publisher:
  Virginia Transportation Research Council (VTRC)
• Abstract:
  Virginia and many other states are experiencing increasing challenges related to the availability of traditional supplementary cementitious materials (SCMs), particularly fly ash. These shortages—with both seasonal and regional variability—threaten the consistency, cost, and performance of concrete used in the Virginia Department of Transportation’s (VDOT) infrastructure. At the same time, an increasing emphasis is on reducing the environmental footprint of cement and concrete production, which necessitates the use of SCMs to reduce the global warming potential associated with clinker manufacturing. Calcined clays have emerged as promising alternative SCMs that may address both material supply constraints and sustainability objectives. However, their suitability for VDOT concrete—including effects on fresh properties, strength, durability, and environmental performance—had not been evaluated. This study was initiated to generate the data and guidance needed for informed decision making regarding the adoption of calcined clays in VDOT applications. This study evaluated limestone calcined clay cement, or LC3—a ternary blended cement typically composed of 50% clinker, 30% calcined clay, 15% limestone, and 5% gypsum—and LC2, a cementitious system similar to LC3 produced by replacing 30% of Portland limestone cement (Type IL) with calcined clay. The fresh, mechanical, durability, and shrinkage characteristics of concrete incorporating LC3 and LC2 were assessed and compared with mixtures containing Class F coal ash and slag cement commonly used in VDOT concretes. In addition, the physical, chemical, and reactivity properties of SCMs were characterized, and global warming potential analyses were conducted to quantify the potential environmental benefits associated with incorporating calcined clay. Together, these evaluations provide a comprehensive framework for understanding the suitability of calcined clays for VDOT concrete.
• Format:
  PDF
• Collection(s):
  Federal Highway Administration
• Main Document Checksum:
  urn:sha-512:0e59ab7f737a728c44f9419354be9e5db2c7c02cd0c34090784844bc5ae9ef1e9545d69df360c913a299162c23d2d4246c5b830ef6c3103b68e0c9f66937c78d
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/92440/dot_92440_DS1.pdf
• File Type:
  [PDF - 3.43 MB ]