Duracem Evaluation for Kansas Paving Applications

Addition of fly ash to Portland cement concrete mixtures has been known to improve the transport properties and durability of concrete and the offset in cement usage reduces the eventual carbon footprint of the concrete. However, reduction in dependence on coal for power generation and frequent changes in scrubbing procedures for obtaining fly ash from power plant exhaust gasses has introduced uncertainty in the quantity and quality of fly ash available for paving concrete. In particular, the variation in the quantity and type of the unburnt carbon or active carbon, and sulfate phases in fly ash is known to negatively impact air entrainment and setting behavior, respectively, leading to undesirable concrete performance. Unlike fly ash and other industrial byproduct pozzolans, calcined natural pozzolans such as calcined clay or calcined shale can be manufactured with careful industrial process and quality controls, and the raw materials needed to produce them are locally abundant. In compliance with the Roadmap to Carbon Neutrality released by the Portland Cement Assocation, cement producers (like Ash Grove) are scaling up testing and production of binary and/or ternary cements that contain up to 40% calcined natural pozzolans. Ash Grove markets such cements under the brand name "Duracem." Therefore, the use of Duracem for pavement concrete application needs to be evaluated. Numerous studies have been conducted to understand the hydration process and quantify the mechanical and fresh properties of concrete prepared using binary and/or ternary cements containing calcined natural pozzolans and/or limestone. Some of those studies show that concrete containing calcined natural pozzolans have comparable mechanical and fresh properties to that of concrete prepared using Type I/II OPC cement. However, large scope studies evaluating the freeze-thaw durability, permeability, shrinkage behavior, and admixture compatibility of concrete prepared using binary and/or ternary (third ingrediant being ground limestone) cements containing calcined natural pozzolans are warranted. Our industry partner Ash Grove Cement found this proposed work intriguing, and expressed strong interest providing a cement producer's insights and in-kind support. Given the ongoing concrete durability challenges in the State of Kansas, evaluating the aforementioned properties of concrete prepared using Duracem will provide KDOT with the technical basis to assess the suitability for use in Kansas paving applications.

Language

• English

Project

• Status: Active
• Funding: $96770
• Contract Numbers:

  KSU-23-6

  RE-0863-01

  C2208

• Sponsor Organizations:

  Kansas Department of Transportation

  Eisenhower State Office Building
  700 SW Harrison Street
  Topeka, KS  United States  66603-3754
• Performing Organizations:

  Kansas State University Transportation Center

  Kansas State University
  Department of Civil Engineering
  Manhattan, KS  United States  66506
• Principal Investigators:

  Jones, Christopher

• Start Date: 20220715
• Expected Completion Date: 20240715
• Actual Completion Date: 0

Subject/Index Terms

• TRT Terms: Durability; Paving materials; Portland cement; Pozzolan; State departments of transportation
• Geographic Terms: Kansas
• Subject Areas: Design; Highways; Materials; Pavements;

Filing Info

• Accession Number: 01858604
• Record Type: Research project
• Source Agency: Kansas Department of Transportation
• Contract Numbers: KSU-23-6, RE-0863-01, C2208
• Files: RIP, STATEDOT
• Created Date: Sep 22 2022 11:36AM