Modification of an East Tennessee High Plasticity Silt with Lime and Substandard Fly Ash

Substandard fly ash (high carbon/loss-on-ignition (LOI)), as well as undesirable soils such as MH, or calcium hydroxide (CH), soils (silts, or clays, with high plasticity), are materials that are in abundant supply in Tennessee. If these materials can be successfully utilized in engineering applications, they will provide both economic and environmental benefits. Thus, an investigation was conducted into the performance of one MH soil modified with substandard fly ash and hydrated lime in comparison to both an unmodified MH soil and an MH soil modified with only hydrated lime. The optimum moisture content (OMC) and plasticity index (PI) were obtained for the unmodified and lime-substandard fly ash soil mixtures. The California Bearing Ratio (CBR) and unconfined compressive strength were obtained for all three of the soil mixtures at varying moisture contents. A hazardous waste evaluation was also obtained on a specimen of the lime-substandard fly ash soil mixture. The results indicate that a high LOI fly ash can be useful as a modifying agent when used in combination with hydrated lime for treatment of soils with a high plasticity. More specifically, the lime-substandard fly ash modification resulted in a reduction in the PI, an increase in OMC, a significant increase to CBR, and a significant increase to the unconfined compressive strength when compared to the unmodified soil. In addition, the lime-substandard fly ash specimen was determined not hazardous based on the characteristic toxicity.

• 
• Supplemental Notes:
  • Alternate title: Modification of East Tennessee High-Plasticity Silt with Lime and Substandard Fly Ash. This paper was sponsored by TRB committee AFS80 Cementitious Stabilization.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Dillon, Sarah
  • Crouch, L K
  • Browning, Allen
  • Badoe, Daniel
• Conference:
  • Transportation Research Board 94th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2015-1-11 to 2015-1-15
• Date: 2015

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 13p
• Monograph Title: TRB 94th Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Calcium hydroxide; California bearing ratio; Compressive strength; Fly ash; Moisture content; Plasticity index; Silts; Soils
• Geographic Terms: Tennessee
• Subject Areas: Geotechnology; Highways; I42: Soil Mechanics;

Filing Info

• Accession Number: 01551248
• Record Type: Publication
• Report/Paper Numbers: 15-0670
• Files: PRP, TRIS, TRB, ATRI
• Created Date: Jan 27 2015 11:22AM