Beneficial Reuse of Landfilled Fly Ash in Transportation Infrastructure

This research explores the influence of thermo-mechanical beneficiation methods on the physicochemical characteristics and reactivity of fly ashes disposed of in landfills (LFAs) obtained from power plants in Wyoming and Colorado, USA. An in-depth assessment was conducted on the mechanical and performance aspects of mortar samples incorporating these LFAs, including reactivity, compressive strength, electrical resistivity, resistance to alkali-silica reaction-induced expansion, water absorption, and chloride permeation. The findings indicate that the beneficiation processes effectively enhanced the properties of the substandard ashes, ensuring that all beneficiated ashes met the rigorous standards set by ASTM C618. Thermo-mechanical beneficiation notably improved the physicochemical properties of LFAs, resulting in a reduction in loss on ignition (LOI) and an increase in fineness. The results demonstrated enhancements in the strength activity index of all LFAs post-beneficiation, surpassing the minimum requirement of 75% at 28 days. Furthermore, beneficiation increased heat release and calcium hydroxide consumption, indicating improved pozzolanic reactivity. In most instances, the mortar samples exhibited comparable or superior mechanical and durability performance compared with ASTM C618-compliant fly ash. These findings underscore the potential of beneficiated and reclaimed LFAs as practical alternatives in concrete production, particularly in light of the expected shortage of fly ash in the U.S. and globally.

• Record URL:
  • https://www.ugpti.org/resources/reports/details.php?id=1171
• Record URL:
  • https://rosap.ntl.bts.gov/view/dot/76669
• Summary URL:
  • https://rosap.ntl.bts.gov/view/dot/76951
• Supplemental Notes:
  • This document was sponsored by the U.S. Department of Transportation, University Transportation Centers Program.
• Corporate Authors:

  Colorado State University, Fort Collins

  Fort Collins, CO  United States  80523

  Mountain-Plains Consortium

  North Dakota State University
  Fargo, ND  United States  58108

  Office of the Assistant Secretary for Research and Technology

  University Transportation Centers Program
  Department of Transportation
  Washington, DC  United States  20590
• Authors:
  • Shakouri, Mahmoud
  • Zhang, Chengyi
  • Ksaibati, Khaled
• Publication Date: 2024-5

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Figures; Maps; Photos; References; Tables;
• Pagination: 66p

Subject/Index Terms

• TRT Terms: Admixtures; Beneficiation; Compressive strength; Durability; Electrical resistivity; Fly ash; Physicochemical properties; Recycled materials
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 01927485
• Record Type: Publication
• Report/Paper Numbers: MPC-683
• Contract Numbers: MPC 24-522
• Files: UTC, NTL, TRIS, USDOT
• Created Date: Aug 18 2024 11:28AM