Use of Soil-Steel Slag-Class-C Fly Ash Mixtures in Subgrade Applications

In this research study, an experimental program was undertaken to investigate the suitability of using mixtures of steel slag and Class-C fly ash and mixtures of steel and blast furnace slags to replace lime in subgrade stabilization applications. Soil-5% steel slag-5% Class-C fly ash, soil-7% steel slag-3% Class-C fly ash, soil-8% steel slag-2% Class-C fly ash and soil-7% steel slag-3% blast furnace slag mixtures were explored as subgrade materials. The clayey subgrade soil collected from the proposed implementation site was characterized prior to stabilization through a series of tests which included, specific gravity, Atterberg limits, grain-size analysis, compaction, California Bearing Ratio (CBR)-swelling and unconfined compression tests. The mechanical properties of the mixtures of soil, steel slag and Class-C fly ash and of the mixtures of soil, steel slag and blast furnace slag were obtained through compaction and unconfined compression tests. In order to assess the swelling potential of the mixtures of soil, steel slag and Class-C fly ash, CBR swelling tests were also performed on the mixtures. Based on the experimental results, the authors suggested the use of a 7% steel slag-3% Class-C fly ash mixture as a stabilizing material. The implementation of the mixture of soil, steel slag and Class-C fly ash selected was carried out in a road construction project at the intersection of 109th Avenue and Interstate-65, near Crown Point, Indiana. The 7% steel slag-3% Class-C fly ash mixture was used to stabilize the in situ subgrade soils of some sections of the I-65 ramps located in the SW and NW quadrants of the intersection of 109th Avenue and I-65. Field compaction quality control was done by performing Dynamic Cone Penetration Tests (DCPTs) and nuclear gauge tests. The subgrade was monitored and checked for possible cracks or signs of distress. Cracks or signs of distress were not observed on the subgrade before the placement of the base course and concrete. The stabilized subgrade performed satisfactorily.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Figures; Photos; References; Tables;
  • Pagination: 87p

Subject/Index Terms

Filing Info

  • Accession Number: 01496731
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/IN/JTRP-2013/06
  • Contract Numbers: SPR-3477
  • Files: TRIS, ATRI, USDOT, STATEDOT
  • Created Date: Oct 15 2013 4:22PM