REDUCTION OF SULFATE SWELL IN EXPANSIVE CLAY SUBGRADES IN THE DALLAS DISTRICT. INTERIM REPORT
The addition of hydrated lime to clay soils is one of the most common methods of soil stabilization. However, when sulfates are present in the soil, the calcium in the lime reacts with the sulfates to form ettringite, an expandable mineral. This expansion causes a considerable amount of economical as well as structural problems. Sulfate related heave has been experienced along IH 45 and FM 1382. In this research, a field test method was developed to locate sulfate bearing soils. A permittivity probe was used to measure the electrical conductivity of the in situ soil. The electrical conductivity was then related to sulfate content in soils. Expansion tests were performed to determine the amount of expansion that occurs when lime is added to soils with different sulfate contents. A model that relates the amount of expansion of clay soils to electrical conductivity was proposed. The use of low calcium fly-ashes was investigated and proposed as an alternative form of stabilizer for sulfate bearing soils.
- Research study title: Highway Planning and Operation for District 18 Phase III. Published November 1994; revised May 1995.
Arlington, TX United States 76011
Austin, TX United States 78763-5051
- Bredenkamp, S
- Lytton, R L
- Publication Date: 1995-5
- Features: Appendices; Figures; Photos; References; Tables;
- Pagination: 124 p.
- TRT Terms: Calcium hydroxide; Electrical conductivity; Ettringite; Expansion; Expansive clays; Field tests; Fly ash; Location; Soil stabilization; Subgrade (Pavements); Sulfates; Test procedures
- Uncontrolled Terms: Heaving; Sulfate content
- Old TRIS Terms: Heave; Sulfate bearing soils
- Subject Areas: Geotechnology; Highways; I42: Soil Mechanics;
- Accession Number: 00720288
- Record Type: Publication
- Report/Paper Numbers: TX-95/1994-5, Res Rept 1994-5, TTI: 7-1994
- Contract Numbers: Study 7-1994, Task 16
- Files: TRIS, STATEDOT
- Created Date: Apr 25 1996 12:00AM