The Influence of Processing Soil With a Coffee Grinder on Soil Classification
Abstract
Use of a coffee grinder to break up clods of soils is one of the recommended practices of the Rapid Soils Analysis Kit (RSAK). This leads to the question that it may produce fines by cutting/breaking larger particles-potentially leading to the mis-classification of soil. In order to investigate this hypothesis, we performed a laboratory investigation to determine if the use of a coffee grinder produces fines from sand-size particles and whether the production of more finescan result in a different uses classification by some combination of adding soil fines and changing the Atterberg Limits of the fines tested. Three soils were tested--Ottawa Sand (SP), a poorly graded sand with silt (SP-SM) and a sandy lean clay (CL). Processing the soils for 90 seconds in a coffee grinder produced from 15.9% to 18.5% fines from the Ottawa Sand and established that the coffee grinder breaks down sand particles into fines. For the coarse Elevator Soil, originally an SP-SM, the fines production changed the soil classification to SM, while the Liquid Limit decreased from a measureable 21 to non-plastic, and Plastic Limit decreased from 19 to 17. For the Harte Clay (CL), the soil classification did not change; but the Liquid Limitand Plastic Limit both significantly increased. Therefore, for both the production of fines and the resulting impact on Atterberg Limits, the influence of using a coffee grinder to process soil cannot be quantified without further, systematic study.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 20, 2015
- Accession Number
- AD1013452
Entities
People
- Benjamin Fonte
- Heidi Hunter
- Karen S. Henry
Organizations
- United States Air Force Academy