Evaluation of Biochar as a Soil Improvement Additive to Mid-Atlantic Expansive Clay
Publication: Geo-Congress 2024
ABSTRACT
Unified soil classification system (USCS) identifies a problematic high-liquid-limit clay that contains montmorillonite minerals as fat clay. Fat clay exhibits excessive swelling when wet and shrinkage when dry. Such drastic fluctuation in behavior qualifies fat clay as the most notorious member of the problematic soil group. This study identified wood-based biochar as a potential additive to fat clay to improve its engineering behavior and investigated the changes in the mechanical properties of the resulting mixture. Biochar amount is varied by volume-based percentage, and the compression and strength behavior of the clay-biochar mixture is assessed using laboratory tests. Compaction tests showed that the maximum dry unit weight of fat clay decreased as the percentage of biochar amendment increased. Six percent biochar added to the fat clay increased the optimum moisture content. The optimum moisture content remained unchanged when the volume of biochar rose from 6% to 10%. Unconfined compression tests showed that the shear strength of the fat clay increased at least twofold as the percentage of biochar was increased. Compression tests showed that the compressibility of fat clay decreased as the biochar percentage increased. Overall, the results of this study elucidated biochar’s potential as a novel soil improvement additive.
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Information & Authors
Information
Published In
Geo-Congress 2024
Pages: 442 - 449
History
Published online: Feb 22, 2024
ASCE Technical Topics:
- Ashes
- Clays
- Compression tests
- Engineering fundamentals
- Engineering materials (by type)
- Expansive soils
- Fine-grained soils
- Geomechanics
- Geotechnical engineering
- Laboratory tests
- Materials engineering
- Soil classification
- Soil compression
- Soil dynamics
- Soil mechanics
- Soil properties
- Soil stabilization
- Soils (by type)
- Tests (by type)
Authors
Metrics & Citations
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