- 2078 Baisakh · 2 marks
Field tests for sand and clay
Short answer
Sandy soil: gritty, crumbles easily, quick dilatancy, settles fast, no thread. Clayey soil: high dry strength, slow/no dilatancy, rolls into 3 mm tough thread, sticky and shiny, stays suspended.
Name the tests generally done to identify sandy soil and clayey soil in the field.
Sandy soil
- Visual and touch: coarse, gritty, grains visible to the naked eye.
- Dry strength test: crumbles easily; no strength.
- Dilatancy test: quick reaction with water rising to the surface (for fine sand).
- Sedimentation test: settles in less than a minute.
- Does not form a thread (no plasticity).
Clayey soil
- Dry strength test: high strength; hard to crush.
- Dilatancy test: no or very slow reaction.
- Toughness (thread) test: rolls into 3 mm thread; tough and cohesive.
- Stickiness/shine test: sticky, smooth, with shiny cut surface.
- Sedimentation test: stays in suspension for a long time.
✓ Answer checked by Claude Opus 5.5 (high effort)
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