Emerson Class Assessments
Emerson's class categorises soils according to their shear strength. It is a quick preliminary test for soil classification and can be combined with other specialised testing.
Overview
At Atlas Engineering and Technology Group, we offer comprehensive Emerson Class Assessments as part of our Materials Conformance Testing services.
What is the Emerson Class Test?
The Emerson Class test is a laboratory method used to classify the structural stability of soil aggregates when immersed in water. This classification helps determine:
- The likelihood of soil dispersion or slaking when wet
- Potential erosion issues on construction and development sites
- Soil suitability for reuse or stabilisation treatments
Emerson Class testing is particularly relevant in geotechnical investigations, roadworks, subgrade assessments, and environmental compliance checks.
Benefits of Emerson Class Assessments
- Identifies soil types prone to erosion or dispersion
- Supports informed design of earthworks and drainage
- Minimises the risk of slope failure and sediment runoff
- Assists in selecting appropriate soil treatments or stabilisers
Emerson Class Categories
Soils are classified into eight Emerson Classes, grouped by their reaction to water immersion:
| Class | Description |
|---|---|
| 1 | Disperses completely in water (highly dispersive) |
| 2 | Slakes then disperses (dispersive) |
| 3 | Slakes but does not disperse (non-dispersive) |
| 4 | Stable with moderate cohesion |
| 5 | Stable with strong cohesion |
| 6 | Highly stable aggregates with fine porosity |
| 7 | Very stable aggregates resistant to slaking |
| 8 | Exceptionally stable – no slaking or dispersion |