Placement Water Content
The water content which is used in the field during the compaction of the soil is known as placement water content. This water content, in some places, could be different from the field.
The water content which is used in the field during the compaction of the soil is known as placement water content. This water content, in some places, could be different from the field.
- For light compaction - OMC of Standard Proctor Test
- For heavy compaction - OMC of Moderate Proctor Test
- Pneumatic Rubber Tyre Roller - OMC of Standard Proctor Test
- For Sheet Foot Roller and Smooth Wheel Roller - OMC of Modified Proctor Test
- For the cohesive soil, water content used will be on the wet side of OMC.
- For the earthen dam, water content about 1% to 2.5% less than OMC is used to reduce the pore water pressure.
Effect of Compaction on Engineering Properties of Soil
- Soil Structure - more flocculated or random on dry side, dispersed on wet side
- Strength - more on the dry side
- Swelling - soil swells more on the dry side of OMC
- Shrinkage - soil shrinks more on the wet side of OMC
- Compressibility - less compressible on dry side of OMC
- Permeability - permeability goes on decreasing with increase in water content on dry side
- Pore Water Pressure - more on wet side of OMC
Range of OMC
Sand - 6 to 10%
Sandy Silt / Silty Sand - 8 to 12%
Silt - 12 to 16 %
Clay - 14 to 16%
Sand - 6 to 10%
Sandy Silt / Silty Sand - 8 to 12%
Silt - 12 to 16 %
Clay - 14 to 16%