Use a Tamper Rammer for Compaction of Soil (Subgrade)
From the Ground up Compation is Important and a Tamping Rammer does it well
Tamping or compaction of soil, or whatever makes up the natural ground is the first stage to ensure good results. (In official terms this is called Compaction of Subgrade). When the access or the overall area is limited a Tamper Rammer is the obvious machine to use, if it’s a larger area then a vibrating plate compactor or vibrating roller will be more efficient.
The amount of compaction needed at this stage depends on a number of factors including, how much it has been disturbed during excavations, the composition of the ground and the moisture content. A few passes, 4 -8, with a rammer should be enough to consolidate this lowest level. The actual number of passes is normally determined by the operator noticing that the ground isn’t compacting any more, he may notice the machine feels different as the ground doesn’t absorb as much energy and the machine starts to bounce or hop a bit.
If soil or excavated material is being used for backfilling it should be done in layers. This will ensure the compaction of all the material. It’s no good filling in a deep hole and expecting the tamper rammer to compact right to bottom. The layers are called “lifts”, the depth of each lift is dependent on the material. Sand and granular soils can be layered in 200mm lifts whilst cohesive soils (with a lot of clay content) or stony soil should be in a maximum of 150mm lifts. In both cases the layers should be a minimum of 100mm and not be too dry or too wet. The deeper lifts will require more passes with the tamper rammer so it’s worth considering the time spent on compaction compared to the time spent moving material.
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Compact Sub-Grade (Soil) with a Tamper Rammer
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