Compaction

To achieve effective, long lasting compaction the soil should be slightly wet when being compacted. The water in the soil acts as a lubricant allowing the soil particles to slide against each other and move very tight together. Very dry soil doesn't compact very well as the particles do not bond to each other as they slide. Very wet soil doesn't compact very well either - the water fills the little gaps or voids in the soil and isn't able to be pressed out during compaction.

It takes the correct amount of water in the soil to achieve the highest amount of compaction. The amount of water varies depending on the soil type and location, and can be determined by performing tests on the soil.

POINTS TO REMEMBER:

• soil too dry - doesn't compact well
• soil too wet - doesn't compact well
• soil just wet enough - compacts well