Where does happen compaction?

Answer 1

Compaction in the broad civil engineering sense is usually meant to mean the increasing of the density of a material by applying compactive effort and removing the air present, i.e. decreasing air voids content.

Good compaction is not difficult.

You first need a material that is in a suitable condition to be compacted, you lay it in the correct layer thickness, and you use compaction plant capable of compacting that thickness.

A variety of rollers both in size, weight and type are available to compact soil, granular and bituminous materials, and a number of hand operated devices are available for compaction in confined spaces such as trenches and haunch widenings.

By far the most common cause of poor compaction is attempting to compact too thick a layer of material at a time.

It is necessary to have the correct combination of roller compactive effort related to the thickness of material laid for successful compaction to occur.

The importance of the correct compaction of materials cannot be stressed too highly, and you will find reference to appropriate compaction procedures in many British Standards, DOT Specifications and DOT Design Manuals, Specification for the Reinstatement of Openings in the Highway, and other publications.

Soil compaction will depend upon the nature of the soil and its moisture content.

The soil can be a cohesive clay, sand and gravel, or more likely some combination of clay and granular material, e.g. boulder clay, which is what makes soil engineering so interesting.

But if you have a soil, or granular material, that has cohesive properties, (i.e. exhibit plasticity), to whatever degree, moisture content becomes very important.

Too wet you will have consolidation problems at a later date, too dry and full compaction will be hard to achieve, and further compaction/consolidation will happen at a later date as equilibrium moisture content is established.