A compaction apparatus or compactor is usually a motor driven machine useful for soil compaction into 100 mm or 150 mm diameter moulds. Compaction and penetration test on soil is very essential and every soil laboratory conducts compaction tests nowadays.

Compaction of soil, whenever and wherever laid, is of utmost importance to ensure longevity and strength of the structure built over it throughout the designed life of the structure. Good compaction of soil results in minimising of its settlement on application of load, increases its density thus increasing its shear strength and decreases its permeability leading to a fall in its water absorption and reduction in its swelling or shrinkage.

Features

These apparatus are available as mechanically cum electrically operated automatic types. A typical soil compactor possess the following features :

• Provided with collar, base plate and two sets of rammer. One of the rammers is of 2.6 kg and arranged for 310 mm drop , while the other is 4.9 kg and arranged for 450 mm fall.
• For compaction of soil upto 150 mm dia moulds, 100 mm face dia rammers having weight 2.6 kg and 4.89 kg are used.

Materials used for making Compaction Apparatus

These apparatus are generally made of Gun metal or mild steel.

Working Principle of Apparatus

A soil compaction apparatus works on the following principle :

• The rammer set is provided with a ratchet and pawl arrangement to lift it from the top of the soil layer.
• When the rammer reaches the required height, the pawl release the rammer that falls freely on soil surface.
• The release of rammer is operated by an arm that moves up and down and is connected to a reduction gear coupled to the motor through another arm.
• An automatic blow counter is fitted to the compactor, which is used to set the number of blows.
• The base plate of the mould needs to be attached to the rotating base plate of the apparatus that makes 1/5th revolution per stroke.

Uses

• Helps to save time and eliminates tedious hand compaction process.
• Suitable to use for normal compaction, heavy compaction, etc.
• The equipment is suitable for operation on 230 volts, 50 cycles, single phase, AC supply etc.
• Can be used to conduct moisture density tests using small samples of soil.

Application

Application in different industries as well as in different areas like :

• Construction (Dams, Buildings, etc.)
• Civil Engineering
• Geotechnical Engineering
• Trench Monitoring
• Concrete Sampling
• Agriculture