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How to make a good mix for road base course for good compaction
in Highway Design & Maintenance by  

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How to make a good Mix for Road Base

Compaction is the process of densifying, or reducing the volume of, a mass of material.
For asphalt mixtures, compaction locks the asphalt-coated aggregate particles together to achieve stability and provide resistance to deformation (or rutting) while simultaneously reducing the permeability of the mixture and improving its durability.
There are many factors that affect the compactability of asphalt mixtures. Among those factors are the properties of the asphalt mixture, the type and density of the underlying base course material, the thickness of the asphalt layers, and the environmental conditions at the time of placement. If any of these factors change, the final modulus, stiffness or strength of the mix will be directly affected. Additionally, the final compactability of the mix is affected by the type of rollers, the number of rollers, and the rolling patterns used during the compaction process.
Mix Temperature
It has been said that the three most important factors that affect the ability of a contractor to achieve the desired level of density in an asphalt mix are, in order of importance, temperature, temperature and temperature.
The temperature at which an asphalt mix is produced affects both the ease of compaction and the time available for compaction. The time available for compaction increases with mix temperature,