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How are cement and concrete used in roads and road bases?

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Cement The cement-making process, from crushing and grinding of raw materials, through roasting of the ground and mixed ingredients, to final cooling and storing of the finished product.

Cement and concrete are distinct materials used in road construction, with cement serving as a key ingredient in concrete.1

Concrete in Road Pavements

Concrete is used to create "rigid" pavements. These are constructed using portland cement concrete slabs, typically 6 to 14 inches thick. Because concrete shrinks as it hardens, engineers often incorporate steel reinforcement to enhance tensile strength and control cracking. These slabs are often laid on a supporting layer to prevent traffic pressure from pumping water or soil to the surface through joints.2

Cement in Road Bases

Cement is also used to improve the structural integrity of road foundations. When local soil is substandard for use as a base course, it can be "stabilized" by mixing it with small quantities of portland cement. This process increases the strength and stiffness of the soil while reducing its permeability and susceptibility to water damage. Special machinery is used to distribute the cement into the upper 8 to 20 inches of the soil.32