A group of rocks is known as an aggregate. While it sounds very simple and unimportant, people and vehicles depend upon aggregates for their transportation needs. These small rocks come in a variety of sizes and materials that have been mined. The majority of them are used to form a foundation or bed for roads being built. Without them, roads would sag and crumble due to weather as well as wear and tear.

Roads are built from the ground up. The road bed must be prepared and layers of support are added. These support layers consist of aggregates such as gravel, small stones, ground stone or sand. Each layer provides a base for the layer above. In this manner, the road surface is supported as vehicles go over it. These layers are also a foundation that helps contain and control rain water to keep the road surface as safe as possible.


The Expanding Need for Good Roads

Civilization has continually expanded over the last 2 millennia. Mankind is always on the move for resources as well as...


Creating a Road Bed

Every road built to stand up to traffic needs a well-laid road bed. The purpose of this bed is to...


Common Road Surfaces

Dirt, concrete and asphalt are all common road surfaces. The type of surface chosen depends on a number of factors....