The Untold Story of Crushed Aggregate

Crushed, or rock, aggregate is a product often produced for a variety of residential purposes, such as landscaping, pathways, drainage, and the base under concrete or pavers. Most of the time, these aggregates aren’t given much thought, but the work that goes into the preparation of the rocks and the actual aggregate crushing is significant.

The Components of the Aggregate

The first part of the process involves choosing the components; some of the most common materials include crushed rock, gravel, sand, and stones of many varieties. Naturally, the materials used in each mixture are affected by the intended use of the aggregate. The mix used in building foundations is much different in makeup and appearance from the mix used for park pathways. Additionally, there’s a lot of variety in the size of stones and other materials used to form the aggregate.

The Preparation and Production of the Aggregate

Once the makeup of the aggregate has been determined, the next step in aggregate crushing is a progression through several pieces of heavy equipment. Each piece of machinery plays an essential role in preparing the stones.

• Vibrating conveyer belts separate large pieces of stone from smaller pieces.
• Jaw crushers quickly break down large pieces of rock, compressing each into smaller and smaller pieces by forcing the chunks between angled and vertical plates.
• An impact crusher breaks those chunks of rock into much smaller pieces. This crusher uses a wheel system where rocks are thrown against a stationary hard plate.
• A vibrating screen further filters the new fragments of stone into a variety of sizes.

The crushed stones are sorted by size and labeled according to a number system, the higher the number, the smaller the size of the stone. After the stones are prepared, other materials may be added, such as topsoil, mulch, or salt.

The Transportation of the Final Product

After the final aggregate crushing and sorting, dump trucks are used to transport the final product to earthwork retailers, consumers, or the intended worksite. These useful rock mixtures are commonly used in construction in spite of not being noticed when the final touches have been completed.