Construction Jobs: How Aggregates Are Sourced

“Aggregates are raw materials that are produced from natural sources and extracted from pits and quarries, including gravel, crushed stone, and sand. When used with a binding medium, like water, cement, and asphalt, they are used to form compound materials, such as asphalt concrete and Portland cement concrete,” says AEM. At Kilgore Companies, we pride ourselves on our comprehensive understanding of how crucial high-quality aggregates are to the construction industry. Aggregates form the foundation of many construction projects, including roads, bridges, and buildings. Understanding the sourcing process of aggregates is essential for ensuring we deliver the best materials for our clients’ construction jobs.

Understanding Aggregates

Aggregates are granular materials used in construction, including sand, gravel, crushed stone, and recycled concrete. These materials are critical components of composite materials like concrete and asphalt, providing strength and durability. The quality and properties of the aggregates significantly influence the overall quality of the construction project.

Identifying Aggregate Sources

The first step in sourcing aggregates is identifying suitable locations. Geologists and surveyors play a crucial role in this process. They conduct surveys to locate deposits of sand, gravel, and rock. This involves analyzing the geological formations and using various methods, such as aerial photography, geological maps, and on-site inspections.

Once potential sites are identified, samples are collected and tested for quality. The testing process evaluates various factors, including particle size distribution, shape, and texture. These characteristics determine the suitability of the aggregates for different types of construction jobs.

Extraction Process

After identifying a suitable source, the next step is extraction. The extraction method depends on the type of aggregate and its location. Here are the common methods used:


“Quarrying is the process of removing rock, sand, gravel, or other minerals from the ground to use them to produce materials for construction or other uses. So, a quarry is any such work on the surface of the earth where minerals are extracted. Quarries are also known by other names around the world: ‘surface mine’, ‘pit’, ‘open pit’ or ‘opencast mine’,” says the Institute of Quarrying. Quarrying is the most common method for extracting hard rock aggregates like granite, limestone, and sandstone. The process involves removing large blocks of stone from the earth. We use heavy machinery, such as excavators and bulldozers, to break up the rock and transport it to processing plants.


For aggregates like sand and gravel, mining is often the preferred method. This involves excavating the material from riverbeds, floodplains, and other natural deposits. Mining can be done using open-pit techniques or dredging, depending on the location and depth of the deposit.


Recycling is an increasingly important source of aggregates, especially in urban areas where space for new quarries is limited. Recycled aggregates are produced by crushing and processing old concrete and asphalt from demolition sites. This not only provides a sustainable source of aggregates but also reduces waste and the environmental impact of construction jobs.

Processing Aggregates

Once the aggregates are extracted, they need to be processed to meet specific requirements. Processing involves crushing, screening, and washing the material to achieve the desired size and quality.


Crushing is the first step in the processing of aggregates. Large rocks are broken down into smaller pieces using crushers. The type of crusher used depends on the hardness and size of the material. Jaw crushers, cone crushers, and impact crushers are commonly used in this stage.


After crushing, the material is screened to separate different sizes. Screening involves passing the aggregates through various sieves to obtain uniform sizes required for specific construction jobs. This step ensures that the aggregates meet the specifications for strength and durability.


Washing is an essential part of the processing stage, especially for sand and gravel. It removes impurities like clay, silt, and dust from the aggregates. Clean aggregates are vital for high-quality concrete and asphalt, ensuring the longevity and performance of construction projects.

Quality Control and Testing

Quality control is paramount in the sourcing of aggregates. We conduct testing at every stage of the process, from extraction to processing. Our quality control measures include:

Gradation Testing

Gradation testing measures the distribution of particle sizes within the aggregate. This is crucial for ensuring the aggregates provide the right balance of strength and workability in concrete and asphalt.

Moisture Content

Moisture content testing ensures the aggregates have the right amount of moisture for mixing with cement or bitumen. Too much or too little moisture can affect the consistency and strength of the final product.

Strength Testing

Strength testing evaluates the ability of the aggregates to withstand loads without breaking or degrading. This is particularly important for aggregates used in structural applications like bridges and high-rise buildings.

Environmental Considerations

Sourcing aggregates responsibly is a key part of our commitment to sustainable practices. We take several measures to minimize the environmental impact of our operations:

Water Management

Water management is critical in both extraction and processing. We implement systems to recycle water and reduce consumption, protecting local water resources.

Dust and Noise Control

To mitigate dust and noise pollution, we use advanced equipment and techniques. Dust suppression systems and noise barriers help protect the health and well-being of our workers and the surrounding communities.

Transportation and Logistics

The final step in the process is transporting the aggregates to the construction site. Efficient logistics are essential to ensure timely delivery and reduce transportation costs. We use a combination of trucks, trains, and barges, depending on the location and distance to the site.

Proper handling and storage during transportation are vital to maintain the quality of the aggregates. We use covered transport and storage facilities to protect the material from contamination and weathering.

At Kilgore Companies, we understand that high-quality aggregates are the cornerstone of successful construction jobs. From identifying and extracting the right materials to processing and transporting them, every step in the sourcing process is crucial. Our commitment to quality control and environmental responsibility ensures that we provide the best aggregates for our client’s projects, contributing to the durability and sustainability of the built environment. By following these processes, we ensure that our aggregates meet the highest standards, providing a reliable foundation for all construction jobs. Through innovation and sustainable practices, we continue to set the benchmark for quality in the industry, supporting the growth and development of communities across the region. Check out our website to learn more.