How to Make Construction Aggregate - Amazing Process with Machine List

Construction aggregate—from 0–5mm sand to 20–31.5mm crushed stone—is the backbone of global infrastructure. Used in concrete, asphalt, road bases, and building foundations, high-quality aggregate must meet strict standards for strength, particle size, and purity. Whether you’re processing natural rock (limestone, granite) or recycled concrete waste, the production process follows a systematic workflow—powered by specialized machinery.

What is Construction Aggregate?

Construction aggregate is a broad category of coarse- to medium-grained particulate material, including sand, gravel, crushed stone, and recycled concrete. It's primarily used as a base material under foundations, roads, and railways, and as a key ingredient in concrete and asphalt. Aggregate is categorized by size:​
● Fine aggregate: 0–5mm (sand, used for mortar, concrete mix).​
● Coarse aggregate: 5–31.5mm (crushed stone/gravel, used for road bases, concrete cores).​
● Recycled aggregate: Processed from demolition waste (concrete, bricks), an eco-friendly alternative to natural aggregate .

The Step-by-Step Process of Making Aggregate

The production of aggregate is a multi-stage process designed to break down large rocks into specific, uniform sizes. Here’s how it works:

Step 1: Quarrying and Extraction
It all starts at the source: a quarry, pit, or mine. Large, powerful machines like drills and excavators are used to break solid bedrock or harvest sand and gravel deposits from pits. Explosives are often used to fracture large rock formations into manageable pieces.

Step 2: Transport to the Processing Plant
The extracted raw material, known as "shot rock," is then loaded onto heavy-duty trucks or conveyor belts and transported to a processing plant, which is often located at or near the quarry site.

Step 3: Primary Crushing (The First Breakdown)
This is where the real transformation begins. The large shot rock (which can be several feet across) is fed into a primary crusher. These massive machines use immense pressure to break the rock down to a size of about 15-20 cm (6-8 inches). Jaw crushers and gyratory crushers are the most common types used in this first stage.

Step 4: Screening and Sorting (The First Sort)
After primary crushing, the material is moved via conveyor to a vibrating screen. This machine separates the crushed rock by size. Pieces that are already the correct size are routed to the final product piles. Larger pieces that need further reduction are sent to the next stage.

Step 5: Secondary and Tertiary Crushing (For Precision)
To achieve specific, smaller aggregate sizes (like those used for asphalt or concrete), the larger pieces undergo further crushing. Secondary crushers​ (like cone crushers) and tertiary crushers​ further break down the rock with more precision. This stage is crucial for creating cubical-shaped particles, which are highly valued for their strength and compaction properties.

Step 6: Final Screening and Washing
The crushed material is screened one final time to separate it into exact product sizes (e.g., ¾”, ½”, 3/8” chips). In some cases, the aggregate is also washed​ in a sand screw or log washer to remove dirt, clay, and other impurities. This is essential for producing high-quality concrete sand.

Step 7: Stockpiling and Storage
The final, sorted aggregates are conveyed to separate stockpiles based on their size. These stockpiles are then ready to be loaded into trucks and shipped to construction sites.

Essential Machine List for Aggregate Production

Here is a comprehensive list of the key machines used in a modern aggregate plant:
● Drills:​ For creating blast holes in bedrock.
● Hydraulic Excavators & Wheel Loaders:​ For digging, loading, and moving material.
● Haul Trucks:​ For transporting raw material from the quarry to the plant.
● Primary Crusher (Jaw Crusher or Gyratory Crusher):​ For the first, coarse reduction of large rock.
● Cone Crusher (Secondary/Tertiary Crusher):​ For further reduction and shaping of the aggregate.
● Vibrating Screen (Scalping Screen, Inclined Screen):​ The workhorse for sorting material by size at various stages.
● Conveyor Belts:​ The arteries of the plant, moving material between crushers, screens, and stockpiles.
● Wheel type Washer / Sand Screw:​ For cleaning and dewatering aggregates to remove contaminants.
● Stockpile Stacker / Radial Stacker:​ For building organized and large stockpiles of different aggregate sizes.

The production of construction aggregate is a perfect example of industrial efficiency. It transforms raw, natural resources into a engineered, standardized product that is fundamental to our world's infrastructure. Contact us to learn how our range of crushers, screens, and washers can optimize your production line for maximum efficiency and profitability.