When you’re working with jaw crushers at a construction or mining site, you’ll mostly end up with crushed construction and demolition waste. This material mainly consists of clean concrete and other building waste materials. Considering that this material has a low dust particle content, you can unlock the unused potential by recycling this material. The resulting material that you’ll get is called recycled concrete aggregate.
What is Recycled Concrete Aggregate (RCA)?
Recycled concrete aggregate refers to the material produced from crushed construction and demolition waste. The RCA production process involves breaking and crushing the leftover concrete along with a smaller percentage of the building’s waste material.
Recycled Aggregate Characteristics
Interestingly, recycled aggregates have very different characteristics than those from crushing natural aggregates. The presence of construction waste in the material significantly impacts the recycled concrete aggregate properties.
RCA is less dense as compared to natural aggregates. This is because of the porous nature of the material. Due to this characteristic, RCA has a lower strength and a higher crushing value.
Due to the lower density and highly porous structure, recycled concrete aggregate has a greater water absorption capacity than natural aggregates.
Considering that contaminants such as construction waste and dust particles are present in the recycled concrete aggregate, it is not as strong as the natural aggregates. These contaminants are mostly in the form of building material waste and dust particles.
Size of Aggregate
The size of the aggregate mainly depends on the crushing method that was used in the production. A finer aggregate decreases the concrete compressive strength.
Recycled concrete aggregate has 30% to 60% higher creep than natural aggregate. This is again because of the contaminants that are present in the material.
Recycled concrete aggregate is much more permeable as compared to concrete made with natural aggregate. This, in turn, increases water absorption, thus reducing the durability of concrete.
The percentage of drying shrinkage is much higher because of the internal curing effect. This factor restricts the development and application of recycled concrete aggregate.
Modulus of elasticity
The modulus of elasticity of concrete that is made with recycled concrete aggregate mainly depends on the coarseness of the aggregate. In case the concrete is made with finer aggregate, the modulus of elasticity will be lower. On the other hand, the rate will be higher if it’s made with recycled coarse aggregate.
What kinds of projects can be done with Recycled Concrete?
Following is a list of some projects that can be done with recycled concrete:
- Road construction
- Noise barriers
- Bank protection
- General bulk fills
Advantages of Recycled Concrete Aggregate
Recycled concrete aggregate can help promote natural coarse aggregates (NCA) environmental preservation. Using RCA in construction can be a potential solution to the problems caused by concrete waste. It is mainly used in existing green building composites.
Disadvantages of Recycled Concrete Aggregate
Considering that there are impurities in the contents of recycled concrete aggregate, the quality and workability of concrete are downgraded. The end product is less durable and has lesser compressive strength.
If you’re interested in the heavy equipment involved in producing recycled concrete aggregate, click here.