Recycled concrete

Recycled Concrete | Methods of Recycling Concrete | Uses | Benefits

What is Recycled Concrete?

Recycled concrete is the concrete produced from the method of reusing the concrete, obtained from the demolition and renovation of the old buildings and infrastructure. It is gaining a lot of popularity due to its efficiency and effectiveness. Apart from this, it has a lot of other benefits which has made it a very attractive option for environment friendly building construction.

The second most commonly used material on our planet is concrete. Concrete, a mixture of cement, water and gravel has been the foundation on which the buildings and infrastructure have been built over thousands of years. Also at the same time concrete industry is the second largest producer of the CO2 and is responsible for emitting up to 5% of global CO2 emissions. The amount of CO2 emitted due to concrete production is way more than that produced by all the logistics.

Recycled concrete
Recycled concrete (Source: YouTube/ERC-TECH EU)

Methods of Recycling Concrete

The equipment used for crushing the concrete rubble generally consists of a rubble crusher, side discharge conveyor, screening plant and a return conveyor from the screen to the crusher inlet. The return conveyor sends back the oversized materials or the other under crushed materials which needs reprocessing. The rubble must be free of all the unwanted materials such as plastic, wood, paper and other trash materials. Metals are permissible, since they can be removed by magnets or other sorting devices. These metals later can be recycled by meting it down and used for other purposes. The other aggregates present in the demolition waste can further be recycled by subjecting it to crushing. The crushing is achieved by using the crusher equipment

 

Once the crushing is done, the finely crushed cement can be used for construction purposes whereas the other materials are sorted out through various methods such as hand picking or water floatation. They can either be used as they are or can be subjected to reprocessing. By carrying out the crushing process on the construction site, the transportation cost can be reduced greatly.

 

Equipment used to produce Recycled Concrete
Equipment used to produce Recycled Concrete (Source: YouTube/DW News)

Circular Production Chain for concrete

Until recently, a circular production chain was not possible for concrete. Concrete could not be reused to produce new concrete, at least not in an environment friendly manner. Traditionally, large pieces of concrete is reduced to smaller pieces called rubble granules. These rubble granules are mainly used as a foundation material for roads. Smart crusher has developed a technique for recovering the sand, gravel and the cement from concrete. This unique technique has been tested and proven on a laboratory scale and in practice. 

Traditional concrete crushers are huge. A traditional concrete crusher breaks right through the sand and gravel. Smart crusher on the other hand, crushes only the cement stone leaving the sand and gravel undamaged. The smart crusher not only makes the concrete chain circular, it also makes the sand and gravel better than new. The most important aspect however, is that all the cement can be retrieved clean and unpolluted by fine broken sand. This is a very positive development in the construction field since it uses lesser electric power and economical at the same time.

Smart crusher equipment
Smart crusher equipment (Source: YouTube/SmartCrusher)

Uses of Recycled concrete

  • Finer pieces of recycled concrete can be used as gravel for new construction projects. Sub-base gravel is laid down as the lowest layer in the road with fresh concrete or asphalt poured over it. 
  • Recycled concrete can be used as an efficient building material, if it is crushed properly and kept free of unwanted materials and contaminants. 
  • A process called Rubberization can be achieved through recycled concrete. In this process, the pavement concrete can be broken down in its own place and used as a base layer for the new pavement. 
  • Larger pieces of crushed recycled concrete can be used for Riprap revetments, which are a very effective and popular method of controlling erosion.
  • It is very simple to make new cement from cement stone obtained from the crushers.
  • Wired cages can be filled with crushed concrete and stacked together to provide economical retaining walls

Benefits of Reused concrete

Firstly, the waste produced during construction can be reduced immensely by controlling the wastage of raw materials used in the manufacturing process of concrete. The CO2 emission can be controlled to a great extent by using the smart crushers to crush the recycled concrete. The recovered concrete is economic and environment friendly. The transportation cost can also be reduced by carrying out the recycling process in the same site where the demolition took place.