Recycling of construction materials
The green trend conquers all sectors and the world of construction is not far behind. Sustainability is an insurmountable wall that must be respected when making plans for buildings. In fact, more and more initiatives are being carried out in the field of construction to improve the protection of the environment and the reuse of resources.
Technological advances in the field of construction and the environment allow that upon the ending of a project of a building or its demolition, the leftover materials, according to their properties and characteristics, can be reused in a new project. In general, most of the construction and demolition waste (RCD) is destined to the production of aggregates, with which concrete is later manufactured. However, these can be of different nature and be exploited in many ways.
Methods and reusable materials
Not all materials can be reused or subjected to the same processes to give them a new functionality. Below, we show you a list of those leftsover materials that you can recover after a demolition or construction process. Regardless of the material recovered and the procedure to which it has to be submitted for reuse, it is necessary to ensure the quality of the waste that will be recycled. Thus, it has to be guaranteed that the new material complies with the conditions and requirements for a new construction.
- Asphalt: the remains generated by the paving processes are usually processed to be used in the construction of new roads. If they are mixed with other materials, such as asphalt binder, the result is a new paving material.
- Concrete: its leftover products are mostly used as the basis for road construction and as one of the components in the production of new concrete.
- Wood: even wood contaminated with paint can be recovered for another use. The remains of structures, formwork and conglomerates of wood are crushed and classified to produce fuel or as decoration in landscaping.
- Metals: doors, plates, window frames and pipes are some of the metals that can be given a second use. Iron and steel are metals that, in order to be used, have to be melted. If entire pieces are recovered, the sale to scrap merchants is also an option.
- Plastic and glass: finding this waste after demolition is rare. The reuse of these materials is possible thanks to the recycling industry, where are sent prior to the selection and classification procedure.
Classification of materials
Each of the resources used in building, after undergoing a review process, are cataloged according to the secondary use they may have. In this way, they can be classified into three subgroups:
- Reusable materials: usually they are pieces of steel, wood, brick, block, tiles or masonry that have been recovered in good condition. The aggregate materials can be reused as filling material in the new building, or to pave temporary roads that connect the construction with other access roads.
- Recyclable materials: most metals, plastic and glass can be used in the recycling market. In this case, the waste is treated to be reused and to shape new materials or products with similar properties.
- Materials destined to the manufacture of secondary products: the remaining materials that come from rock; ceramics; and concrete; these can be recovered to make secondary products. Metals, plastic and glass can also be recycled for this purpose.
The reduction of air pollution and the exploitation of natural resources are two of the most important in the commitment to sustainability. Using construction and demolition waste in new projects has a series of positive considerations for the environment, such as:
- Impacts associated with the transport of materials: moving what is necessary for the construction of a building has consequences for the environment, especially in the pollution of the air by the particles and gases that the materials give off. In this sense, the recovery of waste reduces the volume of remains that have to be transferred to landfills and the materials with which the new construction will be made.
- Impacts associated with the manufacture of new materials: reusing waste has a positive impact on the saving of consumption of new materials as well as on their manufacture. This also has implications for the preservation of natural spaces since it would reduce the exploitation of mineral resources.
It is important to note that the reuse of construction and demolition waste can also lead to negative consequences, such as the production of noise and dust. In turn, it could have implications for employees and factories producing virgin materials.
However, this issue remains to be one of the most responsible actions with the environment that can be promoted from the construction sector. In any of the cases, the projects of reuse of materials must be accompanied by work plans and cleaning measures. Thus, the environmental impact is minimized to the maximum.