The growth of the construction industry has led to an exponential increase in waste generation. The waste generated by the construction industry is generally called construction and demolition waste or CD waste. Most of the waste from the construction industry is non-biodegradable inert material. Construction waste has the characteristics of heavy weight, high density and large volume, which requires more storage space and cannot be handled according to standard waste disposal methods. "Reduce - Reuse - Recycle" is the most commonly used waste management principle in the construction industry (and any other waste management sector). Management and Sorting of Construction and Demolition Waste.

The supply and demand gap of construction materials such as fine aggregate and coarse aggregate is widening in the construction field, especially in road construction. China's construction industry generates an average of hundreds of millions of tons of waste every year. By recycling aggregates, we can fill the gap between supply and demand and reduce production costs at the same time.

Goals of Construction and Demolition Waste Management

The waste management system should always adhere to the principle of "reduce, reuse, recycle". The waste management strategy should be formulated from the project planning stage itself. The main goals of waste management are: to reduce the amount of waste that is going to landfills or unwanted material disposal sites and to create useful resources from them.

Reduce

Choose materials wisely and do not procure excess or unnecessary materials for the construction project. Excess materials later become waste and also increase the overall cost. It also increases the cost of waste disposal. In the transportation industry, the amount of cut and fill required needs to be carefully planned to avoid over-excavation. This will avoid the original material from going to landfill.

Reuse

Good quality and undamaged materials can be reused for other construction purposes. Therefore, identify these materials and make use of them. Sometimes excess excavation is shared among other projects nearby if there is a fill requirement. Nonetheless, this will require constant communication and upfront planning among stakeholders.

Recycling

By recycling construction waste, different useful construction materials can be produced. For example, in road resurfacing projects, the asphalt layer is carefully scrapped and sent for recycling. The risk of waste disposal can be greatly reduced by recycling waste materials.

Based on the nature of waste generated, construction waste can be classified into the following four major categories.

1. Reusable Materials

Waste materials are reused based on the following criteria, such as quality, size, and amount of contamination. Bricks, wood, roof tiles, glass, etc. are possible materials that can be reused. In addition, these materials can be sold outside and can generate a source of income. The main advantage of this method is that we can save resources.

2. Recyclable materials

Most waste materials are recyclable and can make other useful products. Some recyclable materials include concrete, metal, plastic, wood, glass, etc. A major disadvantage of these fine aggregate products is that it consumes more water than traditional fine aggregate. Metal (including rebar), plastic (PVC), glass can be recycled by melting.

The waste management system mainly focuses on the recycling principle. Recycled aggregate can even be used in road construction. For example, when demolishing an apartment, concrete fragments can be crushed into 6mm~12mm sized aggregates by a crusher.

3. Useless waste

Every construction site retains a certain amount of useless waste. Sometimes, demolition debris is also classified as unwanted waste. These wastes are usually used for landfill.

4. Hazardous waste

Contaminated water and waste, fluorescent lamps, oil, solvents, materials, asbestos materials, PFAS, etc. are hazardous wastes and cannot be handled in the usual way. These types of wastes should be handled in accordance with environmental laws and regulations.

Back to current list