In recent years, China’s annual construction waste generated by new construction projects can reach 100 million tons, and the construction waste generated by building demolition can reach 200 million tons. With the development of China’s urbanization, the figure is still rising，
Therefore, the resource utilization of construction waste is not only particularly necessary, but also has the scientific feasibility of implementation. At the same time, China shall innovate the resource utilization technology of construction waste, so as to effectively improve the recycling rate of construction waste. These measures are of great practical significance to the construction of modern urban ecological civilization.
Advantages of construction waste resource utilization:
Effectively alleviate resource shortage
China’s mineral resources reserves are insufficient, coupled with the wanton exploitation of resources in recent years and the lack of attention to the recycling of resources, resulting in a lack of resources and an obvious shortage of supply. Some important resources need to rely on imports more and more. The multi-level recycling of construction waste can effectively alleviate this resource crisis and realize the sustainable development of economy.
Effectively reduce environmental pollution
The temporary storage and landfill of construction waste will seriously pollute the shallow surface, rivers and groundwater resources; If construction waste can be recycled, it will effectively reduce environmental pollution and improve environmental quality.
Significantly improve its economic benefits
In recent years, China’s effort on urban construction and transformation efforts are unprecedented, ushering in an unprecedented construction climax, followed by a large number of construction waste. With the rapid development of economy, building materials resources are becoming increasingly scarce. If construction waste can be recycled, the problem of resource shortage will be alleviated to a great extent, enterprise costs will be reduced. And the sustainable development of resources will be achieved.
Current construction waste resource utilization technology:
Waste reinforcement bas treatment method
The ideal utilization method of reinforcement is to use it directly or melt it into new reinforcement for reuse. Some waste steel bars that are difficult to meet the construction needs of construction projects and can no longer be used can be melted into new steel and then put into use again. Relevant survey results show that at present, China has many large-scale waste steel recycling markets, and the recycling rate of waste steel is high.
The treatment of waste concrete is mainly classified utilization.
1- The most elementary use is to crush and screen waste concrete, and the treated concrete can be used for landfilling of the foundation of construction projects and the bottom layer of highway construction. For a long time, landfill has been used to treat and utilize waste concrete, but this method does not maximize the use of waste concrete.
2- The second level of utilization is the production of construction waste bricks. The crushed waste concrete is first screened, then washed, dried, etc. After treatment, natural sand, Portland cement and other additives are added to make recycled bricks that can be re-used in construction projects;
3- The most advanced utilization is the production of recycled concrete. The recycled fine and coarse aggregates made from waste concrete after the secondary treatment can be used as substitutes for natural fine aggregates and coarse aggregates, helping to reduce construction waste emissions. In turn, the resource utilization rate of construction waste is improved.
Improvement measures for the utilization of construction waste:
Stick to reduce and resue
Currently, most Chinese construction engineering designs lack effective attention to issues such as the prevention, reduction and reutilization of construction waste. For developed countries, research on reduction and recycling technologies from the root has been developed very mature. For example, the Royal Institute of British Architects clearly pointed out that the ideal time to reduce construction waste is at the beginning of the overall construction process of a building. China should learn from such ideas and study related technologies.
Develop low-cost, high-efficiency processing technology
The most important thing for studying low-cost treatment technology is to improve the classification technology and equipment of construction waste, and solve the problem of classification at the construction site of construction projects. At present, due to their limited capabilities, some companies usually carry out classification on their own, which is obviously not the most ideal method because this is far less efficient and effective than source classification, and it will also generate higher processing costs. Besides, Research on low-cost processing technology should be effectively combined with recycled products. Recycled products with large applications can reduce costs. It should also be effectively combined with on-site recycling to reduce flip-chip and transportation costs.
The utilization of construction waste as a resource is a complex systematic project involving many different links, such as production, classification, transportation, treatment, etc., requiring close cooperation from all parties. Therefore, personnel from all parties must continue to study and summarize experience, comprehensively analyze the main problems in the utilization of construction waste at this stage, strengthen the development of reduction and recycling technologies, develop low-cost and high-efficiency treatment technologies, and actively promote Effectively improve the utilization rate of construction waste resources.