Construction, demolition, and renovation activities generate hundreds of millions of tons of solid waste globally each year. In the United States alone, approximately 136 million tons of construction-related C&D waste were generated in 1996.
These seemingly useless wastes contain enormous resource potential.
1. Definition and Composition of C&D Waste
C&D waste refers to waste materials generated during the construction, demolition, renovation, and repair of buildings, roads, bridges, and other structures.
These materials are diverse, mainly including concrete, wood, asphalt, gypsum board (primarily composed of gypsum), metals, bricks, and plastics. C&D waste also includes recyclable building components such as doors, windows, and plumbing equipment.
Based on material characteristics, C&D waste is generally divided into two categories: inert materials and non-inert materials. Inert materials include rock, concrete, asphalt, gravel, bricks, stones, and soil; non-inert materials include bamboo, wood, plastics, and packaging materials.
Studies show that the ratio of inert to non-inert materials in C&D waste is approximately 9:1.
2. Complete C&D Waste Recycling Chain
The C&D waste recycling process is a complete system, covering all stages from generation to final resource utilization.
In Baiyun District, construction waste is transported from fixed collection points in residential areas to the Xinshi Street construction waste collection point. Workers perform preliminary sorting, separating high-value, easily sortable recyclable materials such as wood planks and iron blocks.
Currently, cities like Guangzhou have established a complete collection and transportation system. They utilize inefficient land uses such as under-bridge spaces, idle land, and undeveloped construction sites to build temporary construction waste collection points, ensuring at least one collection point on each street.
Simultaneously, mobile intelligent collection boxes are placed in residential areas or temporary parking spaces along roadsides to compensate for the insufficient service capacity of temporary collection points on some streets.
In the disposal stage, construction waste enters a dedicated resource utilization production line. Taking a waste disposal company in Baiyun District as an example, this facility employs a combined process of “multi-stage crushing + multi-stage 3D screening + multi-gradient fine sorting”.
In the final disposal stage, high-purity stones and stone powder can be sold directly and then used to produce materials such as water-stabilized bricks. Lightweight combustibles are sent for incineration power generation.
3. Modern C&D Waste Recycling Equipment
Modern C&D waste recycling equipment integrates multiple advanced technologies, significantly improving resource utilization efficiency and product value.
Intelligent Sorting System
Traditional manual sorting methods are inefficient and costly. Modern equipment introduces AI-intelligent robot sorting technology. These robots can accurately identify construction waste of different materials and classify it into different subcategories, such as wood blocks, hard plastics, and metals.
Multi-stage Crushing and Screening
Construction waste resource recycling technology processes construction waste through crushing, screening, and purification processes. Modern equipment typically uses a two-stage crushing process combined with a multi-stage screening system to efficiently convert construction waste into recycled aggregate.
Dust Control and Environmentally Friendly Design
Advanced recycling equipment prioritizes environmental protection, employing an integrated plant design. Through methods such as closed systems, negative pressure vacuum recovery, and spraying, it achieves three-stage dust treatment: dust reduction, dust suppression, and dust control.
Automated Control System
Modern C&D waste recycling equipment is typically equipped with automated and intelligent control systems. During production, monitoring is only required in the central control room, achieving a dual improvement in efficiency and safety.
4. Economic and Environmental Value of Equipment Operation
Investing in advanced C&D waste recycling equipment not only brings environmental benefits but also creates significant economic value.
From a cost-saving perspective, recycling C&D waste can reduce the procurement costs of new materials and lower waste disposal costs. Construction waste generators pay disposal fees according to the “generator pays” principle, while the operating entity gains revenue through resource utilization.
In terms of environmental benefits, recycling C&D waste can effectively save landfill space and reduce the environmental pressure on the extraction of new raw materials. Data shows that the comprehensive utilization of each ton of construction waste can reduce carbon emissions by approximately 0.698 tons.
In terms of resource output, processed construction waste can produce various recycled products, including recycled aggregate concrete, recycled bricks, and road construction materials. The Guangzhou Environmental Investment Group’s construction waste resource utilization demonstration project can process 1 million tons of construction waste annually, producing 300,000 tons of recycled water-stabilized material and 2.4 million cubic meters of concrete.
5. Industry Trends
The C&D waste recycling industry is developing towards digitalization, intelligence, and collaboration.
Digital monitoring platforms are becoming a new trend in the industry.
Collaborative disposal models are also constantly evolving. In the Guangzhou Likeng Circular Economy Industrial Park, several leading companies in construction waste disposal, municipal solid waste power generation, metal recycling, and precast component production have been integrated, forming an industrial ecosystem for resource recycling.
The policy support system is becoming increasingly完善 (perfected/improved). Local governments have issued relevant plans and policies to promote the standardization and marketization of construction waste management. For example, Suining City plans to build two new construction waste resource utilization centers with a total designed processing capacity of 400,000 tons/year.
In Guangzhou, construction waste processing plants wash and screen excavated soil and slurry to produce finished sand. Concrete workshops further process this sand into low-carbon concrete, which is then sent to prefabricated construction workshops to become high-quality prefabricated products.
This industrial park, capable of processing 1.5 million tons of construction waste annually, has achieved a resource utilization rate of 92%, truly realizing the goal of “resource-based disposal and economical utilization.”
With technological advancements and improved policies, C&D waste recycling equipment is driving the construction industry towards a more environmentally friendly, economical, and sustainable direction.