Abstract:

This article was based on five typical construction and demolition waste recycling projects built and operated in Shanghai since 2018. Combining more than three years of operational practice, it analyzed the engineering elements of construction and demolition waste recycling projects, primarily focusing on renovation waste and considering demolition waste, from environmental protection, economic efficiency, and resource utilization perspectives. It mainly explored the impact of the choice of processing objects and scale on the project's environmental protection and economic efficiency, the impact of waste collection and transportation modes and the economic efficiency of recycled product applications on project site selection, and the key goals and production line setup points for project construction and operation. This provided a reference for the overall planning and operation of newly built projects of this type in cities and counties.

The study proposed that in the planning and operation of urban construction and demolition waste recycling facilities, based on the different generation patterns and characteristics of renovation waste and demolition waste, the processing objects, scale, and processes should primarily focus on renovation waste, while also considering demolition waste. For the collection and transport of renovation waste within a 50km service radius, a direct transport mode is adopted, without intermediate transfer or sorting stations. Recycled aggregate typically accounts for over 70% and is primarily used as raw material for producing building materials like bricks and mortar. The longer the transportation distance for recycled aggregate (S1), the higher the transportation cost and the lower the revenue from it. Sorting residue requiring incineration or landfill disposal accounts for 10-25%. The residue transport distance (S2) determines the required number of vehicles and is a key determinant of transportation costs. In a scenario where the residue transport distance increases from 1 km to 30 km, and the transportation cost per ton of residue increases by more than fivefold. Therefore, project site selection should be as close as possible to recycled aggregate application sites and residual waste disposal plants, and material utilization production facilities such as brick making and mortar should be set up within the plant if conditions permit. The key operational goals should include: 1) High quality of recycled aggregate; 2) A high resource recovery rate and a low residue rate (Note: comparing scenarios with 90% vs. 75% resource recovery rates, the difference in combined product revenue and residue disposal cost results in a 33.75 Yuan/ton difference in the net cost per ton of waste); 3)Effective control of dust and noise. During operation, economic calculations for renovation waste and demolition waste should be performed separately, and billing/settlement should be categorized accordingly.

Key words: decoration waste')">

decoration waste, overall planning and operation, environmental protection and economy, processing object and scale, project site selection, resource utilization goal