工程渣土资源化基础问题与低碳技术路径

Basic problems and low-carbon technical path of construction spoil recycling

本文针对国内工程渣土排放量大但高附加值利用率低、资源化过程碳排放高等难题,探究了技术层面的基础问题,并提出了可行的创新技术路径:阐明了工程渣土的定义、成分与危害,并将现有资源化处置技术概括分成4类;梳理了国内近20年工程渣土的4类处置与资源化技术发展脉络与地区差异,分析了技术的主要研发与应用方向,明晰并界定了技术术语;进一步探明了工程渣土的基本性质,厘清了直接再利用、简单处理与改良、固化以及烧制4类技术的科学原理.根据国内工程渣土的处置现状,深入剖析了工程渣土资源化利用率低在技术层面的基础问题,分析了资源化处置的减排潜力.结合我国的碳达峰、碳中和战略,提出了多路径多场景利用、协同处置、数字化技术赋能等创新性解决路径与高附加值策略,并建议了具有潜力的低碳新技术以及工程渣土综合利用的低碳技术路径.

In the past 20 years,China has made tremendous progress in urbanization and infrastructure construction,but it has also generated a large amount of construction spoil that is difficult to handle.The annual emission of construction spoil in China is huge,but its high value-added resource utilization rate is very low.Currently,it is still mainly landfilling and stacking to construction spoil storage sites,and the current disposal process generates a large amount of carbon emissions.In view of the national strategy of carbon peak and carbon neutral,as well as the current situation of low resource utilization rate of construction spoil,the basic problems at the technical level are explored and the feasible and innovative technical path was put forward.Firstly,the definition,composition and harmfulness of construction spoil are expounded.The existing disposal and recycling technologies of construction spoil are divided into four types,including direct reuse,simple treatment and conditioning,solidification and sintering.The development context and regional differences of four types of disposal and recycling technologies of construction spoil in China in the past 20 years are combed,the main research and application directions of those technologies are analyzed,and the technical terms are clarified and defined,and the shortcomings of previous relevant research are pointed out.The basic properties of construction spoil are intensively introduced and the scientific principles of four types of disposal and recycling technologies including direct reuse,simple treatment and conditioning,solidification,and sintering,are further revealed.And we suggested that low-carbon solidification technology and carbon-reduction sintering technology are the future development trends.Based on the case study of the Pinglu Canal,it is found that the current situation of disposal of construction spoil in China is still relatively preliminary.According to the current situation,the basic problems of low utilization rate of construction spoil at the technical level are analyzed,mainly including insufficient space,insufficient analysis of demand,high disposal costs,and insufficient attention to environmental impacts of the disposal of construction spoil.Then the potential of carbon absorption and sequestration of construction spoil itself and the possibility of reducing carbon emissions in the process of resource utilization and disposal of construction spoil is analyzed.Finally,to address these basic problems and in combination with China's dual-carbon strategy,innovative solutions and high-value-added strategies such as recycling at multi-scenario through multi-path,co-processing,and digital technology empowerment are proposed,new potential technologies with low-carbon and carbon sequestration such as raw earth construction and 3D printed soil are suggested,and new technology paths for comprehensive utilization of construction spoil including low-carbon solidification,carbon reduction sintering,and other technologies are put forward.With the continuous development of the domestic construction industry,the recycling of construction spoil will provide a new direction for saving natural resources,alleviating urban environmental pressure,and achieving green construction.