Construction waste should make up for the shortcomings of "waste-free" disposal
The huge amount of construction waste generated by old demolitions, new house renovations, road renovations, etc. is mixed and cannot be directly used without disposal. It is dumped at will, which is more harmful to the environment. Moreover, due to the serious shortage of local disposal capacity, illegal dumping problems occur frequently in many places and across regions and continue to be proscribed repeatedly.
The disposal and utilization of construction waste is an old problem, and many effective explorations have been carried out in various places in recent years. Xuzhou, northern Jiangsu, where the author is located, is one of the first batch of national pilot projects to build a "waste-free city". In the process of continuously deepening the construction of a "waste-free city", it has formulated and promulgated the "Measures for the Management of Urban Construction Waste in Xuzhou City" to accelerate the entire management of construction waste and achieve good results in promoting the resource utilization of construction waste.
Walking into the construction waste resource processing workshop, I saw that the waste stone production line, demolition waste production line, and decoration and decoration waste production line were carrying out crushing, sorting, and screening. The production process of these equipment and facilities is not complicated. After crushing and screening the construction demolition and decoration waste, it is sorted into recycled aggregate, general combustibles, scrap metal and sediment materials, and the comprehensive utilization rate of resources exceeds 90%. Among them, recycled aggregate is used as raw material and can be sold directly, or concrete or un-fired bricks can be produced.
The end of construction waste disposal is brick making. After mixing, mixing, high-pressure pressing, and kiln maintenance, recycled aggregate becomes finished bricks with good appearance, texture and high compressive strength. Using a tunable pressing mold process, the brick making line can produce different types of finished bricks such as colored floor bricks, curb stones, slope protection bricks, and load-bearing blocks, which can meet different uses such as house construction, greening and gardening, high-speed slope protection, and river slopes.
Through overall planning and layout, Xuzhou City carries out centralized, standardized and resource-based treatment of construction waste. It not only solves the pollution problem caused by the dumping of construction waste, but also produces recycled building materials that can also feed back into urban and rural construction. What impressed the author most was that during the upgrading and renovation of cement pavements in rural areas in the county, the updated cement blocks from rural roads were piled up all over the mountains and fields on the roadside. After a simple recycling line was completed, the cement blocks were quickly "eaten and squeezed" and restored to sand and gravel.
"Garbage is a resource placed in the wrong place." Construction waste is processed and turned into building materials, becoming the "hot cake" of disposal and utilization companies. Recycling not only produces economic value but also produces environmental benefits. The recycling of sand and gravel greatly reduces the damage to the natural environment caused by re-mining. Based on the natural accumulation height of 5 meters, 10,000 tons of construction waste covers an area of two acres. For every 10,000 tons of construction waste processed, it can bring nearly 900,000 yuan in new output value.
Of course, we should also note that differences in city sizes and regions vary in the capacity of construction waste disposal. The reason why some large cities have become places where garbage is frequently dumped across provinces is precisely because of the large amount of garbage but the space for garbage disposal is limited. Establishing market-based mechanisms similar to carbon emissions trading and emissions trading, and promoting legal cross-regional cooperation in construction waste disposal are also not a good disposal measure.
Construction waste is a problem that must be solved at a certain stage of urbanization development. As long as urban and rural areas continue to be upgraded and renovated, construction waste will definitely be generated. Today's projects may be construction waste someday in the future. Make up for the shortcomings of "waste-free" consumption and disposal of construction waste, and open up the difficulties and blockages of construction waste resource utilization through "waste-free" construction. Construction waste is sent to resources, and the "urban disease" of construction waste will naturally also be cured.
