Construction waste is produced in the social development process and also bothers the healthy development of society. Germany, Japan and Singapore have made some progress in the treatment and reuse of construction waste. In Germany, people have recognized that construction waste is also a kind of resource once you have treated it well; In Japan, construction waste can be divided into more than 20 kinds; In Singapore, people pay more attention to green building, and prevent the production of construction waste from its source.
The change of ‘waste mountain’ reflects the mindset conversion of construction waste treatment in Germany
There is an artificial mountain on the banks of the Elbe River in Hamburg, surrounded by green trees, and the white wind turbine blades rotate slowly. Who would have thought that decades ago, it was the yard where the rubble of the building was bombed in World War II, and it was later used to accumulate industrial waste and municipal waste?
Since the 1980s, the government has covered the garbage mountain with a plastic waterproof membrane, and laid the thickest 3 meters soil layer and planted vegetation. The biogas produced by the garbage is collected and converted into a part of the electricity source of a nearby copper smelter.
In 2011, an 8,000-square-meter photovoltaic power generation system was installed on the garbage mountain, and a higher-powered wind turbine replaced the old motor. The electricity generated by the two can meet the annual needs of 4,000 households. In addition, a 1000-meter long corridor has been built on the top of the mountain to become the newest place to see the panoramic view of Hamburg.
According to German law, people in the construction waste production chain needs to contribute to reducing waste and recycling. Building material manufacturers must design products that are more environmental and easy to recycle. For example, they produce plates in different lengths to avoid re-cutting in the future.
At present, Germany is one of the countries that perform best in construction waste recycling, with a recycling rate of 87%.
Different laws are applied in different construction waste treatment in Japan
Japan has more than 20 subdivisions of “construction by-products”, and the laws applicable to different types of by-products are different. For example, weeds are treated as general waste; wood and construction sludge are treated as construction waste; metals are treated as industrial waste; asbestos, fluorescent lamp transformers and other toxic and hazardous substances are treated according to special industrial waste, construction muck is not classified as waste.
Reducing waste generation on the construction site and reusing it as much as possible is the main principle of Japan. According to the “Building By-products Treatment Promotion Outline”, the contractor and construction party of the construction project are obliged to reduce the production of by-products during the construction process. Building materials suppliers and architects are obliged to produce and adopt renewable materials.
According to the survey, as early as the end of 2012, the recycling of construction waste in Japan reached 96%, of which the concrete recycling rate was as high as 99.3%.
Limited land space forces the government to increase recycling rates in Singapore
According to data from the Singapore National Environment Agency, the total amount of construction waste generated in Singapore in 2014 was approximately 1,269,700 tons, of which 1.26 million tons were recycled and the recovery rate was 99%.
For construction waste recycling plants, the Singapore Environment Agency also supports the rental of land, which recycles 80% to 90% of Singapore’s total construction waste recycling share. In order to maximize the recycling of construction waste, the Singapore government has also issued a code of building demolition, which is a set of procedural guidelines to help building demolition contractors better plan for demolition procedures.
Singapore focuses on reducing waste generation from its sources, and its related government measures include the Green and Elegant Program and the Green Building Mark Program. The former is a certification program launched in 2009 that scores building practitioners in terms of employee management, dust and noise control, and public safety. The latter began in 2005, which certification is specifically for buildings in the tropics, to assess the negative impact of buildings on the environment and to reward their sustainable development performance. The indicators include five aspects of energy conservation, water conservation, environmental protection, indoor environmental quality and other green features and innovations.
In the recycling of construction waste, crushing treatment is the key. In China, more and more building contractors use the mobile crushing plant to collect and crush construction waste. The mobile crushing plant can crush large pieces of material in multiple stages and screen according to certain discharge specifications, and the mobile crushing plant can process materials in the working site without having to move the materials away from the site for further processing, which greatly reduces the transportation costs.