There are a lot of waste tires piled up in the corner. If they are not treated for a long time, this kind of environmental pollution is called "black pollution", which is very harmful. Waste tires will not only produce toxic substances to pollute nearby water sources and soil, but also release toxic substances due to aging collapse and fire, endangering personal safety. The disposal of waste tires is a recognized environmental problem. In order to deal with these waste tires, countries have racked their brains. Part of it is burned as fuel, part of it is pyrolyzed to obtain by-products such as carbon black, part of it is used as sound deadening wall and buffer wall, part of it is used to make plastic floor, and part of it is used to produce new tires after treatment. Of course, it is also used as building materials and subgrade, breakwater, reef and so on. There are two ways to use it here, one is to directly crush it into powder or granular mixed asphalt to pave the road, and the other is to directly cut it and use it as subgrade. Both methods are used in America. Modern waste tires are composite products composed of fiber, steel and various vulcanized rubber. Recycling requires a lot of processing procedures and the cost is very high. During the downturn of the rubber tire market, it was almost a loss-making business.
Therefore, Americans don't hate using it directly as a roadbed, which can directly help the United States consume millions of waste tires every year and even apply for a patent for it. Granite Construction Company, FNF Construction Company and Grassland Valley Company are all representatives of mixed paving technology in the United States. Therefore, it is entirely the demand for environmental protection that drives the phenomenon of paving roads with tires in the United States, rather than actively inventing this technology. Of course, paving the road with waste tires is not a matter of crustily skin of head, otherwise it will end up like a coral reef at the beginning. It has many advantages and feasibility to bury waste tires in the road. In the long-term use of the road, due to repeated rolling of vehicles, especially the passage of some heavy vehicles such as low-end trucks, as well as the influence of temperature and the erosion of natural environment, it is easy to destroy the road surface and leave some uneven pits and cracks on the surface. These potholes and cracks will not only affect the driving experience and safety, but also hurt the subgrade and affect the service life of the highway if they are not treated in time. In some sections with more heavy vehicles, regular road repair work will undoubtedly consume a lot of manpower and material resources, so improving the road's compressive capacity at the beginning of road construction is the best solution.
What Americans think of is to install a "skeleton" like a house on the road. A large number of discarded tires is undoubtedly a good choice. American engineers cut waste tires into easy-to-arrange shapes, then filled them with gravel and paved them with asphalt, and applied for technical patents for this purpose. Facts have proved that this kind of "skeleton" road is extremely strong, which is not only twice as hard as ordinary roads, but also can bear the extra load per square meter 150 tons and reduce the maintenance cost by 75%. Using waste tires to fill the road surface greatly saves the use of building materials, and the average concrete consumption per cubic meter can be reduced by 30%, and the cost is about 20 dollars. At present, the widely used method is to crush waste tires into powder, particles or fragments, and then mix asphalt or construction waste as road filler.
Taking Heda Expressway in China as an example, tires are mixed with gravel and soil generated by nearby tunnel excavation and pressed into subgrade. Then, the waste tires are crushed by rubber asphalt technology, and various polymer modifiers are added to react with matrix asphalt at high temperature to produce an improved asphalt binder for paving roads. This road not only saves resources, basically does not need to draw materials from other places, but also is durable and basically maintenance-free in the first ten years. More than 654.38+00 million tires are used in hybrid road construction in the United States every year. The road mixed with waste tires not only has light weight, good thermal insulation, good water permeability and compressibility, but also improves the skid resistance, firmness and toughness of the road surface, reduces driving noise, saves a lot of materials and consumes a lot of waste tires, which can be described as killing two birds with one stone.
Of course, using this technology also has disadvantages, that is, the pavement is easy to accumulate temperature and even cause fire, but reducing the size of rubber particles can effectively solve this problem. Although China began to recycle waste tires a long time ago, up to now, there are still 5% waste tires that have been piled up for a long time and have nowhere to be used, which is three or four percentage points lower than that of advanced foreign countries. This is not only a technical backwardness, but also a deficiency in the establishment of relevant institutions and the customization of laws. The use of waste tires in Europe, America and other countries is not only more extensive and technologically advanced, but also worth learning from in management. The government has well connected the relationship between tire producers and producers, and will also subsidize the recycling of waste tires, thus ensuring a virtuous circle of tire recycling industry. Most of the enterprises dealing with waste tires in China are small and medium-sized enterprises, with insufficient scale, weak technical force and relatively scattered, which are basically semi-public welfare undertakings and still have a way to go.