Among the existing roads, asphalt pavement accounts for the vast majority, paving and maintaining these pavements requires a large amount of asphalt, asphalt is a petroleum product, and petroleum is a non-renewable resource. Therefore, with today’s more and more attention to resources and the environment Therefore, it is only logical to study the regeneration of asphalt.
On-site thermal regeneration of asphalt pavement is one of the asphalt recycling technologies, and it is also one of the hot topics. At present, the on-site thermal regeneration equipment in use in China mainly includes regeneration trains, hot wall comprehensive maintenance vehicles, and asphalt pavement heating plates.
The regenerative train is a thermal regeneration unit that works continuously. It operates in a one-stop operation of heating, milling, mixing, paving, and compacting. The running speed is 1-2m/min. It is mainly used for the overall renovation of the road surface, which is expensive and complicated to operate;
The hot wall comprehensive maintenance vehicle and the heating plate are used for road surface repair and intermittent work, the former is with a car chassis, and the latter is portable or trailered. These devices are not only expensive, but the heating effect and operating costs are not ideal.
Asphalt pavement is widely used in modern cities and highways, it can be paved quickly and has the greatest impact on traffic. However, long-term use is also prone to problems such as cracking and aging. The advantage of asphalt is that it can be recycled and reused.
Scope of application
1. It can regenerate and repair the cracks, cracks, grooves, loose cracks, and other diseases of the asphalt concrete pavement in the later stage.
2. It can solve the thermal joint problem in the construction and maintenance of asphalt concrete pavement.
Performance and Features
1. RIM-4 Asphalt Pavement Recycling Repair Machine adopts infrared heat radiation heating according to the remarkable characteristics of asphalt pavement that is the black body and rough surface. Asphalt pavement with rough surface and blackened surfaces are designed with infrared thermal radiation heating, which has obvious advantages such as low reflectivity, high thermal efficiency, low energy consumption, and high economic benefit.
2. LPG propane gas is used as fuel, and the uniquely designed fuel nozzle and energy-saving and environment-friendly heater are well mixed with air and then fully burned so that it will not produce smoke and other harmful substances to the environment and human body. No pollution, it is an environmental protection and energy saving product. Heating the asphalt pavement with infrared heat radiation, the softening speed is fast (5-8 minutes), the softening depth of the asphalt pavement can reach more than 5 cm, the heating is uniform, and the scorching and aging of the asphalt surface are avoided.
3. Recycled repairs not only have good repair quality (hot seams) but also can save raw materials and reduce transportation costs.
Control method
For the gas combustion system, the first necessary control system should have functions such as automatic ignition, flame monitoring, flameout protection, and safety alarm. At present, the pavement heating equipment on the market is not very good in this aspect. Most of them only have a simple ignition function, and generally do not have flameout protection and safety alarm functions. Some even have no electronic ignition function, and Bunsen burners need to be manually used Ignition, is easy to cause safety accidents, especially it is easy to cause deflagration and burns the operator. We recommend that companies that design and produce heating panels (walls) improve this aspect. In fact, these are very mature technologies and are not difficult to do.
Since the part of the infrared rays with shorter wavelengths is difficult to penetrate into the deep layer of asphalt, and the high-temperature smoke directly scours the surface layer of the road surface, and asphalt concrete is a poor conductor of heat, the surface temperature of the asphalt will rise sharply in a short period of time. If it is not controlled, it will cause the oxidation of asphalt and even catch fire.
In this regard, the more common method is to use intermittent heating, that is, heating for a few minutes and then stopping for a few minutes, then continuing heating, and so on, until the required temperature and softening depth are reached. Regarding the control of this part, most of the manufacturers’ products do not have it, and basically, adopt the method of the manual shutdown. In fact, there are two ways to meet this requirement, one is to use a time controller or PLC control, and the other is to use temperature control, that is to control the heating and stopping of the system by detecting the temperature of the surface asphalt. The former is simple and reliable, but the operator needs to adjust the heating time and intermittent time according to the road conditions. The latter is more complicated, and the current temperature sensor is not suitable for this working method, the reliability needs to be improved, and it is temporarily difficult to promote.
