First, the working principle of shot blasting technology and equipment
Shot blasting refers to mechanically spraying the pellets (steel shots or grit) onto the work surface at a high speed and a certain angle, causing the pellets to impact the working surface, and then cleaning the inside of the machine through the airflow of the matching vacuum cleaner. A technique in which the pellets and the cleaned impurities are separately recovered and the pellets can be reused. The shot blasting machine is equipped with a dust collector, which can achieve dust-free and pollution-free construction, which not only improves efficiency but also protects the environment. The shot blasting machine can be divided into three types according to its walking form: hand push type, vehicle type and self type.
When the shot blasting machine is operated, by controlling and selecting the particle size and shape of the pellets, and adjusting and setting the walking speed of the machine, the projectile flow rate of the pellets is controlled to obtain different ejection strengths, and different surface treatment effects are obtained.
1.2 Control of surface treatment quality
The shot blasting process and equipment control the surface condition after treatment by three parameters depending on the surface to be treated. Select the size and shape of the pellets; the walking speed of the equipment; the flow rate of the pellets. The above three parameters cooperate with each other to obtain different treatment effects and ensure the ideal roughness of the treated surface.
For example: S330 steel shot, flow rate 10A, treatment of C50 concrete surface, can reach roughness 90; treatment of asphalt surface, can remove the oil layer, while achieving a roughness of 80; when dealing with steel, can achieve SA3 cleanliness standards.
Second, the application of shot blasting equipment
2.1 Surface treatment of concrete bridge deck
In Europe and the United States, the waterproof layer has been widely used in concrete bridge decking since the 1970s, which greatly reduces the damage caused by water seepage of concrete bridges and prolongs the service life of bridges. However, with the increase in traffic volume, there have been cases where the waterproof layer and the surface layer and the bridge deck have insufficient bonding strength to cause a change. In China, concrete bridges often have similar diseases, as well as loose and falling concrete due to water seepage, and steel corrosion. One of the causes of the above diseases is that the treatment of the concrete surface layer does not completely remove the surface residual material, and does not retain a certain rough surface to ensure the bonding strength of the waterproof layer and the bottom layer of the bridge deck.
The shot blasting process can clean and remove the floating surface and impurities of the concrete surface at one time. The most important thing is to simultaneously roughen the surface of the concrete to make the surface uniform and rough, and greatly improve the bonding strength of the waterproof layer and the concrete base layer. Moreover, in this process, the shot blasting process can fully expose the cracks of the concrete and the like, so that remedial measures can be taken in advance.
2.2 Maintenance of the tunnel
In China, the concrete pavement is generally made of waterproof concrete and materials that are resistant to fire and oil. At the same time, however, this also puts higher requirements on the anti-slip requirements of the long tunnel pavement. For the above two problems that are still difficult to solve in China, the shot blasting process is a treatment method with simple construction, small equipment investment, remarkable effect and environmental protection.
In recent years, there have been more and more projects using the shot blasting process to treat bridge decks and tunnels under the recommendation of users. In the waterproof pavement of concrete bridge decks, the shot blasting process has been the requirement of European and American national process specifications, and is gradually being gradually adopted in China. Acceptance, such as Chongqing Tongyu Tunnel, Guiyang Yingpanpo Tunnel, Kunshi Expressway Qingshuigou Tunnel, etc., all use the shot blasting process to maintain the concrete pavement.
2.3 Maintenance of asphalt pavement
Shot blasting equipment is widely used to improve the roughness and friction coefficient of asphalt pavement, thereby improving the adhesion of the pavement and ensuring driving safety. At the same time, it can also remove the attachments of asphalt pavement (such as fuel oil, engine oil, etc.) mainly used in the following aspects:
(1) During the construction of asphalt concrete overlay, the pretreatment of the road surface by shot blasting process can ensure the road surface is clean, and at the same time increase the surface roughness, strengthen the bond between the cover layer and the original road surface, and the durability of the structure is greatly improved. Increase; the slurry seal layer and the first shot blasting treatment when using the resin material cover surface can greatly improve the adhesive strength of the resin cover surface and the original base layer, improve the quality of the slurry seal layer, and prolong the service life of the road surface.
(2) The shot blasting process can be used directly on the asphalt pavement, for example, pulling on the surface of the turning section to improve the anti-sliding performance.
(3) It is possible to directly remove the surface oil from the asphalt pavement and improve the anti-slip performance caused by the oil spill.
(4) The shot blasting process can also be applied to the removal of the marking line.
In China, the influence of surface roughness on traffic has not received extensive attention. However, traffic accidents caused by road surface slippage are increasing every year. Shot blasting equipment can flexibly handle small-area road sections and fully restore its anti-sliding performance.
The surface of the asphalt treated by the shot blasting process not only cleans the attachments of various surfaces, but also increases the roughness of the asphalt surface and improves the performance of the asphalt pavement. Moreover, the equipment construction is simple and convenient, and flexible.
2.4 steel bridge deck anti-corrosion coating
The application of shot blasting technology in steel bridge anti-corrosion coating has been fully affirmed in China. Most bridges under construction and construction have been selected to use the shot blasting process to clean and roughen the surface before anti-corrosion primer or other spraying, such as the Yangtze River Second Bridge, Jiangyin Bridge, Junshan Bridge, Baishazhou Bridge, Shanghai Lupu Bridge and so on. The use of shot blasting to treat steel bridge decks can meet the SA2.5/SA3 steel sheet cleanliness requirements, and can control the roughness to meet the coating requirements, and the whole process is dust-free operation and easy to move.
2.5 municipal roads and paved roads
All kinds of road pavements in the city can be cleaned by shot blasting machine to remove the marking marks on the road surface. For the intersections with heavy traffic, the road surface can be roughened to improve the roughness and friction coefficient of the road surface.
2.6 Preventive maintenance of airport runways
Concrete and asphalt runways remove fetal tracks (except rubber), remove markings, restore and increase airport runway surface roughness, and increase runway friction coefficient.
Concerned about surprises
Label: Working principle and application of road shot blasting machine
Previous: Analysis of the characteristics of thick film circuit Next: Evaluation of the reliability principle of hydraulic rock drill
Jiangmen Dilin Lighting High-Tech Co., Ltd. , https://www.dilinlight.com