For Roadway Marking Removal The traditional method of roadway marking removal has been grinding. Others methods found around the world include shot blasting, sand blasting, soda blasting, and gas torching. When compared with waterblasting, the advantages are very clear.
Waterblasting: The needle-sharp water jets of a properly designed waterblasting system will reach like tiny fingers into the pores of the asphalt with remarkable effectiveness. While a small measure of the asphalt fines make break away, the surface plane of the asphalt remains intact. When driving over an area where a road marking was removed effectively by waterblasting, you will not feel any change in the surface of the pavement.
Environmentally Friendly: With properly designed captive waterblasting, the needle-sharp water jets pulverize the marking, reducing it to fine particles. At 40,000 psi, the chaos created within the captive environment enhances the effectiveness of the vacuum recovery. The result is precision removal and a very clean, nearly dry surface.
Runway Rubber Removal and Runway Cleaning: The traditional method of runway rubber removal has been with chemicals. In recent years, some of the chemical companies have developed bio-degradable detergents in an effort to reduce the hazardous impact of their products on the environment. However, when compared to properly engineered, captive waterblasting, the advantages of waterblasting are both significant and clearly understood.
Chemical: There are at least 3 primary factors to be considered when comparing rubber removal with chemicals to rubber removal by captive waterblasting. They are the Application Process, the Environmental and Infrastructural Impact, and the Cost.
Application Process: The cleaning of a runway with chemicals requires at least 3 steps and sometimes as many as 5. In any case, the amount of equipment and personnel required for the process will always be 3 or 4 times as much as required by proper waterblasting.
1) Initial Flushing: The process sometimes begins with an overall flushing of the runway to bring the surface temperature to a level recommended by the chemical manufacturer. This is, typically, only necessary in hot climates.
2) Chemical Application: The application of the chemical itself requires a specially designed truck or trailer. Typically, this equipment incorporates long, boom like outriggers for the spraying of the chemical across the width of the runway. Even the largest equipment used for the applying chemicals requires 2 or more passes to cover the area being cleaned.
3) Brushing: After the chemical has been given time to soften and breakdown the rubber deposits, the third step typically involves multiple passes with a rotating, steel bristled broom. The rotary action of the broom is meant to separate the softened rubber from the runway surface.
4) Rinsing: The rinsing of the runway is meant to keep the aircraft rubber, now mixed with the chemical, from settling back into the grooves and pores of the asphalt until the vacuum trucks make their pass.
5) Vacuum Recovery: The vacuum recovery of the residue that remains on the runway is usually the last step. However, vacuum trucks engineered for working on city streets, are not capable of lifting the remaining rubber and chemical mix from within the grooves of the runway. There is a growing concern that the long term use of chemicals breaks down the bitumen in runway asphalt. This creates a softening of the runway surface, ultimately reducing the useful life of the grooves.
The application process typically requires 3 or more trucks with as many or more operators. Furthermore, the runway being cleaned is not available for emergency landings during the cleaning process.