High-pressure water jetting to remove high-strength anchor concrete for cables

In view of the difficulty, low efficiency and poor safety of removing high-strength Sealing concrete of cables by traditional methods, the technical applicability and technical economy of high-pressure Water Jet technology are analyzed first; secondly, model tests and real bridge tests of high-pressure water jet technology for removing high-strength Sealing concrete of cables are carried out. The results show that under the conditions of opening speed of 0.0075m3/h, water pressure of 250MPa and flow rate of 18L/min, the removal construction of high-strength sealing concrete of the lower head of a single cable can be controlled within 2d. High-pressure water jet technology can remove high-strength sealing concrete of cables safely, quickly, efficiently and environmentally friendly. Compared with manual chiseling, it can greatly save costs and improve efficiency. 

It can provide reference and reference for the maintenance, repair and reinforcement of bridges of the same type, and has a relatively high-pressure water jet technology. High-pressure water jet technology mainly uses ultra-high pressure water to remove a certain thickness of surface concrete, and at the same time controls the vibration and damage caused by the removal operation to the original structure within a reasonable range. As a "cold" cutting and crushing method, compared with traditional concrete removal technology, it has the advantages of easy operation, high control accuracy, energy saving, environmental protection, and safety. It has been rapidly developed in recent years and has broad application prospects. In some developed countries, high-pressure water jets have been used as a mature process to replace traditional pneumatic picks or mechanical breaking. 

In my country, the application of concrete removal is still in the initial and development stage. Concrete removal still mainly relies on pneumatic picks, mechanical crushing and other methods. These traditional methods have the disadvantages of high dust, large vibration, and difficult to control the damage to the original structure. Some working conditions are not suitable for traditional methods due to actual conditions. Research on the application of high-pressure water jet technology in civil engineering has practical significance.

High-pressure water jet technology is mainly divided into three types based on the working medium: pre-mixed abrasive jet, high-pressure pure water jet and pulse pure water jet, each with its own advantages and disadvantages. Compared with pre-mixed abrasive jet and pulse water jet, the advantages of high-pressure water jet are more obvious, mainly because the anchor head at the end of the cable system beam is the key stress-bearing part of the bridge structure, and the stress distribution is relatively complex. 

When removing the anchor concrete, it is necessary to strictly control the scope of operation to ensure the safety of the bridge structure. The amount of material stripped from the surface of the pulsed pure water jet component is large and irregular, and the crack extension cannot be completely controlled. The pre-mixed abrasive jet has a great impact on the Mixing Chamber and pipeline, and has high requirements for equipment, which will increase the cost of removing the high-strength anchor concrete of the cable. 

At the same time, the rich achievements and experience that high-pressure water jet technology has accumulated in tunnel maintenance and road surface removal have provided support for the application of high-pressure water jet technology in the removal of high-strength anchor concrete of the cable.