03. Vacuum impregnation reinforcement process for waste materials.
High pressure grouting, as the name suggests, is a process of injecting special adhesive into the interior of the waste material using a pressurized device, and strengthening the waste material after it solidifies. This process seals the cracks in the waste material, selects suitable glue injection points, and uses specialized equipment with a pressure of up to 30kg to ensure that the entire injection process is controllable and the crack filling rate is high, thereby ensuring that the waste material can be reinforced and smoothly sawn. The main equipment for high-pressure injection includes high-pressure injection machines and air compressors. The main materials include injection nozzles, crack sealants, waste material injection adhesives, and cleaning agents.
2. High pressure injection process flow
1. Pretreatment of waste materials: Most of the surface of the waste materials is adhered with mud, especially the mud left by the rope saw cutting will fill the cracks and grooves. These impurities will affect the subsequent flow of glue in the cracks, so cleaning is necessary. Thoroughly rinse the above areas with a high-pressure water gun to fully expose the cracks for subsequent operations. After washing, place the waste material in a sheltered environment and let it dry naturally.
After the crack sealing waste material is dried, the operator observes and analyzes the crack of the waste material, and uses a stone flipper to place the surface of the waste material without cracks as the bottom on the sleeper for easy operation. And use a marker to mark the position of the glue injection nozzle on the other five surfaces. The reservation of the position of the glue injection nozzle should follow the following principles:
2.2.1 The installation spacing of the same crack injection nozzle should be 20-40cm;
2.2.2 Glue injection nozzles should be installed at the bifurcation of cracks.
2.3 Preparation for glue injection: After reserving the position of the glue injection nozzle, take an appropriate amount of sealant (AB component) and adjust it evenly in a 1:1 mass ratio. Use a scraper to scrape the sealant into the crack outside the glue injection nozzle, and then apply a thick layer of sealant along the crack width area of 3-4 cm to ensure complete sealing of the crack. Finally, use sealant to install the injection nozzle in the reserved position.
2.4 After sealing the surface of high-pressure grouting cracks and installing the injection nozzle, let it stand at room temperature for 24 hours. After the adhesive has fully solidified, proceed to the high-pressure injection step. Firstly, check the airtightness, plug the glue injection nozzle of the same crack with a matching plastic plug, leave any compressed air interface, start the air compressor to charge the crack to 0.3MPa, observe the air leakage situation of the crack, and if there is no air leakage, proceed with the glue injection operation. If there is a leak, it is necessary to repair the leak point and wait for the sealant to fully cure again.
Therefore, crack sealing requires strict and meticulous operation to avoid affecting subsequent processes and reducing efficiency. Connect the outlet joint of the high-pressure glue injection machine to the glue injection nozzle, tighten and fix it properly. Open the high-level glue injection nozzle plug on the same crack to vent, mix the glue evenly in proportion in the mixing container above the glue injection machine, start the air compressor, open the air valve for high-pressure glue injection, and when there is glue flowing out at the high-level glue injection nozzle, close the air valve to stop the glue injection. Remove the outlet joint of the high-pressure glue injection machine from the glue injection nozzle, And quickly seal it with a plastic stopper to the vent area. Repeat the above operation for other cracks.
2.5 Precautions for operation:
2.5.1 When opening the air valve, pay attention to the inlet pressure of the pressure gauge. Generally, the operating pressure should not exceed 0.3MPa;
2.5.2 It is better to mix 1~2kg of glue in the middle note at one time. It is not allowed to allocate too much to cause waste. The operating time at room temperature is 1 hour. In addition, if there is too much glue mixed and not enough operation, it may cause glue explosion and aggregation, leading to abnormal situations such as blockage of the glue filling machine pipeline; After pouring, an appropriate amount of cleaning agent should be poured into the mixing container in a timely manner, the air valve should be opened, and the adhesive outlet joint should be placed into the mixing container at the same time, so that the cleaning agent can circulate to clean the equipment and pipelines, avoiding residual adhesive solidifying in the pipeline and causing equipment failure.
2.6 High pressure pouring adhesive has the following characteristics:
2.6.1 Low viscosity: The mixed viscosity is only 120mpa · s, and under high pressure, the glue can penetrate into the fine cracks inside the waste material;
2.6.2 Low temperature curing: It can also solidify well under winter temperatures of only 5 ℃;
2.6.3 Moisture curing: The internal moisture content of the waste material is generally high, and ordinary glue is prone to failure after entering, which does not have a good reinforcement effect. The molecular structure of the poured adhesive contains a large amount of hydrophobic structures, which can fully immerse and completely solidify the wet surface inside the waste material, enabling the damaged waste material to be firmly bonded internally; 2.6.4 High strength: After testing, Kesheng stone waste high-pressure grouting adhesive has been applied to wet stone – stone bonding, with a tensile shear strength greater than 15MPa, which is higher than the corresponding national standards.