Construction Process for Cold Patch Asphalt Sand for Tank Bottom Anti-Corrosion
1. Placement
If paving a 10 cm thickness, 8 bags are required per square meter within the construction area. Specific placement and construction methods should follow the "Specification for Construction and Acceptance of Petrochemical Steel Tank Foundations and Subgrades" [SH/T3528-2014]. Asphalt sand (depending on compaction density, asphalt sand has a compacted density of 2.1 to 2.15 tons per cubic meter, each bag weighs 25 kg).
For tank bottom anti-corrosion asphalt sand, on the inner side of the ring wall (ring beam) of the tank foundation, before filling with anti-corrosion asphalt sand (especially when the ring wall is larger than the tank diameter, with some asphalt sand outside the main tank body), apply a layer of interface sealing agent. This serves to enhance the adhesion between the asphalt sand and the ring wall (ring beam) and improve the sealing and waterproofing effect, preventing water from seeping through gaps between the asphalt sand and the ring wall to the bottom of the asphalt sand foundation, which could cause tank bottom corrosion.
2. Leveling
After placing the asphalt sand bags, use a utility knife to cut open the packaging bags. Manually pour the asphalt sand into the area near the bags. Use a shovel for initial leveling, then use a screed board for secondary fine leveling (manual paving cost: 10 RMB/㎡). Finally, compact the surface. If the paving thickness exceeds 5 cm, it must be layered and compacted, with each layer not exceeding 5 cm in thickness. The flatness of the first layer may be slightly lower, but the surface flatness of the top layer must meet design requirements to ensure uniform distribution of the load borne by the tank bottom foundation.
3. Compaction
Compaction equipment must use a vibrating steel wheel roller. Avoid using simple compaction tools like plate compactors to ensure compaction density. During compaction, proceed from the outer edge inward in concentric circles to prevent the outer asphalt sand from loosening outward, thereby achieving effective compaction of the outer layer.
New Rail Filling Cold Patch Asphalt Sand
1. Base Surface Cleaning
Before filling, clean the filling areas on both sides of the rail thoroughly, removing any obvious debris, oil stains, loose rust, etc., to ensure strong bonding between the asphalt sand and the original base surface. If the track has been in use for some time and has rust, first use a hammer to knock off loose rust layers, then use an electric angle grinder brush to thoroughly clean the rust.
2. Applying Sealing Agent
Before filling with asphalt sand, use a brush to evenly apply a layer of interface sealing agent on the sides and bottom of the rail to prevent water seepage at the junction between the asphalt sand and the rail, and to provide rust prevention.
For filling asphalt sand on both sides of the rail, apply a layer of interface sealing agent on the two vertical surfaces (the sides where asphalt sand is filled) of the rail and the concrete casting surface. The interface sealing agent is asphalt-based, and asphalt itself provides excellent rust prevention for the rail, enhances adhesion between the asphalt sand and the two interfaces, and also serves as a seal for waterproofing at these interfaces.
3. Filling Asphalt Sand
Fill the asphalt sand into the areas on both sides of the rail to be treated. Use a trowel and shovel to level the surface of the asphalt sand. The filling material should be about 1.5 cm higher than the ground level.
4. Compaction
Use an impact rammer for vibration compaction. If the filling thickness exceeds 5 cm, pay attention to layered filling and compaction.