1. Basic composition and performance
JH-flocculant is a powdery concrete admixture composed of water-soluble polymer materials, surface-active substances, etc. It has strong resistance to dispersion and good Fluidity enables self-leveling and self-compacting of underwater concrete, inhibits the dispersion of cement and aggregate during underwater construction, and does not pollute the construction waters. The compressive strength of underwater concrete with JH-flocculant added can reach more than 70% of the strength of land-based concrete with the same proportion when the water drop is 0.3 to 0.5m.
2. Performance characteristics
Adding JH-flocculant to underwater concrete greatly simplifies the construction process, makes underwater concrete construction terrestrial, and reduces the construction time to a great extent. risk, reducing the overall cost by more than 20%, and shortening the construction period by about 30%. Moreover, this technology can also realize special structures such as thin-walled, narrow and special-shaped underwater structures that were previously impossible to construct.
1. Concrete added with JH-flocculant has excellent resistance to dispersion in water. It does not disperse or segregate when falling in water. The cement rarely loses and does not pollute the environment. Concrete has good fluidity, and can be self-leveling and self-compacting when cast in water. There is no need for underwater vibrating, which simplifies the underwater construction process.
2. JH-flocculant can be formulated into C15~C40 underwater non-dispersible concrete according to the needs of underwater projects to meet the requirements of different construction performance. The slump of non-dispersible concrete under water can reach 18-24cm, and it does not bleed or segregate. The initial setting is 5 to 40 hours, the final setting is 10 to 50 hours, and the setting time is adjustable. The impermeability can reach S10 or above, and the corrosion resistance coefficient is not less than 0.85.
3. JH-flocculant has good compatibility with other admixtures. D300 freeze-thaw resistant concrete can be prepared by adding air-entraining water-reducing agent. It has no corrosion on steel bars and does not pollute the construction waters. After inspection by the health department, the flocculant is non-toxic and can be used in drinking water projects.
3. Construction instructions
1. Scope of application
Applicable to various underwater pouring concrete projects.
JH-flocculant can be used for caisson bottom sealing, cofferdams, caissons, riprap grouting, underwater diaphragm wall pouring, underwater foundation leveling and filling, RC slabs and other large-area underwater construction joint-free projects. Diameter cast-in-place piles, docks, dams, reservoir repairs, drainage outlet waterproof impact reinforced bottom plates, underwater caps, seawall revetments, slope protection, pile sealing and leakage sealing, and underwater projects that are difficult to construct with ordinary concrete.
JH-Underwater concrete is not limited by water depth, construction surface, and concrete volume (various underwater projects with a maximum depth of 37.8m and a concrete volume ranging from a few cubic meters to several thousand cubic meters have been constructed. During tidal section concrete construction, It is not affected by the tide.
2. How to use
(1) JH-flocculant is a solid powder with a dosage of 1.0 to 3.0% (accounting for the weight of dry cement powder). It should be mixed with method, add the cement and sand into the forced mixer at the same time.
(2) The mixer should be a forced mixer, and the mixing time is generally 3 minutes. If a self-falling mixer is used, the mixing time should be extended by one time.
(3) When using traditional underwater construction equipment such as conduits and pumps, JH-flocculant can be used at a low dosage of 1.5 to 2.0%; when using land construction equipment such as hanging tanks and chutes, that is When there is a drop in the concrete in the water, a dosage of 2.0 to 3.0% should be used. In other cases, it can be increased or decreased appropriately according to the drop in the concrete in the water.
(4) A dosage of 3.0% should be used for pile sealing. The pile body adopts a low dosage of 1.5-2.0% to prevent pile breakage.
(5) Under normal circumstances, the coagulation time of JH-flocculant increases as the dosage increases. It can be used with a coagulant if necessary.
(7) When underwater concrete is mixed with admixtures (slag or fly ash), the pumping performance can be significantly improved.
(8) The concrete proportion should be medium sand. , the recommended sand rate is 38 to 43%, the stone gradation is generally in the range of 5 to 25mm, and the maximum particle size does not exceed 40mm.
(9) Underwater construction equipment such as conduits and pumping can be used for continuous construction. Open hanging tanks, chutes, trolleys and other equipment can also be used for intermittent supply construction.
(10) In principle, the construction environment requires still water conditions and a concrete drop of less than 0.5m.
IV , Packaging and Storage
1. This product is packed in woven bags lined with plastic film and kraft paper, 25kg per bag;
2. Pay attention to moisture-proofing during transportation and storage. The storage period is generally 1 year. Can continue to be used if it does not get wet.
</p