1. Basic composition and function
JH-flocculant is a powdered concrete admixture composed of water-soluble polymer materials, surface-active substances, etc. It has strong resistance to dispersion and good Mobility enables self-leveling and self-compacting of underwater concrete, suppresses 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. Functional Characteristics
The underwater concrete added with JH-flocculant greatly simplifies the construction process, makes underwater concrete construction land-based, and reduces the risk of construction to a great extent. The comprehensive cost can be reduced by more than 20%, and the construction period can be shortened by about 30%. Moreover, this technology can also realize special structures such as underwater thin-walled, narrow and special-shaped 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 mobility, 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 with C15~C40 underwater non-dispersible concrete according to the needs of underwater projects to meet the requirements of different construction functions. 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 does not corrode the 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
Suitable for 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 concrete volumes 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 the same method. Cement, sand and gravel are added to 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 1 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, JH-flocculant should be used The mixing amount is 2.0~3.0%. In other cases, it can be increased or decreased appropriately according to the drop of the concrete in the water.
(4) The mixing amount of 3.0% should be used for pile sealing, and the low mixing amount of 1.5-2.0% can be used for the pile body. Prevent pile breakage.
(5) Under normal circumstances, the coagulation time of JH-flocculant increases with the increase in dosage. If necessary, it can be used with a coagulant.
(6) Priority is given to 525# ordinary silicon cement , 425# ordinary silicon cement can be used instead when there is no supply. When the concrete has a drop under water, the cement dosage should generally not be less than 380kg/m3.
(7) When the underwater concrete is mixed with admixtures (slag or Fly ash) pumping performance can be significantly improved.
(8) The concrete ratio should be medium sand, with a recommended sand rate of 38 to 43%. The stone gradation generally adopts the range of 5 to 25 mm, and the maximum particle size does not exceed 40mm.
(9) Underwater construction equipment such as conduits and pumps can be used for continuous construction, and equipment such as opening hanging tanks, chutes, and trolleys can also be used for intermittent supply construction.
(10) Construction environment In principle, it is required to be in a still water state and the concrete drop should be less than 0.5m.
IV. Packaging and storage
1. This product is packed in a woven bag lined with plastic film and covered with kraft paper, 25kg per bag;
2 , Pay attention to moisture-proofing during transportation and storage. The storage period is generally 1 year, and it can continue to be used without moisture.
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