The waterproof coagulant is a liquid waterproofing agent formulated with water glass as the base material and an appropriate amount of water, copper sulfate, and potassium dichromate. It is also called a Vanadium waterproofing agent.
The preparation method and quality requirements of waterproof coagulant are as follows:
(1)Preparation method
Heat the quantitative water to 100°C according to the mixing ratio, then put the acetate sulfate and potassium dichromate into the water and continue heating, stirring constantly. After all is dissolved, cool to 30°C~40°C, then pour the solution into the weighed solution. Pour into a measured amount of water glass, stir evenly to make it sit for half an hour before use.
(2)Quality requirements
The prepared relative density of the coagulant is about 1.50.
2. Four-alum waterproofing oil (four-alum waterproofing agent)
Four-alum waterproof oil is a kind of grass formulated with sodium silicate (water glass) as the primary material, adding an appropriate amount of water and four alum-based materials (which can generate heat, separate water, and quick-dry) according to a specific mixing ratio into a green liquid. It has the effect of accelerating coagulation and can be mixed with cement to make waterproof cement slurry. It can be added to cement mortar or concrete to form waterproof mortar and waterproof concrete to block leaks and cracks. Four-alum waterproofing oil is simple to prepare, has vast sources of materials, is convenient for construction with low-priced.
The critical points for using four-alum waterproof oil are as follows:
(1) Prepare waterproof cement mortar
Waterproof cement mortar is formed after the cement is mixed with four-alum waterproofing oil(generally, the setting time is about 40 seconds).
(2)Construction operation methods
① After kneading the waterproof cement glue in your hand until it becomes glue-like, immediately plug the cracks and holes, press firmly inward along the holes (it is best to twist and press), and seal the holes tightly with the cement glue.
② If a large leakage hole is blocked, the hole must be blocked with a large piece of waterproof cement mortar first, and then the hole must be repaired according to the above method.
(3) Precautions when using waterproof oil
① The water glass concentration is related to the solidification time of the waterproof material. The best Baume degree is between 42 and 48. The smaller the Baume degree, the faster the solidification time. The solidification time will slow if it is less than a particular range.
② The solidification time is related to the climate. The solidification time is fast in summer, so special attention should be paid during construction. Generally, the setting time of four-alum waterproof cement glue is about 35 seconds in summer and about 1 minute in winter.
③ Use four-vitriol waterproofing oil to prepare waterproofing materials, and grade 42.5 ordinary Portland cement should be used.
④ If the wall contains a large amount of leaking water without a supply source, holes must be drilled first to drain the water before making a waterproof layer.
⑤ Do not use four-alum waterproofing oil as a waterproof layer for domestic water storage tanks.
⑥ Cement mortar with waterproof oil should not be diluted with water during operation; otherwise, bonding and detachment will occur.
4、water based capillary inorganic waterproofing agent
The water-based capillary inorganic waterproofing agent is based on an alkali metal silicate solution, adding catalysts and additives, and is made through a mixing reaction. It has permeability and can seal cement mortar and concrete’s capillary channels and cracks.
The characteristics of this product are as follows: This material is a colorless, odorless, non-toxic, and non-flammable sealant, which can achieve long-term waterproofing effects; it can prevent the erosion of the cement concrete surface by salt, acid rain, and gases such as sulfur dioxide and carbon dioxide in the atmosphere; can improve the strength of concrete. It can increase the strength of cement by 15% in 7 days and 28% in 1 month. Spraying it on the surface of concrete can prevent the water in the cement from evaporating too quickly and make the cement fully hydrated, thereby obtaining sufficient strength and avoiding cracks; this product also has the functions of resisting water absorption, resisting weathering, improving anti-pollution capabilities, and is easy to clean.
The limitations of this product are that it is only suitable for concrete and masonry, cannot seal asphalt, metal, and wood products, cannot penetrate plexiglass or non-porous rubber-based paints, cannot be used on enamel masonry, and cannot be used in freezing temperatures.
Special treatment is required if this product is used in loose concrete masonry.
Spraying this product on the water’s backside can increase the specimen’s anti-seepage pressure by 0.3MPa, and on the water-facing side can increase the anti-seepage pressure by 0.4MPa. Therefore, it is suitable for waterproofing and moisture-proofing of various buildings with cement surfaces, concrete structures, and brick structures; waterproofing of exterior and interior walls of buildings; and is most effective in waterproofing and repairing basements or underground projects. In general, M1500 can withstand the water pressure (approximately 30.48m) on the 5th and 6th floors of the basement. Specific examples are as follows: leakage prevention of cement roofs and water storage devices such as warehouses, basements, water towers, ammonia pools, and biogas pools; waterproofing, seepage prevention, and leakage prevention of tunnels, pipelines, and other underground buildings poured with concrete; used in runways, hangars, highways, bridges, and docks; used in cement ships, not only can prevent leakage but also slow down the corrosion of steel bars.
Construction method
① Spray sufficient water on the surface to be constructed, then spray the M1500 waterproofing agent after 30 minutes.
② Use a low-pressure sprayer (such as a pesticide sprayer) to spray the entire surface twice (spray the second time after the first one and before it dries to ensure that the entire surface is evenly saturated. Small-area working surfaces can be brushed with a brush).
③ The surface needs to be moistened with water after spraying the M1500 waterproofing agent for 3 hours or before dries. Especially in the high-temperature season in summer, pay more attention to watering and moistening, but the amount of watering should not be too large to avoid diluting the agent’s potency. After 24 hours of construction, white impurities can be seen on the concrete surface.
The number of wetting times per day is usually 6 to 7 times in summer, 1 to 2 times in other seasons, and a total of about 3 days of maintenance is required.
④ Reference dosage of materials
A waterproofing agent of 0.22kg to 0.25kg is required for every 1m² of waterproofing layer area. A waterproofing agent of 0.44kg to 0.50kg is required for every 1m² of waterproofing layer area if the waterproofing layer needs to be sprayed twice.
⑤ Precautions
a. It can be constructed on wet surfaces but not in flowing water. If flowing water is encountered, it should be stopped before construction can begin.
b. It cannot be mixed with cement mortar; otherwise, it will be invalid.
c. The sealant can penetrate oil-based or water-based paint without affecting the paint color.
d. For newly poured concrete, after the formwork is removed, the sealant can be sprayed evenly on the entire surface until it is saturated. Cast-in-place roofs and newly plastered cement surfaces are best sprayed before drying.
(5) Silicic acid (SiO₂) powder-based waterproof agent
Acceptable silicate powder additives such as fly ash, volcanic ash, diatomite, and silica fume are waterproof agents that directly fill the gaps between concrete or mortar particles, improving the compactness and impermeability of concrete and mortar.
These silicic acid powders are incorporated into concrete and mortar, improving their micro-gradation and workability. In particular, fly ash can significantly reduce unit water consumption, porosity, and finely mix minerals. It can promote the hydration reaction and fill the pores in the concrete with the volcanic ash reaction products, significantly improving the long-term impermeability. Silica fume is a highly active fine admixture with a specific surface area of up to 20m²/g, almost all of which is SiO₂, and is in an active amorphous state. For example, adding 10% silica fume can improve the water tightness of concrete. Using fine mineral additives in combination with superplasticizers can improve the compactness and impermeability of concrete.
