Cementitious capillary crystalline waterproofing coating

Cementitious capillary crystalline waterproofing coating

Cementitious capillary crystalline waterproofing coating

 

It is a green and environmental protection with long-term waterproof, corrosion-resistant anti-aging and steel protection. Have ability to permeate 2nd times and self-repair. Easy and quick to apply, non-pollution.

 

Cementitious capillary crystalline waterproofing coating is a grey mealy coating, with chemical active composition added and ordinary Portland cement based. Its action principle is mainly replies on porosity, under the action of water, chemical active composition can infiltrate into the surface then reacts to insoluble crystal, such as ettringite. The chemical active composition can boost hydration of cement, forming a large number of crystals to fill the void. Then the water can’t permeate into the cement to meet waterproofing objectives.

 

Cementitious capillary crystalline waterproofing coating has a good cementing property, a good workability on the smooth reference plane, burr reference plane, outside reference plane, inside reference plane, dry reference plane, wet reference plane, or water control reference plane.

 

Sphere of application:

It can widely be used in tunnels, dams, reservoirs, power plants, nuclear power plants, cooling towers, viaducts, bridges, runways, pile foundations, wastewater treatment facilities, civil engineering, and other concrete construction waterproofing.

 

Introduction

The main feature of cement-based penetrating crystalline waterproofing materials is penetrating crystallization. General surface waterproofing materials may gradually lose their waterproofing effect after a period of aging, while cement-based penetrating crystalline waterproofing materials will lose their waterproofing effect under the guidance of water. , using water as the carrier, with the help of strong permeability, it transmits and fills in the capillary tubes of the concrete micropores, undergoes physical and chemical reactions, forms water-insoluble crystals, and combines with the concrete structure to form a closed waterproof layer as a whole, blocking any incoming water. The direction of water flow and other liquid erosion not only achieves long-term waterproofing and corrosion resistance but also protects steel bars and enhances the strength of concrete structures. The performance characteristics of cement-based penetrating crystalline waterproof materials produced by different manufacturers are also slightly different, but they mainly have the following eight performance characteristics.

 

Eight performance characteristics of cement-based penetrating crystalline waterproofing materials

 

1.    Has double waterproof performance

The penetrating crystals produced by cement-based penetrating crystalline waterproofing materials can penetrate deep into the concrete structure and block the structural pores. No matter how deep the penetration is, it can play a waterproofing role inside the structural layer; at the same time, it acts on the base surface of the concrete structure. Due to its micro-expansion performance, the coating can compensate for shrinkage and make the structural base surface after construction also have good anti-cracking and anti-seepage effects.

 

2. Extremely resistant to water pressure

It can withstand strong water pressure for a long time. The test results of some products show that when two layers of cement-based penetrating crystalline waterproof materials are painted on a concrete specimen with a thickness of 50mm and a compressive strength of 13.8MPa, it can withstand at least 123.4m of water head pressure. (1.2MPa).

 

3. Has a unique self-healing ability

Cement-based permeable crystalline waterproofing material is an inorganic waterproofing material. The crystals formed will not age. The crystal structure can still activate the cement when exposed to water many years later. The new crystals produced will continue to be dense, sealing or resealing cracks less than 0.4mm, complete the process of self-repair.

 

4. It has the functions of anti-corrosion, aging resistance and protection of steel bars.

Chemical attack of concrete and corrosion of steel bars are inseparable from the penetration of moisture and chloride ions. The permeable crystallization and self-healing capabilities of cement-based permeable crystalline waterproofing materials make the concrete structure dense, thereby minimizing the intrusion of chemicals, ions and moisture and protecting reinforced concrete from erosion.

The water-insoluble crystals produced by cement-based penetrating waterproof materials do not affect the ability of concrete to breathe, and can maintain normal ventilation, moisture removal, and dryness inside the concrete structure. It also extends the length of the building while keeping the steel bars inside the concrete from being eroded. service life of the object. At the same time, concrete structures treated with cement-based penetrating waterproof materials can effectively prevent spalling, weathering, and damage caused by freezing and thawing.

 

5. Has a reinforcing effect on concrete structures

The structure after construction with cement-based penetrating crystalline waterproofing materials is not a reactivation of the crystal structure, but activation of unhydrated cement, which increases the density and strengthens the structure. Generally, it can increase the strength of concrete by 20%. ~30%.

 

6. Has long-lasting waterproofing effect

The physical and chemical reactions produced by cement-based penetrating waterproof materials are initially on the surface of the working surface or adjacent parts, and gradually penetrate into the interior of the concrete structure as time goes by. The penetration depth of each manufacturer’s products ranges from 10 to 30cm (some manufacturers indicate that their products have a greater penetration depth). Under normal circumstances, the crystal structure formed will not be damaged, and its performance is stable and does not decompose. Even if the waterproof coating is worn or scraped off, it will not affect the waterproofing effect because its active ingredients have penetrated deeply into the concrete structure. , so its waterproofing effect is long-lasting.

7. Comply with environmental protection standards, non-toxic and pollution-free

Cement-based penetrating crystalline waterproofing material is a non-toxic, odorless, harmless, and pollution-free environmentally friendly product that can be tested according to the general standards for environmentally friendly (green) building materials.

 

8. It has the advantages of simple construction method, saving labor and time.

The requirements for the base surface are simple during the construction of cement-based penetrating crystalline waterproofing materials. There is no need for a leveling layer on the concrete base surface; there is no need for a protective layer after the construction is completed. As long as the coating is completely cured, it will not be afraid of knocks, hits, collisions, peeling and wear. It can be used for construction at any time on water-seeping or flooded base surfaces. For newly built or under-construction concrete base surfaces, it can be used at the same time during the curing period (when the water has not completely evaporated). It is simpler if the dry spreading method is used for base plate construction.

 

Common construction methods for cement-based penetrating crystalline waterproof coatings

 

There are three main construction methods commonly used for cement-based penetrating crystalline waterproofing materials: scraping construction method, brushing construction method, and dry spreading construction method.

 

Scratching construction method:

 

The scraping construction method refers to a construction method that uses plastering to scrape the mixed cement-based permeable crystalline waterproof material slurry onto the base surface that needs to be waterproofed.

 

The construction of cement-based penetrating crystalline waterproof coating should be carried out according to the steps of points, seams, and surfaces, that is, the leaking points and seams should be dealt with first, and then the large-area coating construction should be carried out.

 

The preparation of mortar for scraping construction method is the key. Use clean water to mix the materials. The mortar should be mixed evenly without any dry lumps or powder balls. The mixed slurry should be used up within half an hour.

 

During construction, apply the prepared slurry evenly on the base surface that needs to be waterproofed with a plastering iron plate or plastic scraper as required. Before waterproofing construction on old structures, the original waterproof coating must be removed. There must be no floating dust or oil stains. Any uneven or damaged structures must be leveled and repaired. The dry base surface should be sprayed with water to moisten it first. If there are any spots and seams with water seepage, the water seepage areas should be sealed first.

 

When constructing on the front surface, the amount can be slightly increased to maximize the anti-seepage ability of the waterproof coating; when constructing on the back surface, even small leaks are easy to detect, and the leakage can be plugged first during waterproofing construction.

 

Brushing construction method:

(1) Preparation of mortar for brushing method: Generally, it is required to add 2 to 3 parts of materials to 1 part of water and stir until it becomes a thick paste. The mixed slurry must be able to be painted to a certain thickness.

 

(2) Before waterproofing construction on old structures, the original waterproof coating must be removed. There must be no floating dust or oil stains. Any uneven or damaged structures must be leveled and repaired. The dry base surface should be sprayed with water to moisten it first. If there are any spots and seams with water seepage, the water seepage areas should be sealed first.

 

(3) Construction requirements: Two or more coatings are required to complete. During construction, attention must be paid to the cleaning of the coating base surface, but there is no need to do too much moistening treatment. The coating exposed to the sun can be moistened and cured with clean water for 1 to 2 days.

 

Dry spreading construction method:

Construction is carried out after the concrete is poured, vibrated, compacted, and leveled (before the concrete is completely set). Sprinkle the specified amount evenly on the concrete surface, compact and smooth in time. If it is exposed to the sun, it should be sprayed with water and maintained for 1 to 2 days.

 

Cement-based permeable crystalline waterproof materials have gradually become one of the main materials for underground concrete structure waterproofing projects due to their superior waterproof performance, simple construction, reasonable overall cost, environmental protection, and non-toxicity.