The classification and characteristics of waterproof coatings!
Waterproof coating is a general term for materials such as asphalt and polymeric synthetics that are taken As the main body, at room temperature for amorphous or semi-fluid, after coating can form a tough waterproof film on the surface of the structure.
1. Asphalt base waterproof coating
(1) cold base oil
Cold base oil is made of gasoline, kerosene, diesel fuel, industrial benzene and other organic solvents and asphalt material blended into a kind of asphalt coating. It has low viscosity and good fluidity. It can quickly penetrate into the capillaries of concrete, mortar, wood and other materials when applied on the substrate. Solvent evaporation will be firmly combined with the substrate, so that the surface of the substrate has a certain degree of hydrophobicity, creating favorable conditions for bonding similar waterproof materials. Because it is often used as a base material for room temperature waterproofing projects, so the name cold base oil.
Cold substrate oil formed by the coating film is thin, generally not alone as a waterproofing material, just as some waterproofing material support material. Construction, should be applied to the grass-roots level on the cold substrate oil, and then coated with asphalt waterproofing coatings or waterproofing materials. Cold primer can be used in conjunction with the preparation should use the same source of solvent as the asphalt. Usually 30% to 40% of No. 30 or No. 10 petroleum asphalt and 60% to 70% of organic solvents (mostly gasoline, diesel, kerosene, etc.) are used.
(2) Asphalt gum
Asphalt glue (also known as asphalt marsupial) is made by adding powder or fibrous filler (such as talc, limestone powder, dolomite powder, mica powder, wood fiber, etc.). It is injected into the melted asphalt and mixed them evenly. There are two kinds of cold use and hot use, the former is called cold asphalt glue or cold mastic, and the latter is called hot asphalt glue or hot mastic. Heat is generally used during construction. When preparing hot asphalt mastic, the asphalt is heated and dehydrated, and heated and dried powder or fibrous filler is hot mixed. The function of hot filler is to improve the heat resistance of asphalt, increase the toughness and reduce the low temperature brittleness. When cold, you need to add diluent dilution, to be applied at room temperature, coated into a uniform thin layer.
(3) Emulsified asphalt
Emulsified asphalt is an oil-in-water asphalt emulsion, through hot melt asphalt, high-speed mechanical shear, the asphalt in the form of particles dispersed in an aqueous solution containing emulsifier and formed. The dispersed system of asphalt as the dispersed phase, water as a continuous phase, at room temperature with good fluidity.
Emulsified asphalt has the following advantages.
1. Can be cold construction. Emulsified asphalt for road construction and other uses do not need to be heated. It can be mixed directly with the aggregate, or can be sprinkled or sprayed directly on the surface of the aggregate and other objects. Construction is easy, save energy, reduce pollution, improve labor conditions. Also reduces the number of times the asphalt is heated, and reduces the thermal aging of asphalt.
②Can enhance the adhesion of asphalt and aggregates and mixing uniformity, saving asphalt 10% ~ 20%.
③Construction season can be extended, the temperature in 5 ~ 10 ℃ can still be constructed.
④The application of asphalt can be expanded. In addition to being widely used in road projects, it is also used for waterproofing of building roofs and caves, corrosion protection of metal materials, improvement of agricultural soil and plant health, overall railroad bed, sand fixation in deserts, etc.
Emulsified asphalt should be packed in covered iron drums, plastic drums and woven bags, the storage temperature should not be lower than 0℃, avoid exposure to the sun. Storage period of 3 months from the date of delivery, the transport process shall not be tilted or placed horizontally.
2. Polymer modified asphalt waterproofing coating
Polymer modified asphalt waterproof coating, also known as rubber asphalt waterproof coating, is based on petroleum asphalt, modified by polymer waterproof coating. Recycled rubber is usually used for modification, or neoprene for modification. There are two types of this coating:water-emulsion and solvent-based.
Solvent-based recycled rubber asphalt waterproof coating, also known as recycled rubber asphalt waterproof coating, JG-1 rubber asphalt waterproof coating; solvent-based neoprene asphalt waterproof coating, also known as neoprene asphalt waterproof coating. Neoprene rubber asphalt waterproof coating is neoprene rubber and petroleum asphalt dissolved in methyl (or xylene) to form a mixed colloidal solution, its main film-forming substances are neoprene and petroleum asphalt.
Emulsion recycled rubber asphalt waterproof coating of the main film-forming substances are recycled rubber and petroleum asphalt; emulsion-type neoprene asphalt waterproof coating, also known as neoprene emulsion asphalt waterproof coating.
Solvent-based coatings can be in a variety of complex surfaces to form a seamless waterproof film, toughness and durability, film fast, good water resistance and corrosion resistance, can be used for room temperature or low temperature cold construction. However, a thin film, the use of gasoline or benzene as a solvent, in the production, storage, transportation and use of the process there is a risk of explosion. Neoprene is expensive and has high production costs.
Water-based coatings can form a seamless waterproof film on complex surfaces, with a certain degree of flexibility and durability, non-toxic and tasteless, non-combustible, safe and reliable, can be cold construction at room temperature, no environmental pollution, simple operation, easy maintenance, can be constructed on slightly wet surface, no water. However, repeated painting can meet the thickness requirements, poor stability, the temperature is below 5 ℃ should not be constructed.
3. Synthetic polymer coating.
Synthetic polymer coating is made of synthetic rubber or synthetic resin as the main film-forming substance, supplemented by other auxiliary materials. Synthetic polymer coating high strength, elongation, flexibility, high and low temperature, UV resistance, acid and alkali salt aging, long service life. Synthetic polymer waterproof coating according to the film-forming mechanism and solvent type can be divided into solvent-based, emulsion and reactive.
(1) polyurethane waterproofing coatings
Polyurethane (PU) waterproof coating, also known as polyurethane coated waterproofing materials, is a polyurethane resin as the main film-forming material polymer reactive waterproofing materials. This coating through the chemical reaction between the components directly from the liquid state into a solid, curing almost no volume shrinkage, easy to form a thick film. According to the composition can be divided into single component (S) and multi-component (M). According to the tensile properties can be divided into ⅰ, ⅱ two types, mostly used in the form of two-component. At present, there are two domestic, a tar series of two-component polyurethane coated waterproofing materials, a non-tar series of two-component polyurethane coated waterproofing materials.
Waterproof coating polyurethane elasticity, elongation, ozone resistance, weather resistance, corrosion resistance, wear resistance, non-combustible, simple construction operation. Brush 3 ~ 4 layers, the service life of more than 10 years. This type of coating is mainly used in high-grade building bathroom, kitchen bathroom, pool, basement waterproofing projects and roof waterproofing projects with a protective layer. Synthetic polymer waterproof coating performance is better than polymer modified asphalt waterproof coating, but more expensive. Can be used in conjunction with other waterproofing materials, with better overall waterproofing performance.
②Polymer cement waterproof coating
Cement waterproof coating, also known as JS composite waterproof coating, is a major category developed in recent years in the construction of waterproof coatings. It is acrylate, ethylene - vinyl acetate and other polymer emulsions and cement as the main raw material, add fillers and other additives, through the water volatilization and cement hydration reaction curing into a film and made of two-component water-based waterproof coating. Its performance is organic inorganic composite waterproof material. According to the mechanical properties can be divided into ⅰ type, ⅱ type and ⅲ type. I type is suitable for grass-roots units with high activity, II type and III type is suitable for grass-roots units with low activity.
The main technical properties of cement waterproof coating include tensile strength, elongation at break, bond strength, impermeability and resistance to permeation.
Polymeric waterproofing coatings are better adapted to the substrate. Can be used for wet base construction, the use of cement and water hydration reaction to eliminate the adverse effects of high moisture content of the grassroots. Has the advantages of fast drying speed, easy to operate shaped parts, construction process is safer.
4. waterproof coating storage, transportation and storage
Waterproof coating packaging containers must be sealed tightly, the surface of the container should be marked with the name of the paint, the name of the manufacturer, the date of production and product expiration date. Storage and storage of the ambient temperature shall not be lower than 0 ℃; prevent sunlight, collision and leakage; should be stored in dry, ventilated rooms, away from fire sources, warehouses should have special organic solvent fire prevention measures; transportation process, the wheels of the means of transport should be grounded to prevent static fire.