Coating standard: cement based permeable crystalline waterproof material and its standard

The key points are as follows: 1 Development and application of cement-based permeable crystalline waterproof materials The cement-based permeable crystalline waterproof material is a kind of product made of Portland cement or ordinary portland cement, quartz sand and other base materials, mixed with active chemicals It is a new type of rigid waterproof material The mechanism of its action is that after its interaction with water, the active chemicals contained in the material penetrate into the concrete through the carrier, forming water-insoluble crystals in the concrete, and filling capillary channels, so as to make the concrete dense and waterproof The cement-based permeable crystalline waterproof material is Germany Paint knowledge | precautions for wall paint color selection Recommended introduction: when painting the wall, the owner sometimes has difficulty in choosing what color of the wall paint to paint In fact, there is no ugly color in the wall paint, only the disharmonious color matching The use of wall color contains the knowledge of health Too strong color will stimulate people's perception, make people have a sense of fidgety, affect people's mental health Grasp the basic principles of wall color and paint a colorful space 1、 Wall paint color selection notice 1 Light color is generally used for the top surface Light colors make people feel light, dark colors make people feel heavy Usually, the treatment of rooms is from top to bottom, from shallow to deep For example, the ceiling and walls of rooms are white and Coating home news: first, the development and application of cement-based permeable crystalline waterproofing material is a product made of Portland cement or ordinary portland cement, quartz sand and other base materials, mixed with active chemicals, which is a new type of rigid waterproof material The mechanism of its action is that after its interaction with water, the active chemicals contained in the material penetrate into the concrete through the carrier, forming water-insoluble crystals in the concrete, and filling capillary channels, so as to make the concrete dense and waterproof The cement-based permeable crystalline waterproof material was invented by the German chemist laritz Jensen in 1942 It is mainly used for the outer surface waterproof of underground concrete structure In the mid-1960s, it was introduced to North America from Europe, and spread to Canada in 1966 Toronto International Trade Building, Calgary City, Canada's oil headquarters "internal waterproofing", Canada's sewage treatment plant, domestic water storage tank, etc all use this waterproof material Because of its good impermeability and self-healing performance, strong adhesive force, corrosion prevention of steel bars, harmless to human body, easy to construction, etc., it has been widely used in Europe, the United States, Japan, Singapore and other countries and regions, mainly used in underground engineering, water conservancy engineering, water pool, sewage treatment and other structural waterproofing, and has achieved good waterproof effect In 1980s, China introduced cement-based permeable crystalline waterproof materials and began to apply them to Shanghai Metro project In the mid-1990s, active chemicals (masterbatch) were introduced from abroad for domestic production At present, the annual design and production capacity is estimated to be about 13000 tons, which has been widely used in underground engineering, subway engineering, drinking water plant, sewage treatment pool, bridge deck, tunnel, water conservancy engineering, nuclear power station, etc the waterproof effect is remarkable and is well received by the engineering community 2、 According to the use of cement-based permeable crystalline waterproof materials, the performance and action mechanism of cement-based permeable crystalline waterproof materials can be divided into: 1) Cement based permeable crystalline waterproof coating: it is a kind of powder material, which can be mixed with water to prepare slurry for brushing or spraying on the surface of cement concrete; it can also be spread with dry powder and pressed into the surface of cement concrete that is not completely set 2) Cement based permeable crystalline waterproof agent: it is a kind of powder material mixed into concrete The coating thickness of cement-based permeable crystalline waterproof coating is generally in the range of 0.5-1.5mm according to foreign data, and it should not be less than 0.8mm according to Chinese specifications As long as there is water medium and calcium hydroxide in the base cement concrete, the active chemical substances in the coating may continuously have physical and chemical effects with it, generate crystals, and expand to 0.3 mm, that is, the maximum size higher than the capillary diameter of the concrete (usually 0.01 mm), block the capillary channels and micro cracks, and form a whole waterproof together with the base concrete The reaction between the chemical active substances in the cement-based permeable crystalline waterproof coating and the water in the concrete base and the calcium hydroxide can last for one month and reach the highest effect At 16 MPa, ordinary concrete can penetrate to 150 mm; at 40 MPa, the penetration depth of silica fume concrete in 9 weeks may be less than 25 mm The activity and penetration depth of cement-based permeable crystalline waterproof materials depend on the content of active chemicals in the materials, the compactness of the base concrete, water content, calcium hydroxide concentration and the temperature and humidity of the surrounding environment Different from other organic or inorganic waterproof coatings, the cement-based permeable crystalline waterproof coating forms an integral part with the base concrete, forming a whole waterproof and permanent waterproof, rather than only forming a "coat" Although the coating and the base concrete are bonded together, they are still "two skins", which will be separated under the effect of external environment for a long time 3、 Brief introduction to the technical requirements of the national standard for cement-based permeable crystalline waterproof materials there is no product standard for cement-based permeable crystalline waterproof materials abroad, only the product manual and some test data of the manufacturer, mainly including the impermeability pressure, compressive strength, setting time, etc In order to ensure the product quality and meet the needs of the project, the domestic production enterprises have formulated the enterprise standards of the company's products However, in the enterprise standard, there are few technical indicators, inconsistent test methods, and regional limitations, which affect the promotion and use of this new waterproof material in China Therefore, it is very necessary and significant for enterprises to establish unified national product standards, organize production, effectively test and control product quality, so as to ensure the quality of waterproof engineering, and promote the promotion and use of this new product in a wider range of our country With the approval of the General Administration of quality supervision, inspection and Quarantine of the people's Republic of China, the compulsory national standard GB 18445-2001 "cement based permeable crystalline waterproof materials" was formally implemented on March 1, 2002 The following is only a brief description of "requirements" in the standard 1 Homogeneity index this index is an important index reflecting the quality management level and product quality stability of production enterprises Each production enterprise shall, according to the requirements of waterproof engineering, the raw material status, production and management level of the enterprise, stipulate the production control value of the factory in the enterprise standard, and control the fluctuation of the production control value within the index range specified in the standard The production control value of the factory shall be informed to the user in the product specification of the enterprise The factory inspection report shall report the measured values of homogeneity index to the user, and the products exceeding the standard cannot be delivered Water content: generally, cement-based permeable crystalline waterproof materials are supplied to users in powder form Therefore, the level of water content will affect the storage and use performance of products Therefore, this standard stipulates that each production enterprise should be controlled within 5% of the control value of the plant Total alkali content: the alkali aggregate reaction leads to the damage of concrete The alkali in concrete is mainly brought in by cement, aggregate, admixture, etc Therefore, the total alkali content of products (Na2O + 0.658k2o) is strictly regulated within 5% of the control value, which can improve the durability of buildings and structures Chloride ion content: in consideration of the corrosion effect of chloride ion on steel bars, this standard stipulates that the project shall be controlled within 5% of the relative control value of the manufacturer Fineness: because the fineness of the admixture varies greatly among the production enterprises, but as a waterproof material, the fineness does not affect as much as the cement, so the standard does not stipulate the absolute value, but the production control value of the factory is stipulated by each factory The standard requires that the measured fineness (0.315 mm sieve) of the product should be controlled within 10% of the production control value of the factory The content of chloride ion and the homogeneity index of total alkali in the standard are the same as those in gb8076 and jc474 2 Setting time of the physical and mechanical properties of the cement-based permeable crystalline waterproof coating: the material is generally stirred in small batch, and the use amount of 20 minutes is appropriate According to the test and verification results of samples delivered by each plant, the initial setting time shall not be less than 20 minutes, and the final setting time shall not be more than 24 hours The initial setting time is too short to be coated, and the final setting time is too long to affect the construction period According to the test results, the compressive strength of the coating at 7 days and 28 days is 12.0 MPa and 18.0 MPa respectively, and the flexural strength at 7 days and 28 days is 2.8 MPa and 3.5 MPa respectively So that the design and construction departments can understand the mechanical properties of materials, and construct and maintain accurately Adhesive strength of wet base surface: the cement-based permeable crystalline waterproof coating is brushed or sprayed on the surface of cement concrete, infiltrated into the concrete according to * active chemicals, forming water-insoluble crystals, blocking capillary channels, making the concrete dense The coating and the base form a whole, achieving the purpose of impermeability and waterproof Therefore, the bond between the coating and the base concrete is very important, which is the necessary prerequisite to form the overall waterproof The standard stipulates that the bond force between the coating and the wet base surface must be greater than 1 MPa Impermeability pressure: it can be divided into upstream and downstream impermeability pressure Generally, waterproof materials are used for external waterproofing, only for upstream impermeability pressure; internal waterproof materials are used for downstream impermeability pressure The cement-based permeable crystalline waterproof coating can be used as internal waterproof or external waterproof According to the test results, there is a certain correlation between the seepage resistance pressure of the upstream and the downstream In order to reflect the characteristics of this material and reduce the test workload, the standard stipulates that the seepage resistance is measured by the downstream Impermeability pressure: type I 0.8 MPa, type II 1.2 MPa Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,