An important member of building waterproofing materials, chemical grouting materials

1 Important members of building waterproofing materials Chemical grouting materials, also known as waterproofing pulp, are equivalent to waterproofing membranes, waterproof coatings, waterproof putty or clay, rubber-plastic waterstops or metal waterstops. The difference is that the chemical grouting material has the following characteristics: 1 It is a solution, and it is a true solution, never layering, no precipitation; 2 very low viscosity, some pulps are even close to water; 3 curing or gelling Time can be artificially controlled; 4 pump can be used to inject cracks, fill cracks, block leakage water, have the function of repairing water stop structure in situ or constructing anti-seepage curtain separately, especially suitable for underground concealed works; 5 volume during solidification or gelation The shrinkage is small; 6 the cured product or the gel itself does not seep; 7 the cured product or gel has good durability. The above features and functions are not available or can not be replaced by building waterproof materials. For this reason, chemical grouting materials have special importance in waterproof engineering and become an indispensable member of building waterproofing materials. 2 Classification of commonly used grouting materials At present, the chemical grouting materials commonly used in China are roughly divided into two categories according to their performance and use. There are six major series and hundreds of branded products. The first category is anti-seepage and water-stopping, including four series of water glass, acrylate, polyurethane and lignin pulp. The second category is reinforcement and reinforcement, including two series of epoxy resin and methyl methacrylate pulp. Among them, water glass pulp can be divided into two major types: alkaline and acid. Polyurethane pulp can be divided into oil-soluble, water-soluble and elastic. Epoxy resin can be divided into non-reactive diluent and active dilution. Three major varieties of agents and furan resin. It must be pointed out that the water glass slurry in the first type can also be used for reinforcement and reinforcement engineering, but the strength is low; the epoxy resin material in the second type can also be used for anti-seepage and water-stopping projects, but the unit price is high. . The brands and R&D units of epoxy resin and polyurethane pulp with large domestic consumption are listed in Tables 1 and 2.

Table 1 Domestic common epoxy pulp brand and research and development unit

3 Main uses and application departments Due to the above seven characteristics of chemical grouting materials, chemical grouting materials and technologies are particularly suitable for plugging and water stopping, curtain anti-seepage, foundation reinforcement and crack repair in engineering construction. From the current point of view, the application fields of chemical grouting are mainly in the four industries of hydropower, construction, mining and transportation. The specific application fields are as follows: 1 foundation dam, reservoir, culvert and other foundation anti-seepage curtains and foundation reinforcement; 2 levees, channels, Anti-seepage, plugging and reinforcement of aqueducts, etc.; closed water and seepage prevention and foundation reinforcement of 3 nuclear power plants; 4 anti-seepage, plugging and water-stopping, foundation reinforcement and crack repair of underground buildings (such as subway, civil air defense, tunnels, etc.) Strong reinforcement; 5 anti-seepage curtains for interception projects such as mines, factories' toxic wastes, waste water and municipal garbage dumps; 6 water inrush and leakage treatment in mine construction and re-grouting for weak stratum reinforcement and stabilization; 7 oil drilling In the case of plugging and stopping water, drilling wall reinforcement and oil displacement; 8 bridge foundation reinforcement and bridge crack reinforcement; 9 weak ground reinforcement of the airport and apron, special road and railway sections, anti-seepage and concrete crack reinforcement ; 10 Rivers and harbors port construction (such as docks, ship locks, breakwaters, etc.) for foundation seepage and reinforcement.

Table 2 domestic commonly used polyurethane pulp brand and research and development unit

4 Application of domestic grouting materials Although chemical grouting materials are small varieties in waterproof materials, with the development of China's infrastructure construction, the application volume is increasing year by year, and the annual dosage has exceeded 10,000 tons. According to the rough statistics of 12 units in eight cities along the coast in 2004, the amount reached 6 635 t, as shown in Table 3.

Table 3 12 companies or companies in eight coastal cities

Rough statistics of the amount of pulp used in 2004

In different application fields, the application of chemical grouting materials also varies according to engineering requirements, and the choices are also different. For example, the underground construction industry and the subway building are mostly made of polyurethane pulp; the mining department stops the water and the transportation department repairs the roadbed and chooses the cheap water glass pulp; the hydropower department builds the dam to use the acrylate as the anti-seepage curtain and the epoxy pulp. The material is used to reinforce the dam foundation; the cultural relics protection department uses methyl methacrylate pulp to repair the cultural relics. The application of chemical grouting materials in large-scale projects is very large, such as the repair of leakage accidents in the first phase of the Gezhouba Hydropower Station, and the use of elastic polyurethane pulp for more than 20 tons; the collapse of the Shanghai Metro Line 4 Only one water-stop polyurethane pulp material can reach 102 t; in the past few years, the Three Gorges Project has applied more than 570 tons of chemical grouting materials for seepage prevention and foundation reinforcement (see Table 4); a chemical irrigation enterprise in Guangdong last year only In the roadbed reinforcement and anti-seepage of the Gui, Yue and Xiang highway repair projects, more than 2 000 t of water glass pulp was used.

Table 4 Overview of the application of the Three Gorges Engineering Grouting Materials

5 Overview of Domestic Grouting Materials China's chemical grouting industry was initiated after the founding of New China. After more than 50 years of development, it has achieved remarkable results. This is also closely related to a number of industrial departments and some colleges and universities have trained a group of researchers engaged in chemical grouting technology. With the development of China's infrastructure construction, the application of waterproofing grouting materials has increased year by year, and the research on the development and application of pulp materials is gradually increasing. In the past five years, there are about 323 research papers on chemical grouting in sci-tech journals and magazines, of which 240 are research and application of pulp materials (see Table 5).

Table 5 Overview of the research and application of domestically produced grouting materials in the past 5 years

It can be seen from Table 5 that, from the order of the number of research papers, the first three are epoxy resin pulp, polyurethane pulp and water glass pulp, but in practice, the opposite is true, water glass pulp is more than polyurethane pulp, and Polyurethane pulp is more than epoxy resin. The level of results obtained from research and application is also high. The results of chemical grouting in the Three Gorges Project are examples. The project has reached the international advanced level in the following three aspects: 1. Applying the non-toxic acryl slurry developed in China to replace the toxic and carcinogenic C-gel slurry, the first dam chemical anti-seepage curtain net; 2 CW epoxy pulp and cement - chemical compound grouting technology to reinforce the weak muddy fault fracture zone; 3 use five layers of anti-seepage and water-stopping measures including chemical pulp to treat a number of concrete joints on the water surface of the sluice gate . Among them, the high-head concrete seam treatment of the Three Gorges Project has always been the focus of attention of Chinese and foreign media. 6 Chemical grouting materials and environmental protection chemical materials often contain some toxic compounds. Chemical grouting materials used for waterproofing are no exception. Therefore, personnel who research and apply grouting materials must improve their environmental awareness and prevent pollution. . The author has accumulated years of experience in research and application of waterproofing grouting materials. The following four principles for selecting and applying anti-pollution in the grouting material are proposed: (1) The grouting material can be used to solve the problem of anti-seepage and reinforcement of the project; 2 Under the premise of meeting the basic requirements of engineering waterproofing, the selected grouting material should be selected. It is preferred to use water-free glass pulp without environmental pollution; 3 use other waterproofing grouting materials should choose pollution-free products, and be careful not to expand the application range and dosage arbitrarily; 4 It is recommended to disable and disable the chemical grouting materials containing toxic compounds, as soon as possible Look for alternatives. For example, a propylene condensate slurry composed mainly of acrylamide, an epoxy syrup with furfural as a diluent, a urea-formaldehyde resin slurry containing formaldehyde as a main component, etc., which contain acrylamide and formaldehyde, are carcinogenic, and furfural It is harmful to the nerve center of human beings and has been officially listed by the relevant UN organizations in the list of 12 banned and restricted compounds. The above three types of pulp should be prohibited or restricted. Chemical grouting materials have become an indispensable member of building waterproofing materials due to their unique and excellent properties. Its research, production and application in China are constantly developing. The application of chemical grouting materials should pay attention to environmental protection. It is believed that the future application prospects of chemical grouting materials in China's hydropower, transportation, construction, mining and other industries must be very broad.  

Metal Sheet Laser Cutting Machine is professional in cutting varies metal sheets. Such as stainless steel, carbon steel, mild steel, iron, galvanized steel, titanium steel, silicon steel, brass, aluminum, titanium alloy, brass, copper, silver, gold, etc.  

Metal Sheet Laser Cutting Machine advantage:  

1. Efficient and stable programming and control system, easy to learn and user-friendly, compatible with a variety of CAD drawing formats, intelligent nesting to save costs, automatic cutting path matching to save processing time;                      2. Metal Sheet Laser Cutting Machine with low energy consumption and low cost of use; high equipment stability, simple and convenient maintenance, and low maintenance cost;

3. No need for molds, flexible processing, can meet the processing requirements of various shaped workpieces
Metal sheet laser cutting machine with high cutting efficiency, high cutting quality, no noise; high speed, high efficiency, cutting sheet can reach tens of meters per minute; cutting edge quality is good, deformation is small, appearance is flat and beautiful;
4. Japan's Yaskawa high-precision servo motor greatly improves the operation stability and reliability of the equipment while ensuring the processing efficiency and processing accuracy;

Metal Sheet Laser Cutting Machine

Ss Plate Cutting Machine,Laser Metal Cutting Machine,Laser Cutting Machine,Metal Cutting Machine

Jinan Huaxia Machinery Equipment CO.,Ltd , http://www.cnformingmachine.com