In order to play a leading role in innovation, the Ministry of housing and urban rural development organized the preparation and issuance of the technical guide for urban rail transit engineering innovation (hereinafter referred to as the "guide"). The guide contains ten innovative technologies of urban rail transit engineering, including open excavation, mining, shield tunneling, waterproofing, groundwater control, crossing engineering, equipment installation and joint commissioning, survey and monitoring, detection, green construction, information construction and management. In the aspect of waterproof technology, polyethylene polypropylene waterproof roll composite waterproof technology, high polymer roll pre laying anti sticking waterproof technology, spraying quick setting rubber asphalt waterproof coating construction technology, concrete crack resistance and anti-seepage technology, high-performance waterproof and anti-corrosion material leakage treatment technology, variable joint leakage treatment technology, GIS + BIM application technology in the quality management of waterproof engineering, welding type Eight construction technologies of polymer pre laid waterproof roll are selected. The Ministry of housing and urban rural development requires all departments of housing and urban rural development to do a good job in promoting and applying the guide in combination with the actual situation.
Construction technology of spraying quick setting rubber asphalt waterproof coating
Background of Technology
When the subway open excavation station is supported by the hanging wall rock socketed pile (hanging foot pile), the retaining pile is set in the upper part of the foundation pit, and the anchor cable support is set, and the shotcrete hanging net support is used in the lower part of the foundation pit. First of all, the waterproof layer of the side wall has changed from "external waterproof and internal sticking method" to "external waterproof and external sticking method". Generally, two kinds of different waterproof materials need to be used for the conventional external waterproof, and the principle of waterproof is that the same station material should be as single as possible, so as to avoid the overlapping of different waterproof materials to become the weak link of waterproof; secondly, the coating is the first choice for the post sticking method construction, with strong bonding with the base surface and no overlapping joint The waterproof integrity is good, but the puncture resistance of conventional coating is poor, and it is easy to be damaged in the cross construction site. In order to solve the above problems, a kind of material and technology that can well bond with the concrete, can pre lay and anti stick and post cast concrete tightly, has strong puncture resistance, has certain self-healing performance, and has good compatibility with other waterproof materials, simple and reliable construction, energy saving and environmental protection is needed.
Technical content
(1) Material characteristics of spraying quick setting rubber asphalt waterproof coating
The high elastic waterproof and anticorrosive materials are produced by the reaction of the modified emulsified asphalt of ultra-fine suspension anionic microemulsion and the synthetic polymer with the special solidified substance. The main waterproof mechanism is that a variety of polymer materials in modified asphalt form a coating film on the surface of ultra-fine asphalt molecules, and form a continuous network from these molecules wrapped by polymer, and cross-linking through each other, so that the modified asphalt shows high polymer performance. After the coating is dry and film-forming, it maintains the high elasticity, low temperature flexibility and aging resistance of rubber materials It has the advantages of strong puncture resistance, no overlapping, no water channeling, high temperature resistance, frost resistance, chemical corrosion resistance, crack resistance, cold construction, self extinguishing and flame retardant, non-toxic, no peculiar smell, no environmental pollution, etc.; at the same time, the rubber film formed by these polymers has a small gap width between molecules, which prevents the penetration of water molecules in nature, so as to achieve the effect of waterproof and anti leakage.
(2) Construction application
1) When the quick setting rubber asphalt waterproof material is used as the waterproof layer, the whole seamless coating waterproof layer can be formed on the structural base surface by the direct spraying process. The waterproof material is a two-component coating, the main agent a of the waterproof coating is a brown viscous liquid, and the curing agent B is a colorless transparent liquid, which is sprayed by a special spray gun, and the two components meet in the air, mix and fall to the ground to form a film, forming a complete rubber waterproof layer; 2) there is a pile protection section at the bottom of the foundation pit, which is overlapped with the polymer waterproof coiled material pre laid on the bottom plate, and the transition is simple and dense If the second formwork is used to pave the waterproof layer first, it can be pasted tightly with the later pouring concrete; 3) the side wall waterproofing of the upper sloping excavation part can be done at the same time with the roof, which is fast, so as to prevent the secondary construction from increasing the finished product protection; 4) the coating thickness is 2.0-2.5mm, which can be sprayed once, and the surface can be dried for a few minutes; the construction period is short and the weather resistance is strong.
Main technical performance and technical characteristics
(1) Excellent physical properties 1) Extensibility: the average elongation at break of waterproof coating can reach more than 1000%, and the recovery rate can reach more than 90%. It is especially suitable for the expansion joints of subway stations, and can effectively solve the problems of leakage and corrosion caused by stress deformation, expansion cracking, puncture, or poor connection of various structures; 2) mechanical puncture resistance: the unique hydrophobicity of waterproof coating The self-healing function of the coating is created by the combination of cyan component and the three-dimensional mesh structure with memory function and high resilience polymer material, which can repair the puncture occurred in the early construction and later use of the subway station without leakage; 3) adhesiveness: the adhesiveness of the waterproof coating to the concrete structure of the subway station has reached 0.7MPa, realizing the whole waterproof layer of the subway station The seamless and skin type waterproof layer does not peel off and does not fall off. It plays a good protective role for the structure. 4) weatherability: the coating has strong anti-aging ability, and the accelerated aging test reaches 8000h, which improves the service life of the waterproof layer, reduces the use cost of waterproof products, and improves the performance price ratio of the product.
(2) Construction process performance
1) Energy saving and environmental protection: the waterproof coating does not contain volatile organic compounds, is non-toxic and tasteless, has no waste materials, has no waste gas emission, and has no pollution in the process of raw material procurement, production, storage, transportation, sales, construction and use; at the same time, during the whole construction process, there is no need for heating, no open fire, and normal temperature construction, greatly enhancing the safety and reliability of construction; 2) complete package Coating: the coating can completely cover the base surface of the structure, realize the seamless bonding between the coating and the base, so as to realize the characteristics of no water channeling and no peeling. Liquid storage, normal temperature spraying, good thixotropy, more convenient construction; 3) high construction efficiency: special spraying equipment is used, normal temperature spraying construction, film can be formed after 4 s spraying, can be trampled, one-time spraying can reach the design thickness, save labor, and can greatly shorten the construction period, reduce the construction cost; 4) low requirements for base surface: construction can be carried out on the surface of wet substrate, and the surface of substrate can be The surface treatment is also simpler, so that the quick setting rubber asphalt waterproof coating can be applied on any working base surface without open water.
Application scope and application conditions
It is suitable for the external waterproof layer of underground engineering of rail transit, especially for the external waterproof layer of underground structure which needs the conversion of "external prevention and internal sticking" and "external prevention and external sticking" when the form of hanging pile type enclosure structure and the upper part of enclosure pile is soil nail or sloping, and it can also be used for the external waterproof layer of other underground structure engineering. The base surface shall be flat, and the construction interface shall be free of open water. For the construction of external prevention and internal sticking method, 0.5mmhdpe can be constructed first and then the coating can be sprayed.
Applied
Tianjin Metro Line 6 cultural center station, Changsha Metro Line 4 hanwangling Park Station, Qingdao Metro Line 1 haipoqiao station, Xiamen Metro Line 1 Xiamen north station, Tianshui Road station, yuanboyuan section, etc., Xiamen Metro Line 2 financial center station, Linjin shaft section, Gaolin station, etc., have achieved good waterproof effect.
Detailed introduction of spraying quick setting rubber asphalt waterproof coating
1 product introduction
1.1 product composition and performance
Spray fast curing rubber asphalt waterproofing coating is made up of A component of rubber asphalt emulsion and B component of demulsifier. A component is composed of anionic high solid content emulsified asphalt and anionic neoprene latex, styrene butadiene latex and other polymers, and water polymer is formed by blending modification. After a and B components are mixed by special spraying equipment on site, they are quickly demulsified and solidified to form a dense, continuous and complete film layer with high elongation, super elasticity, excellent durability and waterproof, anti-corrosion, anti-seepage and protective functions. The product can be constructed on the wet base surface. The curing speed is fast, the gel time is not more than ten seconds, and it can be sprayed to the thickness of 2mm above once, and the construction speed is fast and environmental protection. The product has the following characteristics:
1) Ultra high elasticity: the elongation at break of the coating can reach more than 1000%, which is suitable for expansion joints and deformation joints. It can effectively solve the problems of leakage and corrosion caused by stress deformation, expansion cracking, puncture or poor connection of various structures. It can effectively deal with structural deformation and ensure the waterproof effect.
2) Overall waterproof: the coating can perfectly cover the base layer and realize the seamless connection of the coating, so as to meet the requirements of no water channeling and no peeling which are difficult to be realized by the coiled material. It is more simple and reliable for the base construction with special structure or complex shape.
3) Strong puncture resistance: the reticular structure formed by rubber in the coating is compact, and has super high elongation, so it has good puncture resistance, which is suitable for the parts easy to be punctured.
4) Self sealing and self-healing: high elasticity and high elongation make the self-healing function of the coating film. The general puncture can be repaired by itself without leakage.
5) Excellent chemical resistance and temperature resistance: the coating has excellent chemical corrosion resistance, acid, alkali, salt and chlorine resistance, high temperature and low temperature resistance.
6) Mechanical construction: after mechanical spraying, it will take shape instantly, and professional spraying machinery will be used for construction, which can greatly save construction cost and labor force, and greatly shorten construction period.
7) Flexible and diverse construction methods: in addition to spraying construction methods, painting methods such as brushing and scraping can also be used to meet the special requirements for water-proof operations such as water outlets, internal and external corners, construction joints, structural cracks, etc.
8) It can be constructed on wet surface: it can be constructed on wet and no open water base, which is convenient for application in subway, tunnel, water conservancy and other engineering fields.
9) Water based, environmental friendly and energy-saving: as a new generation of energy-saving and environmental friendly water material, in the process of production, construction and use, no organic solvent, cold refrigeration spray, non-toxic and tasteless, no exhaust emissions, no pollution. During the whole construction process, there is no need for heating, normal temperature construction and open fire, which ensures the safety and reliability of construction.
1.2 current situation at home and abroad
1) Foreign situation:
Spraying quick setting rubber asphalt waterproof coating is called liquid rubber in foreign countries. It was invented by radina company in 1993, and then the technology has been popularized all over the world. With the increasing requirements of the international market for the environmental protection, construction convenience and waterproof effectiveness of waterproof materials, and the products meet the future mainstream trend of the global waterproof market, so at present, such products are being widely promoted and applied in North America, Europe, Russia and the Middle East. Now the United States, Canada, Russia, Israel, Belgium, South Korea, Thailand and the Middle East have the production and application of this product. Spray quick setting rubber asphalt waterproof coating as a main auxiliary waterproof material, in the United States and Canada, the product has thousands of tons of application every year.
2) Domestic situation:
This technology was first introduced by Tianjin Bolier Technology Development Co., Ltd. from Canada in 2007; Ningbo radina Coating Technology Co., Ltd. and Dayu Weiye (Beijing) International Technology Co., Ltd. from America and South Korea in 2008; Ningbo Xinling waterproof materials Co., Ltd. and Dalian meichente environmental protection and energy saving products Co., Ltd. started in 2009 Research and development, production of the raw product; subsequently, many waterproof manufacturers are optimistic about the product, have begun to enter the field. Now there are Shenyang Guojian Jingcai, Beijing Jianhai Zhongjian, Beijing feitu, Beijing Zhongfang Weiye, Shandong beichuangxin, Henan Tiandi waterproof, Beijing Dongfang Yuhong, Guangdong Keshun, Tangshan Desheng, Tian