A brief introduction of the new EVA processing material EVA waterproof foam board

    How to distinguish the performance of EVA waterproof foam board, ECB waterproof board and PE waterproof board?

    At present, the polymer coils commonly used in waterproof and anti-seepage projects mainly include PVC (polyvinyl chloride), ECB (ethylene-vinyl acetate and asphalt copolymer), EVA (ethylene-vinyl acetate copolymer), LDPE (low density polyethylene) ) And HDPE (High Density Polyethylene).

    PVC performance is relatively poor and has not been used in tunnel waterproofing, so this standard does not require them; among them, HDPE has high strength but high hardness, and is rarely used in tunnel waterproofing; EVA coils, the exact name should be EVA modified PE coils are mainly modified with EVA. The amount of EVA is generally 20%~50%, but it is still called EVA coils. After EVA modified PE, the flexibility and elongation of the coil will be greatly improved.

    Waterproof board product width specification: the larger the width of the waterproof board, the fewer welded joints, which is more conducive to ensuring the quality of the waterproof project. However, when the width is too large, the weight of the waterproof board will become difficult to construct, so the waterproofing specified in this standard The board width specifications are 2.0, 3.0 and 4.0, and users can choose by themselves according to construction needs. Product testing items and physical and mechanical performance indicators: When determining the inspection items and physical and mechanical performance indicators of the waterproof board, the main basis is TB10003 "Railway Tunnel Design Specification", and refer to GB 18173.1 "Polymer Waterproof Material Partial Sheet". It also requires good puncture resistance, durability, water resistance, impermeability, corrosion resistance, and bacteria resistance. EVA manufacturer

    Product thickness specification: The thickness specification specified in GB18173.1 is 0.5 mm or more, and the thickness specification specified in TB 10003 should not be less than 1.2mm. However, it is difficult to ensure the quality of the waterproof board for tunnel waterproofing and is rarely used. . For tunnel waterproofing in Europe, a 3mm waterproof board is used when there is water pressure, and a 2mm waterproof board is used when there is no water pressure; a 3 mm protective board is spot welded on the inverted waterproof board, and a waterproof board is generally installed in the reinforced concrete lining. Layer to prevent the waterproof board from being damaged during construction. The material of the protective layer is basically the same as the waterproof board. Taiwan’s Pinglin High-speed Railway Tunnel has a total length of 6.5km and a head of 80m. Due to environmental factors, it adopts all-inclusive waterproofing. The waterproof design adopts German standards. The waterproof board adopts 2.5mm thick LDPE and the geotextile adopts 700 g/m2 non-woven polypropylene; A 1.7 mm thick HDPE layer is laid on the waterproof board at the invert position to prevent subsequent construction from damaging the waterproof board. Therefore, from the perspective of ensuring the quality and reliability of waterproofing projects, the thickness of the waterproof board specified in this standard is 1.5, 2.0, 2.5, and 3.0.