China's Longest Tunnel - Qinling Zhongnanshan Highway Tunnel [1]
Introduction of Waterproof Slab for Highway Engineering
Waterproof slab is a kind of anti-seepage material made of macromolecule polymer, which can prevent both liquid leakage and gas volatilization. It is widely used in construction, transportation, subway, tunnel and engineering construction.[2]
Functions of Waterproof Slab for Highway Engineering
The main function of waterproofing slab is to prevent the leakage of liquid and volatilization of gas. The function of waterproofing slab in rock engineering is mainly to prevent seepage and isolation, but it also plays a role of strengthening and protecting. It is mainly used in earth-rock dam, rockfill dam, masonry dam, concrete dam, tailings dam, sewage reservoir dam, channel, reservoir and other engineering seepage prevention, subway, basement and tunnel seepage prevention lining, highway and railway foundation seepage prevention, bentonite waterproof blanket and other geotechnical materials.[3]
Why did we choose EVA Waterproof Slab for Highway Engineering
At present, the basic waterproof slab used in expressway construction is EVA (vinyl acetate copolymer) resin as the main raw material, adding certain fillers, plasticizers, anti-aging agents, ultraviolet absorbents and other auxiliary materials, which are made by drawing, extrusion and other processes. EVA resin is a copolymer of ethylene and vinyl acetate. The content of vinyl acetate (VA) is 5%-40%.
EVA polymer composite self-adhesive waterproofing membrane has excellent impermeability, high puncture resistance, high barrier, low temperature flexibility, super physical properties, aging resistance, chemical corrosion resistance, easy welding, and can be constructed at very low site temperature.[5]
Testing items and standards
Mandatory testing items: Tensile strength, elongation, tear strength, impermeability, low temperature flexure resistance, hot gas aging, alkali resistance, appearance quality, appearance size.
Select test items: Artificial Climate Aging, Bond Peeling Strength, Ozone Aging, Heating Expansion.[8]
Table1: Mandatory testing items and standards of EVA water-proof slab.[9]
References
[1]: The Longest Tunnel in China-Qinling Zhongnanshan Highway Tunnel, Available at: http://wemedia.ifeng.com/46427872/wemedia.shtml (Accessed on 05.19.2019)
[2], [3], [5]: TB/T 3360.1-2014, Water-proof materials used in railway tunnel, Part1: Water proof slab, obtained from Shaanxi Provincial Expressway Construction Group Company
[4]: Image of EVA Tunnel Waterproof Plate, Available at: http://www.youboy.com/s74812766.html (Accessed on 05.19.2019)
[6]: Kingsun waterproofing(2010-2017), Available at: http://www.kswaterproof.com/eva-waterproof.html [17 May,2019]
[7]:Polyfill LLC(15 Aug. 2014), Filled EVA Barrier Safety Data Sheet, Available at: http://www.polyfillproducts.com/EVA-SDS.pdf [Assessed 17 May,2019]
[8], [9]: GB 18173.1-2012, Polymer water-proof materials, Part 1: Water-proof sheet, obtained from Shaanxi Provincial Expressway Construction Group Company