Introduction：
      DH-821 elastic waterproof material is a polyurea elastomer material composed of isocyanate semi-prepolymer, aromatic amine chain extender, polyether, pigment and additives. It is  a new type of "green and environmentally friendly" spraying technology that adopts new equipment and new process to spray on the spot. It is one of the most advanced spraying technologies in the world at present.

Purpose：
      DH-821 elastic waterproof material is mainly used for roof waterproofing, waterproofing of concrete structures about reservoirs, swimming pool, aquariums, tunnels, dams, bridges and water conservancy projects. It is also used for waterproofing of high-speed railway concrete precast bridges.

Performance indicators:

Solid content	100%
Gel time	10 seconds
Tensile strength	≥15MPa
Tear strength	≥50KN/m
Elongation at break	400%
Hardness, Shore A	75 ~ 95
Bond strength,MPa	≥2.5
Water tightness	0.4mpa,2h water tightness
low temperature flexibility (-40 ℃ )	no fracture
Color	various colors are adjustable
Density,g/cm3	1.02
Recommended thickness	1 -- 2mm

Substrate processing：
      The concrete substrate should be removed the cement floating slurry, and loosed impurities on the substrate, ensure the substrate  should be clean before construction, avoid oil and impurities, avoid water on the substrate, repair cavity defects, and brush concrete special sealing primer.

The coating method：
      High temperature and high pressure spraying equipment specially used for polyurea are used for substrate.

Supporting materials：
      DH-XN repair putty was used to repair the holes and defects on the concrete substrate.
      Apply a special concrete seal primer DH-DQ003 to the substrate.
      During multi-pass spraying, if the interval between each passes is so long that it can exceed 3 hours, the surface need to be polished, and then DH-DQ001 layer adhesives are applied.
      If the polyurea material is damaged, manual repair material DH-X200 can be used.