MASTERSEAL 845A 

MASTERSEAL 845A is a one-component polymer powder for spray-application onto soil and rock.  The product is mixed with water in the spraying nozzle to hit the substrate in the form of a paste.  The product sets within 5-10 minutes (tack free) and will generate tensile strength and bond strength over the next hours, days and weeks.  Through good bond to most substrates, high elasticity and high tensile strength the ground stability and stand-up time is substantially improved.

Sprayed concrete can be applied against the membrane as soon as it has set and the typical bond strength concrete to membrane will be more than 1.0 Mpa.

In civil tunneling and mining the product can be used for:

• Stabilization of soil and rock
• Rock reinforcement in areas with difficult accessibility
• An alternative to mesh/screen protection, with or without bolts
• Preliminary per-round support allowing later sprayed concrete application on a larger area giving improved efficiency.
• Preliminary slope protection binding the surface before the area is ready for sprayed concrete
• Against hard-rock strain bursting
• When large deformations are expected 
• To reduce air-slacking and rock weathering
• Pillar/rib support
• Rehabilitation of collapsed areas
• Immediately after TBM cutter head in tunnelling operations
• Can also be used for vent stopping