Rock bolts are used to stabilise rock excavations in mining, tunneling and civil engineering operations such as concrete dam reinforcements, road cuts and bridge abutments. A critical element to excavations of this kind is the surface stabilisation between rock bolts to hold unstable or fractured rock masses together. It is this required stability that is achieved by using Technicrete TSL (Thin Skin Liner), a modified polymer based fibre reinforced thin sprayed liner.
Technicrete TSL is supplied in easy-to-use kits consisting of a special liquid, which is a blend of powder chemicals and graded silica sand with polypropylene fibres.
The contents of the kit are simply emptied into a suitable mixer or pump which have a positive displacement type pump arrangement, then sprayed on to the cleaned rock face and into open joints and fissures covering all surfaces needing to be supported. Maximum penetration is obtained by spraying directly into any open joints. Compressed air is added at the nozzle to spray the fresh mix, whilst a seven metre delivery hose will deliver the best effect.
The bonding properties of Technicrete TSL bind the rock faces inside the fissures to provide a more stabilised rock surface and minimises the unravelling of rock mass. The tensile properties of Technicrete TSL spanning across joints and cracks resist shear and direct tensile movement adding to back pressure in the rock mass for added stabilisation.
In low stress environments the bonding and tensile strengths assist in preventing block movements, whilst keeping the rock ‘beam’ intact.
Benefits
Technicrete TSL can be:
- Rapidly deployed in underground environments as equipment is easy to handle in confined areas
- The sprayed-on support is quick to mix and hardens quickly
- Used as rock support for areal stabilisation of rock surfaces
- Stabilises friable ground
- Seals sensitive rock type such as smectite, shale, soft shales against water and humidity
- Prevents unravelling of fractured ground by holding key blocks in place
- Seals dams, sumps and drains
- A temporary areal support – prior to overcoating with shotcrete, which has a strong adhesion to Technicrete TSL
- Safely applied to damp substrates (but not onto surfaces covered in running water)
TSL EFNARC Specifications
Technicrete TSL has a shear strength of >0.25 MPa after 24 hours, a tensile strength of >2 MPa after seven days, an ultimate bond of shear 1.0 MPa and a bond strength of 1.0 Mpa. After the completed application simply flush the equipment thoroughly with water for cleaning. This process minimises pump and hose blockages.
