Page 64 - 2018 DIGITAL BROCHURE
P. 64
SHOTCRETE 437F
Method of use Application
Preparing the surface Mixing General
Do not use on frozen or over For optimum results mix using A 10mm minimum thickness of
heated substrates (outside the conventional dry spray mixing the material is always necessary.
range of 0°c-30°c). Prepare the machines. The optimum water Once setting has started DO NOT
surface in advance to provide an to cement ratio of 38% should attempt to remix or to smooth
adequate key. It should be clean, be aimed for. Exceeding this the surface. This will cause the
free from dust and thoroughly ratio will lead to lower strength, mechanical properties in particular
dampened. Where necessary longer setting time and the risk strength and adhesion to be lost.
steel or aluminium mesh can be of surface cracking appearing. Do not premix SHOTCRETE 437F
used. Ensure that a 10mm SHOTCRETE 437F should be with water before placing in the
minimum thickness of material is added to the dry spray shotcrete dry spray machine. Protect the
obtained. machine and transported by dry surface of the SHOTCRETE 437F
air to the nozzle where the water from direct sunlight or wind until
Priming is added. To obtain low dust levels setting has completed. Once the
There is no need to prime any and better and more consistent SHOTCRETE 437F has set, allow
reinforcement, but if priming is mixing qualities it is advisable at least 1 hour before applying
preferred, any conventional that the water is added to the any finishes. Carry out the
system may be used. SHOTCRETE 437F approximately removal of all loose material from
1.5 metres from the end of the the concrete and reinforcement.
nozzle. In cold weather the set It is only necessary to remove
can be accelerated using warm rust from the reinforcement.
water, likewise in hot weather cold Prepare the surface as described
water can be used to slow down previously, ensuring the surface is
the set. well dampened but also ensuring
there is no standing water. Fix any
necessary reinforcement,
movement joints and formwork.
Add the dry SHOTCRETE 437F
powder continuously to the dry
spray applicator machine with the
water being added and controlled
at the nozzle ensuring that the
SHOTCRETE 437F is worked
around any reinforcement.
