Page 56 - 2018 DIGITAL BROCHURE

SHOTCRETE AS90

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 to Once setting has started DO NOT
surface in advance to provide an cement ratio of 38% should be attempt to remix or to smooth the
adequate key. It should be clean, aimed for. Exceeding this ratio will surface. This will cause the
free from dust and thoroughly lead to lower strength, longer mechanical properties in particular
dampened. Where necessary steel setting time and the risk of surface strength and adhesion to be lost.
or aluminium mesh can be used. cracking appearing. Do not premix SHOTCRETE AS90
Ensure that a 10mm minimum SHOTCRETE AS90 should be with water before placing in the
thickness of material is obtained. added to the dry spray shotcrete dry spray machine. Protect the
machine and transported by dry surface of the SHOTCRETE AS90
Priming air to the nozzle where the water is from directsunlight or wind until
There is no need to prime any added. To obtain low dust levels, setting has completed.
reinforcement, but if priming is better and more consistent mixing Once the SHOTCRETE AS90 has
preferred, any conventional qualities, it is advisable that the set allow at least 1 hour before
system may be used. water is added to the applying any finishes.
SHOTCRETE AS90 approximately Carry out the removal of all loose
1.5 metres from the end of the material from the concrete and
nozzle. In cold weather the set reinforcement. It is only necessary
can be accelerated using warm to remove rust from the
water, likewise in hot weather cold reinforcement. Prepare the surface
water can be used to slow down as described previously, ensuring
the set. the surface is well dampened but
also ensuring there is no standing
water. Fix any necessary
reinforcement, movement joints
and formwork.
Add the dry SHOTCRETE AS90
powder continuously to the dry
spray applicator machine with the
water being added and controlled
at the nozzle ensuring that the
SHOTCRETE AS90 is worked
around any reinforcement.