GeneralQ We are looking at constructing climbing boulders made with shotcrete and using a polystyrene core. Does the polystyrene need to be covered with a protective membrane to protect it during the spraying process? Also, could the polystyrene contribute to the structural integrity of the boulders, or should it just be used as a void-forming material?
Polystyrene is available in various densities and the denser the product, the less likely that the shotcrete process will cause any damage to it. The question of the structural value of the polystyrene needs to be addressed by a competent structural engineer. It is not something that we, as a shotcrete association, feel qualified to comment on.
