PoolQ To keep shrinkage cracking sufficiently tight so as not to cause reflective cracking in the plaster layer, what is the proper depth of reinforcing steel from the shotcrete surface in swimming pool applications?
This question should be addressed by a qualified engineer with experience in designing swimming pools and well-versed in shotcrete technology. Shotcrete is a method of placing concrete and the parameters that work for concrete cover work for shotcrete.
Good practices for placing shotcrete or concrete include:
- Predampening the soil that the concrete/shotcrete is placed against;
- Ensuring that the reinforcing bar temperature is not too high; and
- Early curing of the shotcrete surface and maintenance of curing for the specified duration. If no duration is specified, a 7-day wet cure is recommended.
Using fibers in the shotcrete/concrete can also help control surface early-age plastic shrinkage cracking.
