ABSTRACT
Shotcrete constructions of swimming pools and spas represents the largest area of use of shotcrete in North America, with some 9 million cubic metres of shotcrete reported to have been applied in 2008. Up until the 1950s nearly all swimming pools and spas constructed with shotcrete used the dry-mix shotcrete process. Dry-mix shotcrete is still used, but wet-mix shotcrete now dominates because of its greater rates of productivity and generally better control of quality of the applied shotcrete. This chapter examines the reason for this transition. There is also discussion of the American Shotcrete Association (ASA) Position statements regarding minimum performance requirements and cold joints in pools and spas, and the expectation that the shotcrete process should provide watertight structures. Case history examples are provided for three ASA award-winning pools; a residential vanishing edge swimming pool and spa complex built on a rock ledge in Connecticut, using the wet-mix shotcrete process; a vanishing edge swimming pool and spa complex built on a mountain slope in North Carolina, using the dry-mix shotcrete process, and finally, a 25-yard-long competition pool built at a high school in Connecticut using the wet-mix shotcrete process. All three of these pools were built as monolithic shells without joints and were demonstrated to be watertight, with no leakage when the shells were filled with water.
