Is it cheaper to build concrete swimming pools by shotcreting or by casting in place?
In the three methods commonly used for concrete pool construction (shotcrete, precast, and cast-in-place), it is necessary that the horizontal reinforcement carry the horizontal tensile forces caused by the pressure of water within the pool. This reinforcement is usually used at 12,000 to 15,000 psi. When steel is stressed much higher than this in tension, the likelihood is increased that tensile cracks will form. Shotcreting provides a liner to rest against the embankment which provides horizontal support. This kind of construction is not considered the most suitable where the embankment is not stable or where external hydraulic pressure is possible. Where facilities for precasting are available, precast construction offers the possibility of economies through reduction of forming and labor. When joints are properly designed and constructed, this type can perform as well structurally as can cast-in-place structures. Cast-in-place construction is generally chosen where embankment shifting or external pressures due to other causes are possible. Cast-in-place walls are designed as flexural members with the steel stresses mentioned above. This type is also chosen in some areas for reasons of economy. Relative costs between cast-in-place concrete and shotcrete vary widely but in general shotcrete is cheaper.