We're building an outdoor basketball court that will be flooded in the winter and used as an ice skating rink. What can we do to protect the concrete from damage caused by freezing?
This exposure isn't as severe as subjecting the concrete to deicing chemicals, which increase the number of freeze-thaw cycles. However, you should take the same approach that is used to produce a durable concrete driveway. Order a 4000-psi air-entrained concrete with a 3- to 5-inch slump, and specify an air content of 5% to 8% for 3_4- or 1-inch maximum-size aggregate. Also specify chert-free coarse aggregate if it's available. Don't start finishing until bleeding has stopped and the water sheen on the surface has disappeared. If a troweled surface is required, it's especially important to delay troweling until bleeding has stopped. This avoids trapping bleedwater beneath a surface sealed by troweling. Moist cure the concrete at least three days, then allow the surface to dry for at least 30 days before it's exposed to freezing.