NORTH CAROLINA.
FREEZE-THAW AND
SALT AIR.
Two climates, one state. As coal plants closed, Class F fly ash, long used in mixes to reduce the risk of ASR, got scarce, and the cement itself shifted toward Type IL. Same product names on the ticket. This is not about anyone's bad faith. There was no requirement anywhere in the chain to document that the chemistry had changed. Not on the batch ticket. Not in the contract. Not at the pour. This page sets out the two exposures North Carolina concrete sees, and what a PSIP record holds on a North Carolina pour.
Freeze-thaw in the Piedmont. Salt-air on the Outer Banks.
North Carolina concrete sees two distinct climate-driven exposure profiles. The Piedmont and the western mountains operate under freeze-thaw cycling. The Outer Banks and the coastal counties operate under salt-air and sustained Atlantic humidity. Both profiles affect mix-design durability planning.
Freeze-thaw cycling
ACI 318 exposure class typically requires air-entrained mix designs and durability planning for the freeze-thaw vector.
Salt-air corrosion
Sustained relative humidity from Atlantic coast climate, chloride-driven corrosion exposure profile, ASR-relevant moisture conditions.
PSIP does not say which exposure is worse, or what a mix for either should be. On a concrete job, a PSIP record holds the region and the pour day conditions. On a pool, it holds the conditions at the shell before the shoot. PSIP never said what they had to be.
Dual climate. Documented pour.
On a concrete pour, a PSIP record holds the specified mix design, the cement type, and the supplementary cementitious material by type, or that none is specified, as the contractor states them at setup, before placement. On a pool shell, it holds the batch tickets for each shoot day, the delivery method, wet shotcrete or dry gunite, and the nozzle operator by name, as the builder states it. Every batch ticket is photographed, and the photograph records what the ticket shows. Tickets vary, and many do not list everything in the load, so the contractor adds what he knows in the notes, as his own statement. PSIP records the work and certifies that it was recorded. The contractor is responsible for local building codes, permits and licensing. PSIP certification is not an inspection, a code approval or a warranty. No material supplier can pay for a say in PSIP, and PSIP does not recommend products.