Using and choosing a curing method for prestressed concrete members involves several factors. The most important factor is internal concrete temperature. Because of this, external heat is usually applied to produce the 3000- to 6000-psi compressive strengths typically required for detensioning prestressed concrete products after 12 to 18 hours of curing.
Temperature is critical to meeting the dual concerns of higher early strength concrete or reduced curing time. Once the proper materials and mix proportions have been selected, prestressed concrete producers can use several techniques to apply heat. Since this production phase is critical in determining the cost of curing, it is worthwhile to review the basics of accelerated curing.