Thermocouple data from an instrumented prestressed concrete segmental bridge (North Halawa Valley Viaduct) have been efficiently reduced graphically to determine the critical positive and negative thermal gradient. The results are compared with those recommended by various AASHTO specifications. A simplification to the computation procedure for the analysis of segmental bridges for nonlinear thermal gradient is proposed. A fully worked numerical design example is included to demonstrate how the analysis is greatly simplified, and to discuss the impact of the design thermal gradient on the prestressing requirements.
