There are two methods to calculate the prestress losses: AASHTO or Manual. Select the AASHTO method to input the release time in days (for LRFD) or hours (for LFD), and specify the relative humidity percentage. Select Manual to input the release and final loss percentages. Click OK to accept modifications or Cancel to ignore the changes and return to the Beam tab.

Click Relative Humidity to view a map of Mean Relative Humidity % for the United States.

Figure Design Parameters - Prestress Losses: