Straight from the definitions in Chapter 1 of AASHTO LRFD: Design Life - Period of time on which the statistical derivation of transient loads is based: 75 years for these Specifications. Commentary of Section 1.3.2.1: The Strength I Limit State in the AASHTO LRFD Design Specifications has been...
AASHTO LRFD Bridge Design Specifications(SI unit 9th edition 2020)© 2020 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.