AASHTO HBSLD-1

This guide specification is intended to offer design recommendations for agencies wishing to implement service life design principles and detailing recommendations. It was developed to incorporate quantitative approaches, along with proven deemed-to-satisfy provisions, into a single comprehensive design document for implementation on a national level. It also establishes a framework for service life design, while providing opportunities for refinement and expansion, especially as new models capable of simulating deterioration mechanisms become available.

Recent shifts in expectations regarding long-term performance of bridges have focused attention on the design of bridges to meet specific service lives. This has resulted in a call to expand traditional limit states to include a focus on durability in addition to the strength design and serviceability requirements already contained in the AASHTO LRFD Bridge Design Specifications. In North American structural design codes, durability-focused limit states are not explicitly identified and are addressed primarily through deemed-to-satisfy requirements. Over the last few decades, research has been conducted to identify specific durability limit states and to develop rational and quantitative approaches to consider them during the design phase. This guide specification is a product of the efforts of NCHRP 12-108 and includes the service life guidance contained in a number of AASHTO, FHWA, NCHRP, Strategic Highway Research Program 2 (SHRP2), and other national and state-sponsored research documents.