TRANSPORTATION RESEARCH DIGEST
ARIZONA TRANSPORTATION INSTITUTE
Survey of Current Practice for Design of High-Strength Concrete Prestressed Bridge Girders in Transportation Research Record 1892 by Mary Beth D. Hueste and Gladys G. Cuadros (Transportation Research Board, 2101 Constitution Avenue, N.W., Washington, D.C. 20418; ph. 202-334-2934; ) (2004).
Most of the DOTs have not made adjustments to the design specifications for HSC prestressed bridge girders.
The HSC prestressed girder types that are most popular among responding DOTs include the AASHTO beam, followed by the bulb beam and the box girder.
A survey titled Current Practice for Design of High-Strength Concrete Prestressed Members was developed and distributed to all 52 state departments of transportation (DOTs). The objective of this survey was to gather information and document critical aspects of current practice for the design of high-strength concrete (HSC) prestressed bridge girders. Responses were received during a 6-month period spanning from June through November 2002. This study is part of Texas Department of Transportation Research Project 0-210 I, Allowable Stresses and Resistance Factors for High-Strength Concrete.
The questionnaire consists of two parts. Part I, Current Design Practice for HSC Prestressed Bridge Members, contains 11 questions related to current specifications, additional documents and references, construction using HSC, typical range of specified concrete strengths at transfer and at service, concerns related to the use of HSC, and adjustments to the design specifications for HSC. Part 2, Description of Typical Bridges Using HSC Prestressed Bridge Members, provides information on the span lengths and
concrete strengths for a number of bridge types for which respondents have used HSC. Responses from 41 state DOTs were collected, giving a 79% response rate from this group. Respondents are listed in the reported results. Of the 41 state DOTs that provided a response, only 1 failed to give permission to identify its organization when reporting its response. This DOT is identified as "undisclosed DOT." Two Texas DOT (TxDOT) design offices were included in the survey: the Austin state office and the Houston district office. The following sections summarize the survey responses.
A survey was conducted to determine the current state of practice for the design of HSC prestressed bridge girders among departments of transportation (DOTs) in the United States. Of the 52 state DOTs in the United States, 41 provided a response. Responses were received during a 6-month period spanning from June through November 2002. Major findings are summarized below.
Adoption of the AASHTO LRFD Bridge Design Specifications by state DOTs is gradual. The AASHTO Standard Specifications for Highway Bridges, 16th edition, is the most popular code for bridge design in current practice. In most cases in which the LRFD specifications are used, implementation is partial; most states plan complete implementation between 2003 and 2007.
The responding state DOTs have a large variation in the number of new bridges constructed, with a range of 4 to 400 bridges per year.