Title: Strength of Concrete T-Beam Bridges

Author(s): David B. Beal

Publication: Symposium Paper

Volume: 88

Issue:

Appears on pages(s): 143-164

Keywords: bridges (structures); deterioration; evaluation; field tests; loads (forces); load tests (structural); reinforced con-crete; strength; T-beams

DOI: 10.14359/6263

Date: 11/1/1985

Abstract:
A series of static live load tests were performed on two concrete T-beam bridges to evaluate stress induced in tension reinforcement and transverse load distribution factors. The purpose of these tests was to evaluate the usefulness of service load testing in evaluating the load carrying capacity of concrete bridges. The two structures were similar in dimension and reinforcing but had concrete of markedly different quality as determined from deck cores and sonic pulse velocity measurements through the deck and beam stems. The load test results showed no difference in bridge behavior attributable to concrete condition. To obtain data on failure capacity, testing was performed on two single and one double T segment taken from the deteriorated struc-ture. Rebar stress, centerline displacement, and end rotation were measured during the loading program which culminated in com-pression failure after rebar yield. The measured failure moments exceeded the nominal flexural strength as given by ordinary ulti-mate strength design methods. The consequences of these findings on the load rating process are discussed and a strategy for rating older reinforced concrete T-beam bridges is proposed.