Overload Behavior of 1/8th Scale Three-Span Continuous Prestressed Concrete Bridge Girders

摘要

This report describes the results of overload tests on two 1/8th scale prestressed concrete bridge girders. The three span continuous girders were made with three pretensioned I-section girders, and were made continuous for live loads by means of reinforcement in the composite cast-in-place deck. The structures were originally built as part of a study of the long-term behavior of prestressed concrete bridges. The structures were loaded with a model HS-type vehicle loading which was positioned to produce either high shears or approximately maximum moments in the various spans. The final tests produced very large deformations, and the maximum loads reached were in the range of 93 to 99 percent of the theoretical collapse loads. The behavior of the structures is described in terms of measured load-deflection and load-reaction curves, together with descriptions of the cracking that occurred as a result of the several loadings. Comparisons of measured and computed deflections, reactions, and cracking moments are made. The service-load deflections were generally smaller than expected, and the cracking moments larger than expected.