Live load testing and load rating of five reinforced concrete bridges.

PDFTech ReportME 14-1320130102*2462Reinforced concrete bridgesLive loadsLoad testsRatingsMaineMaine. Dept. of TransportationGoslin, KeenanDavids, BillUniversity of Maine. Advanced Structures and Composites CenterUS Transportation CollectionFive cast-in-place concrete T-beam bridges \ue2\u20ac\u201c Eustis #5341, Whitefield #3831, Cambridge #3291, Eddington #5107,and Albion #2832 \ue2\u20ac\u201c were live load tested. Revised load ratings were computed either using test data or detailedanalysis when possible. In four of the five bridges, increases in rating factors were made through analysis alone. TheCambridge bridge was shown to have HL-93 operating rating factors greater than 1.0 for both shear and momentwithout testing. Additionally, gains are presented for two of the five bridges (Eustis and Whitefield) where testdata was used to compute an adjustment factor K for midspan bending, where the revised rating factor equals K xRF. Adjustment factors were found to be 1.61 and 1.24 for Eustis and Whitefield, increasing their flexural ratingfactors to 1.14 and 1.06 if accepted by the Maine DOT. Similarly, our analyses indicate that Eustis has a ratingcapacity greater than 1.0 for shear. While Whitefield has a rating factor greater than 1.0 for shear at the supports, therating factor for shear near the termination of the bent-up reinforcing is 0.48 based on our analyses.Low loads used in the live load tests of both Albion and Eddington, where only one truck was provided on site,preclude the development of revised rating factors based on the test data. However, both of these structures didexhibit better-than-expected live load distribution. Further, analysis of the Albion bridge indicates that theconsultant-provided load ratings for this structure can likely be increased significantly.Use of these revised load ratings, live load test data, and extrapolation of these results to other structures is at thesole discretion of the bridge owner.The objective of this study, to implement an effective live load testing bridge program, was fulfille