题名: |
Improved Connection Details for Adjacent Prestressed Bridge Beams. |
作者: |
Roberts-Wollmann, C.; Cousins, T.; Halbe, K.; Field, C. |
关键词: |
Bridges, Prestressed concrete beams, Splice lengths, Reccommendations, Conventional concrete, Connections (joints), Voided slabs, Pre-stressed girders, Pre-stressing steel, Reinforcing steel bars, Corrosion alloys, Cracking agents, Ultra-High Performance Concrete (UHPC) |
摘要: |
Bridge with adjacent box beams and voided slabs are simply and rapidly constructed, and are well suited to short to medium spans. The traditional connection between the adjacent members is a shear key filled with a conventional non-shrink grout. With time and traffic, many of the joints show signs of cracking and leaking, and eventually, corrosion of the reinforcing and prestressing steel within the beams. The overarching goal of the project was to develop an improved detail for the connection between adjacent members using Ultra-High Performance Concrete (UHPC) or Very High Performance Concrete (VHPC). The specific objective of the research presented in the report was to determine the appropriate splice length for No. 4 and No. 6 uncoated reinforcing bars used in a UHPC or VHPC connection. A total of 15 beams were tested to determine the appropriate splice lengths for uncoated No.4 and No. 6 bars in UHPC and VHPC. The 12 inch tall by 10 inch wide by 8.5 feet beams were precast with conventional concret4e, with a block-out pocket to accommodate a splice. The tension bars were spliced in the pocket, which was then filled with either VHPC or UHPC. The beams were tested to place the splice location in a region of constant moment, and were loaded monotonically to failure. It was found that for an uncoated No. 4 bar in UHPC or VHPC a splice length of 4 inches is inadequate to develop the yield strength of the bar, but a length of 5 inches is recommended to insure ductility. For a No. 6 bar in UHPC a splice length of 5 inches is adequate to develop the yield strength, but 6 inches is recommended to insure ductility. |
总页数: |
Roberts-Wollmann, C.; Cousins, T.; Halbe, K.; Field, C. |
报告类型: |
科技报告 |