CYCLIC LOAD TESTS OF COMPOSITE PRESTRESSED-REINFORCED CONCRETE PANELS

STATIC AND CYCLIC LOAD TESTS MADE ON SEVEN COMPOSITE PANELS OF PRESTRESSED CONCRETE AND CAST-IN-PLACE CONCRETE ARE DESCRIBED. THE PRESTRESSED PANELS ARE USED AS STAY-IN- PLACE FORMS FOR CONCRETE BRIDGE DECKS. REINFORCED CONCRETE BONDS TO THE TOP SURFACE OF THE PRESTRESSED PANELS AND THE UNIT ACTS COMPOSITELY UNDER TRAFFIC LOADS. SOME OF THE TEST PANELS CONTAINED AN INTERLOCKING SHEAR LUG WHICH WAS CAST IN THE PRESTRESSED PANEL AND WAS ENGAGED BY THE CAST-IN-PLACE CONCRETE. OTHERS HAD NO SUCH LUGS. PANELS WITH THE SHEAR LUGS SHOWED A SLIGHT ADVANTAGE IN STIFFNESS OVER THE OTHERS AT HIGH LOADS. ONE PANEL WITH SHEAR LUGS WAS CYCLED UNDER 210 PERCENT OF DESIGN LOAD FOR 11.9 MILLION LOAD CYCLES WITHOUT FAILURE. ONE PANEL WITHOUT SHEAR LUGS REACHED FAILURE DEFLECTION OF 1/4 IN. AT 2.25 MILLION CYCLES UNDER 210 PERCENT OF DESIGN LOAD. /AUTHOR/