BONDING BEHAVIOUR OF REINFORCING STEELS UNDER CONTINUOUS LOADING IN BOTH NORMAL AND LIGHTWEIGHT CONCRETE

VERBUNDVERHALTEN VON BEWEHRUNGSSTAEHLEN UNTER DAUERBELASTUNG IM NORMAL- UND LEICHTBETON (V 155)

TESTS HAVE SHOWN THAT THE BOND BEHAVIOUR OF STEEL IN CONCRETE MAY BE CONSIDERABLY IMPAIRED BY CONTINUOUS LOADING OR BY MULTIPLE LOADING AND UNLOADING. THERE ARE NO RESULTS OF TESTS AVAILABLE. IN ORDER TO DERIVE BASIC LAWS ON BONDING FOR NORMAL AND LIGHTWEIGHT CONCRETE, (INCLUDING THE INFLUENCE OF TIME), THE INFLUENCE OF DEPTH OF RIBS, DISTANCE BETWEEN RIBS, DEGREE OF ROUGHNESS OF THE STEEL SURFACE AND CONCRETE STRENGTH IS TO BE STUDIED ON BARS WITH DEFINED RIBBED SURFACES (RIBS PRODUCED BY MILLING OF SMOOTH BARS) UNDER CONTINUOUS AND UNDER REPEATED LOADING AND UNLOADING BOTH IN NORMAL CONCRETE AND IN LIGHTWEIGHT CONCRETE.