A proposal for a beam end type bond test: procedures and preliminary results

A beam-end test is proposed to verify that existing provisions for bond and anchorage in the fib Model Code may also be used for structural design when non-conventional concretes are adopted (i.e. Fibre Reinforced Concrete-FRC, Recycled Aggregate Concrete-RCA, etc.). This test method is intended to determine the effects of concrete type and casting position on the anchorage strength of reinforcing bars. Two bars are cast in each specimen (in the two opposite corners), one in a 'good' casting position and the other in 'poor' casting position. Performance of the bar anchorage would be assessed against several measures, namely peak bar stress, bar stress at loaded end slips of 0.05 mm (crack control, tension stiffening) and at unloaded end slips of 0.02 mm (stiffness), free end slip at peak load, and the individual curves of force-slip relations. In the paper the preliminary test results of 16 mm rebars having anchorage length of 20 times the bar diameter in plain concrete and in non-conventional concrete (FRC and RAC), will be presented. Experimental results provide information both on the “top cast effect” and on the effectiveness of fib Model Code provisions for anchorage when non-conventional concrete is used.