DIN CEN/TS 15963*DIN SPEC 1026:2010-05

The Notched Three Point Bending test is used to measure fracture properties of unmodified and modified bituminous binder samples. The test sample is a beam with a notch in the middle of one side of the beam. The sample is conditioned in a temperature controlled bath. The beam is placed on two supports with the notch facing downwards and a vertical downward force is applied on the middle of the upper face of the sample. The beam is loaded until failure with a specified displacement rate, whereby the required force is recorded vs. the displacement.The advantages of the proposed test method, compared to other existing methods, are the followings.- This method allows determining an intrinsic property linked to the stress needed for crack propagation (KIC: critical tenacity or critical stress intensity factor).- Numerous publications have shown that this type of test (inspired by fracture mechanics) allows discriminating between binders contrary to other tests like BBR (EN 14771) or H2 tension test (EN 13587).- A special attention has been held to the notch design. Indeed, a 2 layer PTFE film is inserted during the moulding process in order to have a reproducible 50 micrometer thick notch.