Adhesive and rheological properties of fresh fibre-reinforced mortars

Adhesive properties of fibre-reinforced joint mortars in fresh state are investigated using the probe tack test. This test consists of measuring the force required to separate at a given velocity two plates between which a thin layer of the tested material is inserted. The adhesive properties of the mortars, including cohesion and adherence to the plate surface, are inferred from the curves representing the evolution of the tack force versus instantaneous plate separation for different pulling velocities. The adhesive properties are qualitatively related to the rheological behaviour of the mortars. The latter are shown to behave as Herschel–Bulkley shear-thinning fluids. The influence of fibre content on both adhesive and rheological properties is investigated.