This International Standard specifies a method for the determination of the modulus of rupture of dense and insulating shaped refractory products at ambient temperature, under conditions of a constant rate of increase of stress. The method relates primarily to shaped and fired refractories. If it is to be applied to chemically bonded or tar-bonded bricks, they will usually require some form of preliminary heat treatment.This preliminary treatment, the details of which are outside the scope of this standard, is a matter of agreement between the interested parties and is described in the test report.