Four-point flexural test

This difference is of prime importance when studying brittle materials, where the number and severity of flaws exposed to the maximum stress is directly related to the flexural strength and crack initiation.

[1] The four-point bending test is therefore particularly suitable for brittle materials that cannot withstand shear stresses very well.

It is one of the most widely used apparatus to characterize fatigue and flexural stiffness of asphalt mixtures.

in these formulas the following parameters are used: Advantages of three-point and four-point bending tests over uniaxial tensile tests include: Disadvantages include: Ceramics are usually very brittle, and their flexural strength depends on both their inherent toughness and the size and severity of flaws.

Exposing a large volume of material to the maximum stress will reduce the measured flexural strength because it increases the likelihood of having cracks reaching critical length at a given applied load.

Values for the flexural strength measured with four-point bending will be significantly lower than with three-point bending.,[7] Compared with three-point bending test, this method is more suitable for strength evaluation of butt joint specimens.