About Slotstress

Slotstress® is a technique that enables the direct measurement of in-situ concrete stress.

The strain relief method is proven to be the only reliable method available to measure stresses in concrete. Its principle is simple: the strain field is relieved by slotting the material; the change of the strain in the relieved area is measured and the stress is calculated taking into account the elastic properties of the material and the geometry of the cut.

However, in concrete, the modulus of elasticity varies with concrete mix, age, curing and environmental conditions. In order to eliminate the need to know the elastic properties of the concrete, a flat jack can be inserted into the slot and pressurized. As a result the initial strain field will be restored. The combination of the measured data on strain and pressure will give the value of the stress.