The Inductive Method is the first product of Smart Engineering Control ®
Smart Engineering launches Smart Engineering Control ®, a registered brand that encompasses a line of products for the assessment of material properties and structures. The Inductive Method is the first product on the market. It is a robust and simple non-destructive test to assess the content and distribution of steel fibres in fibre reinforced concrete (FRC). Smart Engineering has recently finishised the production of the first set of prototypes of the product and has started its commersialisation.
The equipment consist of an impedance analyser and a discontinuous coil with a cylindrical cross-section. Firstly, the impedance analyser generates an electric current flow, which in turn produces a magnetic field inside the coil. Given the ferromagnetic nature of the fibres, a sample inside the coil increases the magnetic permeability of the medium. As a result, the analyser measures the inductance variation inside the coil.
The test is designed for cubic or cylindrical specimens (size of 150 mm), which may be later used for mechanical characterisation through the Barcelona test (UNE 83515). The inductance of each sample is measured for the main directions perpendicular to the faces of the cubic specimens or in three axes in the cylindrical specimens. These measurements are sufficient to estimate the fibre content and orientation in the main axes. An additional measurement in the cylindrical specimens provides the orientation profile of the fibres.
This profile allows estimating the orientation number and the contribution of the fibres in other directions. The average error of the method for the fibre content is less than 0.4 kg/m3. Furthermore, the trueness and precision values for the orientation numbers are below 0.43 and 1.7%, respectively.
Major tunnel projects in Europe (e.g. Follo Line Project in Norway and Bank Station Capacity Upgrade Project in the UK) have implemented the Inductive Method as part of their quality control system with the support of Smart Engineering.