Ein praxisgerechtes Messverfahren zur Bestimmung der Fasermenge und -orientierung im Stahlfaserbeton

A practice-conform measurement method for determination of fiber dosage and orientation in steel fiber reinforced concrete

Steel fiber reinforced concrete (FRC) is versatilely and increasingly used in civil engineering, e. g. for industrial floorings and in industrial, tunnel and housing building segments. The characteristics and performance of steel fiber reinforced concrete is primarily determined by dosage, distribution and orientation of fibers in the concrete texture. For an effective determination and assessment of these parameters in fresh and hardened concrete a fast, simple and practicable non-destructive measurement technique is required. For this purpose the steel fiber measuring device "BSM100" at the iBMB/MPA of the TU Braunschweig in collaboration with the company Hertz Systemtechnik GmbH Delmenhorst had been developed. This is based upon an induction measurement system, where a cubic or cylindrical concrete sample in a coiled sensor is exposed to an alternating magnetic field. By registering the measured induction voltage the average values of dosage and three dimensional distribution of steel fibers in a fresh or hardened concrete sample can be investigated reliably and precisely.
In this contribution firstly the state of the art technology for the measurement of steel fiber dosage and orientation in concrete will be presented. Then the measurement device "BSM100" with its functional principle, actual research results and previous findings will be presented and several examples of practical use will be shown.