IIBCC 2010, Aarlborg
Dr. Ulrich Mörschel, Erich Ingelsberger
Textechno Herbert Stein GmbH & Co. KG,
Mönchengladbach/Germany
ABSTRACT
Manufacturers generally add fibres for cement reinforcement in short-cut form, typically about 6 mm long. To control the quality of the reinforced cement in an early stage, the tensile properties of the fibres need to be monitored.
Testing short-cut fibres is very challenging. Fibre producers usually supply an uncut tow segment for testing. However, this method risks mix-ups and ignores fibre stress damage caused by cutting. This paper presents a new approach using a single-fibre tensile tester with specially designed clamps, enabling precise measurement of tensile properties even in short-cut fibres.
A special software algorithm corrects the inherent error in elongation measurement, ensuring accurate results for modulus and breaking elongation. For uncut long filaments, the instrument measures tensile properties and linear density using the proven vibroscopic principle. Since linear density relates to the fibre’s effective cross-section, the instrument directly determines breaking tension (e.g., in MPa). Leading PVA and PP fibre producers worldwide already use both the standard and automated versions.
Finally, for further tests on the uncut filament, the instrument can be equipped with wrap-bollard clamps to measure even coarse and highest-tenacity fibres, and with a special device to measure the friction along an individual fibre, which makes the instrument outstandingly suitable for tests on PVA reinforcement fibres.
Back to Overview