MEYCO Equipment Division of BASF Construction Chemicals (Schweiz) AG Hegmattenstr. 24 CH-8404 Winterthur

MEYCO Penetration Needle Measuring Instrument

This indirect test method is specially designed to measure the early strength progress of shotcrete between 15 and 120 minutes average, depending upon grade of accelerator.

The MEYCO Penetration Needle is designed to cover the range from approximately 0,16 to 1,2 N/mm2, corresponding to green concrete shortly after the end of setting.

Operating principle This test method uses a needle with specific dimensions which is pushed with defined force and a defined distance into the fresh concrete. The resistance opposed and measured, readable on the MEYCO penetration needle, is taken as an indication of the concrete's compressive strength. To be precise, though, this method actually measures a combination of compressive and shearing strengths, or the resistance to local plastic deformations. The aggregates contained in the shotcrete and the support behaviour of the granulometry strongly affect the results.

For each measurement, the average of the 10 individual measurements is calculated. Depending on the maximum size of grain used, there are 2 calibration curves (for 8 and 16 mm) from which the compressive strength can be directly read. It is customary to test at 15', 30', 45', 60', 90'and 120'. Care must be taken not to push directly onto a large aggregate grain.

MEYCO Penetration Needle consists of: Hand measuring instrument made of stainless steel 3 testing needles stored in the handle 2 calibration curves for the most common grain sizes 0-8 mm and 0-16 mm

Usual operative range of the measuring techniques

Telephone: +41 58 958 27 00 / Fax: +41 58 958 37 07 / www.meyco.basf.com Subject to technical modifications!