PCE Instruments PCE-HT-75-ICA Schmidt hammer Calibrated to (ISO standards) 0.735 J, 0.735 Nm Building material/concrete

The low-force concrete test hammer works according to the principle of Schmidt. In addition to the essential use in the construction and construction sector, the easy-to-use low-force concrete test hammer is also used in many other industries for purposes other than intended use (winding hardness testing of products on a roll, ...).

The test is carried out under an always equal impact energy of 0.735 J. The initial kinetic rebound energy is specified as a measure of concrete hardness / surface pressure or compressive strength (kg/cm² or converted to N/mm²) on the low-force concrete test hammer. The quality of concrete is mainly assessed by its compressive strength, as it is directly decisive for the bearing behavior and durability of concrete constructions. The low-force concrete testing hammer brings a significantly lower impact energy on the concrete, which is why it is particularly suitable for testing thin-walled elements up to a material thickness of 100 mm.

Compressive strength is indicated by a series of letters and numbers. Example: B 25 means that this is normal concrete with a compressive strength of 25 N/mm². There are various intermediate values up to the highest strength class B 55, so you can easily, quickly and accurately classify using the low-force concrete testing hammer. The low-force concrete test hammer is always delivered in the factory calibrated when ordered, but can also be laboratory calibrated and equipped with an ISO test certificate/test certificate as an option (at an additional cost).

General information on pressure resistance measurement of concrete using the low-force concrete test hammer
Compressive strength is generally understood as breaking strength measured under single-axis, short-term pressure load. The compressive strength of the concrete is mainly determined by the following influencing factors:

- The strength of the cement stone
- Composition and compaction of concrete
- Age and storage conditions
- Body shape and dimensions
- Type and duration of loading

The pressure resistance is determined in the lab using concrete cubes or circular cylinders. For cylinders, it is recommended to apply the leveling layer, which is usually required to obtain a flat and smooth upper pressure surface, immediately after the coating of the excess concrete. Cylinders should be hardened vertically. Since in practice a hardness test according to laboratory method cannot be performed, the low-force concrete test hammer is used here which is easy to handle and relatively accurate. The pressure resistance is determined by measuring the material hardness using the low-force concrete test hammer (rebound value R) on the surface of the concrete and by means of the conversion table (on the rear of the device) or taken from the table in the operating instructions.

This text is machine translated.