Figure 4: Concrete Rebound Hammer correlation curves
Reading your Results
Make at least ten readings from a concrete surface and discard the highest and
lowest rebound numbers. Average the remaining eight numbers. If desired, take
a few test readings before you complete your series of ten regular tests. Use the
average rebound number to estimate the strength of the concrete. Compare
your average rebound number to the chart shown on your Concrete Rebound
Hammer. Consider the diagram shown here:
Rebound Number
Correlation curves. This diagram shows the relationship between the
compressive strength for concrete, measured directly in a laboratory using
concrete cylinders or concrete cubes, and the rebound numbers you receive
using your Rebound Hammer.
A
refers to using the Rebound Hammer against a concrete floor (downward).
B
refers to using it against a concrete wall (forward).
C
refers to using it against a concrete ceiling (upward).
