... surface of concrete, its initial kinetic energ redistributes, a part of energy in the form of plastic deformation or ... deformation is adsorbed by the concrete, and another part of energy which is proportional to the surface ... the impact hammer, making the hammer resile to a certain height, then the strength of the concrete ... 8045, EN 12504-2, ENV 206, DIN 1048 part 2, ASTM C 805, ASTM D 5873, NFP ...