This utility model discloses a rebound hammer for non-
destructive testing of UHPC
compressive strength, belonging to the field of concrete
engineering testing technology. It includes a hollow shell, an
impact rod, an
impact hammer, an
impact spring, a guide rod, a hook
assembly, and a switch. The impact rod is telescopically connected to one end of the shell. One end of the impact spring is fixed, and the other end is connected to the
impact hammer. Both the
impact hammer and the hook
assembly are slidably connected to the guide rod. The hook
assembly can slide along the guide rod and engage with the
impact hammer. The switch controls the release of the impact hammer by the hook assembly. The free length of the impact spring is 134.4±0.5mm, and the impact length after stretching is 140.0±0.5mm. The wire
diameter of the impact spring is greater than 1.5mm. The UHPC
compressive strength regression equation is: ; the value of c ranges from -0.001 to -0.004, where is the average rebound value of the test area or specimen, is the average
carbonation depth of the test area, and is the converted value of concrete strength in MPa. This enables non-
destructive testing of the
compressive strength of UHPC.