Ada Schmidt Hammer 225 А00191 [28/36] Schmidt hammer 225

MEASUREMENT FOUNDATION

Schmidt Hammer 225

3. Rebound operation

Follow the operation abovp-mentioned and to continue pushing and press the Test Hammer until the rebound hammer

and hook was disengaged and under the stretched actoin of strike tension spring, strike hammer along the center guide

rod impact quickly, kinetic energy will decomposition of hammer and rod in the moment of collision : a part of the energy

to produce plastic deformation of concrete have been absorbed, the other part so that produces elastic deformation of

concrete transfer to sreike hammer to rebound.

Operation reading the rebound values

“ When the strike hammer and rod collision for the rst time rebound, will pointer slide into a certain position (through the

spring plate), then should continue to hold down the Test Hammer, and reading rebound values Ri from the slider scale

mark corresponding to the pointer ruler scale line ; if the inconvenience to reading, can press the button and lock the

machine, the movement to retain the slider pointer position, and then get the Test hammer to the place ease of reading

rebound values. The above is a rebound test operation process, which get the rebound value Ri of a measuring point,

Repeat the above operation will get the rebound value of measured points which needed.

Inspecting methods

Using Test Hammer inspect the compressive strength for structure or component of concrete which is base on measur-

ing area as basic unit to carry out. This is that the structure or components divided into several measuring area, each

test area distribution of 16 measuring points, one measured area nished then test another, in the structure or structures

to orderly rebound inspect. Specic test method, see the appendix to this manual the industry standard “JGJ/T23-2001

<Technical Specication for Inspecting concrete compressive strength by Rebound Method> The new revision standard

of rebound method has a greater change, Wish our customers seriously and carefully read the standard, it is a guide to

the work of non-destructive testing.

The new revision standard of rebound method,changes are as belows:

1. Measurement strength curve range iiJ£-60MPa?)

2. Increased the calculation method for intensity conversion value of pumping concrete.