REBOUND HAMMER
Rebound hammer test is done to find out the compressive strength of concrete by using rebound hammer as per IS: 13311 (Part 2) – 1992. The underlying principle of the rebound hammer test is
The rebound of an elastic mass depends on the hardness of the surface against which its mass strikes. When the plunger of the rebound hammer is pressed against the surface of the concrete, the pring-controlled mass rebounds and the extent of such a rebound depends upon the surface hardness of the concrete. The surface hardness and therefore the rebound is taken to be related to the compressive strength of the concrete. The rebound value is read from a graduated scale and is designated as the rebound number or rebound index. The compressive strength can be read directly from the graph provided on the body of the hammer.
Procedure to determine strength of hardened concrete by rebound hammer.
i) Before commencement of a test, the rebound hammer should be tested against the test anvil, to get reliable results, for which the manufacturer of the rebound hammer indicates the range of readings on the anvil suitable for different types of rebound hammer.
ii) Apply light pressure on the plunger – it will release it from the locked position and allow it to extend to the ready position for the test.
iii) Press the plunger against the surface of the concrete, keeping the instrument perpendicular to the test surface. Apply a gradual increase in pressure until the hammer impacts. (Do not touch the button while depressing the plunger. Press the button after impact, in case it is not convenient to note the rebound reading in that position.)
iv) Take the average of about 15 readings.
Interpretation of Results
The rebound reading on the indicator scale has been calibrated by the manufacturer of the rebound hammer for horizontal impact, that is, on a vertical surface, to indicate the compressive strength. When used in any other position, appropriate correction as given by the manufacturer is to be taken into account.
You can have the complete details of Non destructive Test by rebound hammer test here
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thank you very much for this info.
how accurate is the rebound hammer test on columns and beams.
Can you let me know that what kind of surface is ready to carry out the rebound hammer test, can we do it directly to texturing surface of aircraft parking apron ?
with regards to percentage of error how this will be incorporated
to the result of rebound test to make the result true and correct.
Pl send to me rebound hammer calibration proceder
haw to calibrate it
B/R
Karunaratna
Dear Sir
Can you send me the calculation of compressive strength from rebound index number in rebound hammer and
Dear Sir
Can you send me the calculation of compressive strength from rebound index number in rebound hammer
DEAR SIR,
THANK U SO MUCH FOR YOUR USEFULL INFORMATION FOR MY EXAM.
Very Good Information, but u can improve that the procedure of calibration for rebound hammer with concrete shoul be read & implements in lab./R&D.
Rebound hammer test is applicable upto which grade of concrete?
Good day, I am in dire needs of the porcedure of rebound test of concrete. this is the only way i can acces. please
include all the important steps if possible each steps must be illustrated. also include the computation.
thank you very much and more power. for the information i am here in saudi arabia
i wish to know the procedures of rebound hammer test is according to which standard? BS or ASTM? what is the code?
winsor probe test is also being used widely.
how can I get the rebound hammer test results verified through the calibrated graph.
I want to road construction magasing and
rebound hammer calibration methord
how $ from where to purchase the rebound hammer& price ?
let me know tha acuracy of rebound result
can i know the material used to make the rebound hammer??? Is it stainless steel, duralumin or some sort of new alloy?? Is the material used to make plunger is same with the material used to make spring and rebound hammer housing??
thank u………………..
sir i want details about rebound hammer test. where the test are carried out?