Rebound Hammer Test
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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.
December 15th, 2008 at 1:48 pm
thank you very much for this info.
December 20th, 2008 at 6:26 am
how accurate is the rebound hammer test on columns and beams.
December 28th, 2008 at 12:11 pm
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 ?
January 7th, 2009 at 9:19 am
with regards to percentage of error how this will be incorporated
to the result of rebound test to make the result true and correct.
March 29th, 2009 at 8:33 am
Pl send to me rebound hammer calibration proceder
haw to calibrate it
B/R
Karunaratna
April 1st, 2009 at 2:16 pm
Dear Sir
Can you send me the calculation of compressive strength from rebound index number in rebound hammer and
April 19th, 2009 at 9:14 pm
Dear Sir
Can you send me the calculation of compressive strength from rebound index number in rebound hammer
April 23rd, 2009 at 5:49 am
DEAR SIR,
THANK U SO MUCH FOR YOUR USEFULL INFORMATION FOR MY EXAM.
June 13th, 2009 at 6:42 am
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.
June 16th, 2009 at 8:53 am
Rebound hammer test is applicable upto which grade of concrete?
July 7th, 2009 at 1:38 pm
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
July 22nd, 2009 at 7:07 am
i wish to know the procedures of rebound hammer test is according to which standard? BS or ASTM? what is the code?
August 13th, 2009 at 6:43 am
winsor probe test is also being used widely.
August 21st, 2009 at 8:12 am
how can I get the rebound hammer test results verified through the calibrated graph.
September 16th, 2009 at 4:52 am
I want to road construction magasing and
rebound hammer calibration methord
September 20th, 2009 at 1:57 am
how $ from where to purchase the rebound hammer& price ?
October 17th, 2009 at 5:31 am
let me know tha acuracy of rebound result
October 19th, 2009 at 11:15 pm
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??
October 20th, 2009 at 12:52 pm
thank u………………..
October 29th, 2009 at 8:32 am
sir i want details about rebound hammer test. where the test are carried out?
November 4th, 2009 at 9:58 pm
dear sir
is it enough if we just do the rebound hammer test on the slab?
why my client still want to do the coring test on the slab?
the problem on the slab is just the surface cracks.
can u please provide the facts that doing the rebound hammer test is just enough than doing the coring test.
November 13th, 2009 at 2:36 am
dear sir kindly send me the details regarding the values that indicates hard structure which are obtained from rebonnd hammer
and also a clear picture of rebound hammer showing all the readings on it
December 2nd, 2009 at 2:02 am
Please tell me what’s the importance in feilds in this experiment and disadvantage & advantages.
December 14th, 2009 at 12:12 am
hi pease sir let me know about correct
ion factor of rebound hammer test how many factors apply against angle
what is frictional error% please send me information about factors
against angles and also zero angle
January 4th, 2010 at 8:10 pm
I really want to know, is it accepted if the concrete strength is to be 29.5 kN/mm2?
January 8th, 2010 at 9:33 pm
how can I get the rebound hammer test results verified through the calibrated graph?i don’t know how to use the calibrated graph..can u explain it to me…thanxx..
February 16th, 2010 at 2:52 am
Please give the detailed information about Rebound Hammer test..Please also explain its graph deeply..I will be very oblige to u.
February 24th, 2010 at 1:08 am
Average Rebound Number is 22 for concrete. What will be the equivalent compressive strength of concrete in N/mm2 and Kg/cm2.
February 28th, 2010 at 7:32 am
1.is it recomended to do a rebound hammer test on 10cm thick floor slab which is casted on 25cm thick
hard core?
2.Would you let me know that what kind of surface is ready to carry out the rebound hammer test
and please tell me other procedures
February 28th, 2010 at 7:45 am
Dear sir
what happened if rebound hammer test done on rough surface of concrete?