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Rebound Hammer Test

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.

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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.

rebound-hammer-non-destructive-concrete-test

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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Kanwarjot Singh

Kanwarjot Singh is the founder of Civil Engineering Portal, a leading civil engineering website which has been awarded as the best online publication by CIDC. He did his BE civil from Thapar University, Patiala and has been working on this website with his team of Civil Engineers.

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85 comments on "Rebound Hammer Test"

spike says:

Dear Sir,
Please send the procedure on how to calculate the rebound hammer result obtained at site to get the concrete strength result, calculation procedures with example, and BS specifications on various concrete strength.
Thanks for your help.

jena says:

Dear Sir,
Please send the procedure on how to calculate the rebound hammer result obtained at site to get the concrete strength result, calculation procedures with example, and BS specifications on various concrete strength.
Thanks for your help

arif says:

Dear Sir,
i want to ask,
is the result with hammer test is ‘same’ with the result with crushing machine(Universal testing machine)?

i have done my research with hammer test but the result is less 10-15% than crushing machine.

my test using cube 15 x 15 x 15 cm, and 144 cube ive been compare with utm (crushing machine).

thanks a lot b4
regards
arif

Gilbert D. Abarra says:

Rebound Hammer Readings and indicated concrete compressive strength derived there from are not accurate and should not be used for determination of concrete strength except in relative qualitative basis only

Wubete says:

Dear sir/madam,
Please send the procedure on how to calculate the rebound hammer result obtained at site to get the 28 days concrete Compressive strength result, calculation procedures with example, and BS specifications on various concrete strength.
Thanks for your help

Dumindu Warapitiya, B.Sc.Eng.(Hons), AMIE(SL) says:

Dear Sir/Madam,

Pls. let me know the possible tolerrance of a particular reading, obtained using Rebound Hammer. (for eg. if the strength of a concrete is read as 38 N/mm2, using the rebound hammer, what will be the range it might vary, when a core sample of same concrete, is crushed in a Compressive Strength testing machine ? )

Yogesh Rajpal says:

Please send the procedure on how to calculate the rebound hammer result obtained at site to get the concrete strength result

Varghese Tharakan says:

Dear Sir,

Please send us the Test Procedure for Concrete Hammer Test, We, Hyundai Engineering and Construction Co. Ltd., are the one of Civil and Electrical Contractor in Libya and we want to test some concrete pile tower foundations through this test hammer.

Thanks and Regards
Varghese Tharakan

hanish m says:

pleas send detaild procedure on rebound hammer test

nandini says:

sir, pl tell the cost of rebound hammer testing machine and where it is available in chennai, Tamil nadu .

H.C.SHUKLA says:

kindly tell me that compressive sterenth of concrete which is tested by cube testing machine is 100% equal to rebound hammer tast means results shall be same ?

pardeep says:

Dear Sir,
Please send the procedure on how to calculate the rebound hammer result obtained at site to get the concrete strength result, calculation procedures with example, and BS specifications on various concrete strength.
Thanks for your help.

Neil says:

Please could you explain to me how the rebound hammer test calculates the compressive strength of concrete?

Is this the most accurate non destructive test for measuring the compressive strength of concrete?

Thanks

SAMEER, Pune says:

Please send the procedure on how to calculate the rebound hammer result obtained at site to get the concrete strength result, calculation procedures with example, and BS specifications on various concrete strength.
Thanks for your help.

Reply

NANCY says:

pls send the procedure of using the rebound hammer test. thank you.

subra says:

Sir,pls send the procedure of using the rebound hammer test results obtained atsite to get the concrete strength

Er.suresh Prasad Yadav says:

Sir,
pls send the procedure of using the rebound hammer test results obtained atsite to get the concrete strength.

farish says:

Dear Sir,
Please send the procedure on how to calculate the rebound hammer result obtained at site to get the concrete strength result.

shantaram sitaram kurhade says:

Dear Sir,
Pl. send the procedure of how to calculate the rebound hammer result at site to get concrete strength result.

miss syira says:

Please send the procedure on how to calculate the rebound hammer result obtained at site to get the concrete strength result.

Haamid says:

Dear Sir,
Pl. send the procedure of how to calculate the rebound hammer result at site to get concrete strength result.

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