Rebound Hammer Test On Concrete Ppt

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Rebound hammer test on concrete ppt. Around each point of observation six readings of rebound indices are taken and average of these. Testing the strength of concrete without destructing or breaking it after hardening is a complex task. Concrete test hammer ideally suited for on site tests of concrete and is widely used instrument for analyzing the uniformity and compressive strength characteristics of concrete structures and detection of weak spots in the concrete. The suitable methods for checking the calibration of the rebound hammer is to test the concrete cube of size 150mm 150mm 150mm with the help of rebound hammer and then with the compression testing machine ctm.

It is necessary to calibrate the rebound hammer before carrying out the test on hardened concrete. Rebound hammer test is conducted around all the points of observation on all accessible faces of the structural element. As we already discussed the compressive strength of concrete by concrete cube test which is a destructive test worked out in the lab. 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.

13311 part 2 1992. Rebound hammer rebound hammer test is done to find out the compressive strength of concrete by using rebound hammer as per is. Rebound values are read from a scale for subsequent calculation of the mean. Thus many people do not trust the rebound test results.

Rebound hammer test should not be conducted on rough surfaces as a result of incomplete compaction loss of grout spalled or tooled concrete surface. Principles of the rebound hammer ernst schmidt a swiss engineer developed the modern rebound hammer in 1948. Concrete surfaces are thoroughly cleaned before taking any measurement. For taking a measurement the rebound hammer should be held at right angles to them surface of the concrete member.

This article is to discuss the rebound hammer and how to successfully use it to evaluate concrete. Rebound values are read from a scale for subsequent calculation of the mean. The point of impact of rebound hammer on concrete surface should be at least 20mm away from edge or shape discontinuity. The rebound hammer test is one of the non destructive tests used to check the compressive strength of concrete.

An empirical relationship has been determined between the a absorbed by the concrete when given a high impact and its compressive. The test can thus be conducted horizontally on vertical surfaces or vertically upwards or downwards on horizontal surfaces if the situation demands the rebound hammer can be.