Table of Contents
How does rebound hammer test work?
The rebound hammer is a nondestructive testing apparatus, whereby the rebound of the spring driven mass is measured after its impact with concrete surface. The output of the rebound hammer is referred to as rebound number and are correlated with surface hardness of concrete.
How accurate is a rebound hammer?
The results show that the compressive strength prediction using rebound hammer was accurate in the range of 48 to 58 MPa with an error of 15.32%, but underestimates the actual strength of the samples in the upper and lower regions.
What does rebound hammer measure?
The rebound hammer (often a “Schmidt” hammer) measures the rebound of a weight from the back of an “anvil” pushed against the concrete surface. The method may be compared to dropping a large ball-bearing onto a concrete surface.
How do you find the compressive strength of a rebound hammer?
Compressive strength (N/mm2) = Maximum crushing load / Cross – sectional area of specimen. Schmidt Rebound Hammer test is a non- destructive test.
How do you test compressive strength?
compressive strength test, mechanical test measuring the maximum amount of compressive load a material can bear before fracturing. The test piece, usually in the form of a cube, prism, or cylinder, is compressed between the platens of a compression-testing machine by a gradually applied load.
Which quality of concrete is tested by rebound hammer test?
compressive strength
Rebound hammer test is done to find out the compressive strength of concrete by using rebound hammer as per IS: 13311 (Part 2) – 1992….Procedure To Determine Strength Of Hardened Concrete By Rebound Hammer.
| Average Rebound Number | Quality of Concrete |
|---|---|
| 30 to 40 | Good layer |
| 20 to 30 | Fair |
| < 20 | Poor concrete |
| 0 | Delaminated |
Is code used in rebound hammer test?
Objective of Rebound Hammer Test As per the Indian code IS: 13311(2)-1992, the rebound hammer test have the following objectives: To determine the compressive strength of the concrete by relating the rebound index and the compressive strength. To assess the uniformity of the concrete.
How do you test concrete strength?
One of the most common new methods is what is called Rebound Hammer Test. This method required a tool that uses a spring release to drive a plunger-tipped hammer down into the concrete that is being tested. The distance the hammer is rebounded is measured and assigned a score between 10 and 100.
What is compressive strength test of concrete?
The Compressive strength of a material is determined by the ability of the material to resist failure in the form cracks and fissure. In this test, the push force applied on the both faces of concrete specimen and the maximum compression that concrete bears without failure is noted.
What is compressive strength of concrete?
Concrete compressive strength requirements can vary from 2500 psi (17 MPa) for residential concrete to 4000 psi (28 MPa) and higher in commercial structures. Higher strengths up to and exceeding 10,000 psi (70 MPa) are specified for certain applications.
What is fineness test of cement?
Fineness of Cement is measured by sieving cement on standard sieve. The proportion of cement of which the cement particle sizes are greater than the 90 micron is determined.