Rebound Hammer Test on Concrete
Rebound Hammer:
Solid Test Hammer Specification :
It is like the above yet is utilized for testing concrete with oversize totals (for which test, solid shapes guarantee no dependable outcomes) and for testing concrete roads. Its plunger is more extensive thusly, the measure of cement came to by the effect is considerably more noteworthy. With this model additionally, the outcomes got are inside 20% of the genuine compressive quality. The instrument is provided with two handles which can be connected to the body of the solid test pound for doing the test effectively. Finish with granulating stones.
Methodology FOR REBOUND HAMMER TEST ON CONCRETE:
Methodology for bounce back sled test on solid structure begins with adjustment of the bounce back mallet. For this, the bounce back mallet is tried against the test iron block made of steel having Brinell hardness number of around 5000 N/mm2.
After the bounce back sled is tried for precision on the test iron block, the bounce back mallet is held at right edges to the surface of the solid structure for taking the readings. The test in this way can be led on a level plane on a vertical surface and vertically upwards or downwards on flat surfaces as appeared in figure beneath:
On the off chance that the bounce back mallet is held in the middle of the road edge, the bounce back number will be diverse for a similar cement.
The accompanying focuses ought to be seen amid testing.
(a) The solid surface ought to be smooth, perfect and dry.
(b) Ant free particles ought to be rubbed off from the solid surface with a granulating wheel or stone, before pound testing.
(c) The purpose of effect of bounce back sleds on solid surface ought to be no less than 20mm far from edge or shape intermittence.
Six readings of bounce back number are taken for each purpose of testing and a normal of estimation of the readings is taken as bouncing backfile for the comparing purpose of perception on a solid surface.
How the connection between's compressive quality of cement and bounce back number is acquired:
The most reasonable technique for acquiring the connection between's compressive quality of cement and bounce back number is to test the solid 3D shapes utilizing pressure testing machine and in addition utilizing bounce back mallet all the while. In the first place, the bounce back number of the solid 3D square is taken and afterward the compressive quality is tried on pressure testing machine. The settled load required is of the request of 7 N/mm2 when the effect vitality of the sled is around 2.2 Nm. The heap ought to be expanded for aligning bounce back sleds of more prominent effect vitality and diminished for adjusting bounce back mallets of lesser effect vitality. The test examples ought to be as expansive a mass as conceivable keeping in mind the end goal to limit the size impact on the test consequence of a full-scale structure. 150mm solid shape examples are favored for adjusting bounce back sleds of lower affect vitality (2.2Nm), while for bounce back mallets of higher effect vitality, for instance, 30 Nm, the test 3D squares ought not to be littler than 300mm.
The solid shape examples ought to be kept at room temperature for around 24 hours subsequent to taking it out from the curing lake, before testing it with the bounce back sled. To get a connection between's bounce-back numbers and quality of wet cured and wet tried solid shapes, it is important to build up a relationship between's the quality of wet tried 3D squares and the quality of dry tried 3D shapes on which bounce back readings are taken. An immediate connection between's bounce-back numbers on wet blocks and the quality of wet 3D shapes isn't suggested. Just the vertical countenances of the shapes as cast ought to be tried. No less than nine readings ought to be gone up against every one of the two vertical countenances available in the pressure testing machine when utilizing the bounce back sleds. The purposes of effect on the example must not be closer an edge than 20mm and ought to be at the very least 20mm from each other. Similar focuses must not be affected more than once.
Understanding of Rebound Hammer Test Results:
Subsequent to acquiring the connection between's compressive quality and bounce back number, the quality of structure can be evaluated. When all is said in done, the bounce back number increments as the quality increments and is additionally influenced by various parameters i.e. sort of bond, kind of total, surface condition and dampness substance of the solid, curing and period of solid, carbonation of solid surface and so forth. In addition, the bounce backfile is characteristic of the compressive quality of cement up to a restricted profundity from the surface. The inward splits, blemishes and so forth or heterogeneity over the cross segment won't be shown by bounce-back numbers.
Thusly the estimation of the quality of cement by a bounce back sled strategy can't be held to be exceptionally exact and likely precision of forecast of solid quality in a structure is ± 25 percent. On the off chance that the connection between bounce back record and compressive quality can be found by tests on center examples acquired from the structure or standard examples made with a similar solid materials and blend extent, at that point the exactness of results and certainty subsequently gets significantly expanded.
Solid Test Hammer Specification :
It is like the above yet is utilized for testing concrete with oversize totals (for which test, solid shapes guarantee no dependable outcomes) and for testing concrete roads. Its plunger is more extensive thusly, the measure of cement came to by the effect is considerably more noteworthy. With this model additionally, the outcomes got are inside 20% of the genuine compressive quality. The instrument is provided with two handles which can be connected to the body of the solid test pound for doing the test effectively. Finish with granulating stones.
Methodology FOR REBOUND HAMMER TEST ON CONCRETE:
Methodology for bounce back sled test on solid structure begins with adjustment of the bounce back mallet. For this, the bounce back mallet is tried against the test iron block made of steel having Brinell hardness number of around 5000 N/mm2.
After the bounce back sled is tried for precision on the test iron block, the bounce back mallet is held at right edges to the surface of the solid structure for taking the readings. The test in this way can be led on a level plane on a vertical surface and vertically upwards or downwards on flat surfaces as appeared in figure beneath:
On the off chance that the bounce back mallet is held in the middle of the road edge, the bounce back number will be diverse for a similar cement.
The accompanying focuses ought to be seen amid testing.
(a) The solid surface ought to be smooth, perfect and dry.
(b) Ant free particles ought to be rubbed off from the solid surface with a granulating wheel or stone, before pound testing.
(c) The purpose of effect of bounce back sleds on solid surface ought to be no less than 20mm far from edge or shape intermittence.
Six readings of bounce back number are taken for each purpose of testing and a normal of estimation of the readings is taken as bouncing backfile for the comparing purpose of perception on a solid surface.
How the connection between's compressive quality of cement and bounce back number is acquired:
The most reasonable technique for acquiring the connection between's compressive quality of cement and bounce back number is to test the solid 3D shapes utilizing pressure testing machine and in addition utilizing bounce back mallet all the while. In the first place, the bounce back number of the solid 3D square is taken and afterward the compressive quality is tried on pressure testing machine. The settled load required is of the request of 7 N/mm2 when the effect vitality of the sled is around 2.2 Nm. The heap ought to be expanded for aligning bounce back sleds of more prominent effect vitality and diminished for adjusting bounce back mallets of lesser effect vitality. The test examples ought to be as expansive a mass as conceivable keeping in mind the end goal to limit the size impact on the test consequence of a full-scale structure. 150mm solid shape examples are favored for adjusting bounce back sleds of lower affect vitality (2.2Nm), while for bounce back mallets of higher effect vitality, for instance, 30 Nm, the test 3D squares ought not to be littler than 300mm.
The solid shape examples ought to be kept at room temperature for around 24 hours subsequent to taking it out from the curing lake, before testing it with the bounce back sled. To get a connection between's bounce-back numbers and quality of wet cured and wet tried solid shapes, it is important to build up a relationship between's the quality of wet tried 3D squares and the quality of dry tried 3D shapes on which bounce back readings are taken. An immediate connection between's bounce-back numbers on wet blocks and the quality of wet 3D shapes isn't suggested. Just the vertical countenances of the shapes as cast ought to be tried. No less than nine readings ought to be gone up against every one of the two vertical countenances available in the pressure testing machine when utilizing the bounce back sleds. The purposes of effect on the example must not be closer an edge than 20mm and ought to be at the very least 20mm from each other. Similar focuses must not be affected more than once.
Understanding of Rebound Hammer Test Results:
Subsequent to acquiring the connection between's compressive quality and bounce back number, the quality of structure can be evaluated. When all is said in done, the bounce back number increments as the quality increments and is additionally influenced by various parameters i.e. sort of bond, kind of total, surface condition and dampness substance of the solid, curing and period of solid, carbonation of solid surface and so forth. In addition, the bounce backfile is characteristic of the compressive quality of cement up to a restricted profundity from the surface. The inward splits, blemishes and so forth or heterogeneity over the cross segment won't be shown by bounce-back numbers.
Thusly the estimation of the quality of cement by a bounce back sled strategy can't be held to be exceptionally exact and likely precision of forecast of solid quality in a structure is ± 25 percent. On the off chance that the connection between bounce back record and compressive quality can be found by tests on center examples acquired from the structure or standard examples made with a similar solid materials and blend extent, at that point the exactness of results and certainty subsequently gets significantly expanded.
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