Hammer sounding or sounding hammer
Hammer sounding or sounding hammer
(OP)
I am going to be on site with some other folks next week to take a look at some concrete cracking. I am curious about hammer sounding, I have never done it. From what I have read a common hammer can be used to strike concrete and the sound generated is indicative of concrete quality. For those who have experience doing this, is the hammer a special type of any common hammer will do? Also, how hard are you supposed to hit the hammer?
I won't be doing the hammer sounding but I want to know at least the basics of it.
I won't be doing the hammer sounding but I want to know at least the basics of it.






RE: Hammer sounding or sounding hammer
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Hammer sounding or sounding hammer
BA
RE: Hammer sounding or sounding hammer
As for striking the CMU with the hammer, we "first do ho harm" to either the CMU or the framing hammer. Those things are expensive!
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Hammer sounding or sounding hammer
Cracks in concrete often have little or nothing to do with the integrity of the concrete. In fact, higher strength concrete will often have more significant cracks because most cracks are caused by shrinkage, particularly with slabs on grade.
You can check for voids under the slab using a wooden dowel, end down, dropped straight through your hand and caught on the rebound. You will only need to drop the dowel 6 to 8 inches. When you have voids in or under the slab, you will typically hear a dull thud rather than a resounding "ring". The dowel I use for this is about 1" in diameter and 5 feet long. Sound on both sides of cracks and joints to check for curling.
RE: Hammer sounding or sounding hammer
1. are the cracks in concrete walls? Is there any particular pattern to the cracking?
2. are the cracks on floor slabs?
RE: Hammer sounding or sounding hammer
I use hammer tapping to detect delaminations in reinforced concrete slabs/beams/walls/columns. The delams are primarily due to corrosion of the reinforcement and can result in cracks showing on the surface. The hollow sound you get when hammer tapping delaminated concrete is very very different from that of solid concrete. You don't have to hit very hard. If the concrete is cracked due to reasons other than delaminations, the hammer tapping will likely not provide any useful information.
RE: Hammer sounding or sounding hammer
Like the others want to know- what is the structure?
RE: Hammer sounding or sounding hammer
RE: Hammer sounding or sounding hammer
RE: Hammer sounding or sounding hammer
RE: Hammer sounding or sounding hammer
A regular hammer works just fine. Chains dragged or flipped work well, too, as does a golf ball bounce. Well, these work great for finding large-ish areas of delaminations, not so great for small areas or cracks. No need to hit hard - you just listen for a difference in sound.
What exactly are you going to be doing? Type of material? Structure use/age/location? Wall or slab?
RE: Hammer sounding or sounding hammer
There are days when I wake up feeling like the dumbest man on the planet, then there are days when I confirm it.