johnnyClaims
New Member
- Joined
- Nov 15, 2019
- Messages
- 1
Hi,
I am researching how to bury valuables underground in a way that makes it very difficult or impossible to use metal detection or ground-penetrating radar to discover the burial locations.
Suppose I am building a structure on a concrete slab of perhaps 100ft x 50feet in size, with a slab thickness of 6". At one or more locations beneath the slab I'd like to bury, for instance, a 2" diameter x 6" long PVC pipe containing silver coins, say, 30" below grade. (So, 8" of concrete, then 22" of soil cover.)
6" of concrete with 1/2" rebar on a 12" x 12" grid itself might present some challenges for some kinds of detectors, but I want to substantially "upgrade" the concrete's resistance to metal detectors if possible.
Aside from normal rebar, could I add say, 2-4% by weight of a finely-ground conductive metal powder like iron or aluminum to the concrete mix? (Assume for sake of discussion that this would not adversely affect the pouring or strength / durability characteristics of the concrete -- I would research those impacts elsewhere.) Would that be enough metal content to confuse metal detectors?
Maybe 2-4% metal content in the mix isn't anywhere near enough. What about dumping say 1/2" thick layer of solid aluminum shot on the ground before the concrete is poured? (Say 5-7mm diameter shot size --effectively making highly-conductive but rough-surfaced metallic mat beneath the concrete.) (Again, ignore any issues around aluminum-concrete chemical or mechanical incompatibility, I will research those elsewhere.)
Please also suggest if there are other methods that might be cost-effective and not too hard to implement.
I am researching how to bury valuables underground in a way that makes it very difficult or impossible to use metal detection or ground-penetrating radar to discover the burial locations.
Suppose I am building a structure on a concrete slab of perhaps 100ft x 50feet in size, with a slab thickness of 6". At one or more locations beneath the slab I'd like to bury, for instance, a 2" diameter x 6" long PVC pipe containing silver coins, say, 30" below grade. (So, 8" of concrete, then 22" of soil cover.)
6" of concrete with 1/2" rebar on a 12" x 12" grid itself might present some challenges for some kinds of detectors, but I want to substantially "upgrade" the concrete's resistance to metal detectors if possible.
Aside from normal rebar, could I add say, 2-4% by weight of a finely-ground conductive metal powder like iron or aluminum to the concrete mix? (Assume for sake of discussion that this would not adversely affect the pouring or strength / durability characteristics of the concrete -- I would research those impacts elsewhere.) Would that be enough metal content to confuse metal detectors?
Maybe 2-4% metal content in the mix isn't anywhere near enough. What about dumping say 1/2" thick layer of solid aluminum shot on the ground before the concrete is poured? (Say 5-7mm diameter shot size --effectively making highly-conductive but rough-surfaced metallic mat beneath the concrete.) (Again, ignore any issues around aluminum-concrete chemical or mechanical incompatibility, I will research those elsewhere.)
Please also suggest if there are other methods that might be cost-effective and not too hard to implement.