&gt; A booby trap may be defined as any concealed or camouflaged device designed to cause bodily injury when triggered by any action of a person making contact with the device. This term includes guns, ammunition, or explosive devices attached to trip wires or other triggering mechanisms, sharpened stakes, nails, spikes, electrical devices, lines or wires with hooks attached, and devices for the production of toxic fumes or gases.

Cement doesn't fall under the legal definition.