A lost hiker wearing only shorts was rescued after spending the night off trail in a concrete tube, Arizona deputies say. A pair of friends went for a hike on Black Canyon Trail in Black Canyon City ...
Or the tube can be placed on the outside so once the concrete filling has hardened, the pieces can be removed – and reused." ...
The core is a large robust two-foot thick structural concrete tube housing the elevators, emergency stairs, and utilities. It provides safe access for occupants and provides primary strength for ...