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A typical Earth Covered Magazine bunker. Photo Credit: US Army Corps of Engineers
A typical Earth Covered Magazine bunker. Photo Credit: US Army Corps of Engineers

Earth Covered Magazine (ECM) structures are built to safely store ammunition and explosives, and are frequently used by the Department of Defense and the US military. While they are not designed to resist the damaging effects from an accidental explosion, a structurally sound ECM can effectively limit these effects in an explosion caused by small amounts of ammunition and explosives. In this case, cracks initiated in the floor of an earth covered magazine bunker as a result of foundation movement and poor sub-grade conditions. Over time, the cracks spread to the bunker’s walls and ceiling, which led to leaks and concrete spalling. The bunker had lost its structural integrity, and considering the highly explosive contents within, required immediate strengthening.

The bunker's extensive cracking threatened its structural integrity.
The bunker’s extensive cracking threatened its structural integrity.

HJ3’s CarbonSeal™ carbon fiber was chosen as the strengthening system of choice for the magazine bunker repair. Prior to installing the carbon fiber, perpendicular saw cuts were made across all cracks in the floor and walls. HJ3’s patented carbon laminate strips were inserted into each saw cut, and the cracks were injected with epoxy to set the laminate in place. The rest of the bunker’s interior was cleaned with an abrasive blast to remove all delaminated concrete and dust. A cementitious grout helped to restore the bunker’s uniform surface, and finally, the CarbonSeal™ carbon fiber was saturated and installed along the cracked walls and ceiling.

The CarbonSeal carbon fiber is applied to the prepared walls.
The CarbonSeal carbon fiber is applied to the prepared walls.

The magazine bunker repair was successfully completed in just one day. By repairing the cracked bunker instead of replacing it and building a new one, the client saved a significant amount of money while simultaneously preventing the waste of several valuable resources by avoiding the manufacture of replacement concrete and steel. The repair prevented more than 4 tons of steel and concrete from potentially going to landfills, almost 250,000 gallons of water and 33,000 kWh of energy from being wasted, and more than 8 tons of carbon dioxide emissions from polluting the atmosphere.

If you’re interested in HJ3’s CarbonSeal system for your own earth covered magazine bunker, or another corroded concrete structure, write us today at info@hj3.com.