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Stabilize Historical Boundary Fence Markers
Chamizal National Memorial » Stabilize Historical Boundary Fence Markers » Document List
Chamizal National Memorial proposes to preserve an important part of El Paso's history, the 27 historic boundary fence posts that run along the north side of the park along Paisano Drive. These historic remnants of what was once a part of Cordova Island are actively cracking, corroding, and spalling (chipping into smaller pieces). Constructed in 1939, these 27 posts are the only remaining visible historic resources marking a historic boundary between Mexico and the United States. The land on which Chamizal National Memorial sits, as defined by the posts, was Mexican territory until 1963 and the signing of the Chamizal Convention.
The proposed preservation and rehabilitation process will involve the following: low presser water washing the posts with a non-ionic detergent; reattaching sections that have detached using threaded rod and epoxy; filling internal voids with grout injections, and compensating for surface loss with concrete that includes aggregate and coloring similar to the original.
An important part of the preservation process includes reversing the corrosion process of the reinforcing steel rods inside the cement post structures. As the steel rods corrode, they expand and force the cement apart. If this process is not inhibited, the posts will continue to deteriorate.
To correct this condition and prevent further deterioration, the park proposes to use an Impressed Current Cathodic Protection (ICCP) system. The ICCP system the park proposes to use is the ELGARD anode ribbon mesh system. Used world-wide to protect reinforced concrete, the ELGARD anodes have a life expectancy of 75 years. The system consists of two runs of ribbon mesh, one on the east face and one on the west face, that are installed within the concrete post. Where the reinforced steel is exposed during the repairs, the anode ribbon would be attached to the bars with a non-metallic clip. Where the concrete is sound, the ribbon would run in a small saw cut slot that is backfilled with grout. The ribbons would start at the top of the posts and run to 6" below ground. The ribbons would then be spliced to an underground header cable that connects each of the posts to a main low voltage line buried in a deeper trench.
The ICCP form of reinforced concrete protection ia a well-established method that, simply stated, involves creating an environment in which the electrical charges essential for corrosion activity are reversed. As a result, the corrosion occurs in an external anode supplied to the system and not in the fence post.
The proposed preservation and rehabilitation process will involve the following: low presser water washing the posts with a non-ionic detergent; reattaching sections that have detached using threaded rod and epoxy; filling internal voids with grout injections, and compensating for surface loss with concrete that includes aggregate and coloring similar to the original.
An important part of the preservation process includes reversing the corrosion process of the reinforcing steel rods inside the cement post structures. As the steel rods corrode, they expand and force the cement apart. If this process is not inhibited, the posts will continue to deteriorate.
To correct this condition and prevent further deterioration, the park proposes to use an Impressed Current Cathodic Protection (ICCP) system. The ICCP system the park proposes to use is the ELGARD anode ribbon mesh system. Used world-wide to protect reinforced concrete, the ELGARD anodes have a life expectancy of 75 years. The system consists of two runs of ribbon mesh, one on the east face and one on the west face, that are installed within the concrete post. Where the reinforced steel is exposed during the repairs, the anode ribbon would be attached to the bars with a non-metallic clip. Where the concrete is sound, the ribbon would run in a small saw cut slot that is backfilled with grout. The ribbons would start at the top of the posts and run to 6" below ground. The ribbons would then be spliced to an underground header cable that connects each of the posts to a main low voltage line buried in a deeper trench.
The ICCP form of reinforced concrete protection ia a well-established method that, simply stated, involves creating an environment in which the electrical charges essential for corrosion activity are reversed. As a result, the corrosion occurs in an external anode supplied to the system and not in the fence post.