Smith-Midland completes Design-Build Project for Smithsonian National Zoo in Washington, DC

August 27, 2015 | Associate / Plant News

Smith Midland Smithsonian National Zoo retaing wall

AGC of DC and Washington Building Congress AWARD WINNING precast concrete project –
Smith-Midland Corporation (SMC) has manufactured an 850 foot long x 30 foot high simulated stone retaining wall for the Smithsonian National Zoological Park in Washington, DC. The wall was needed to replace existing structures along an extensive drop off along the entrance road above parking lot C.

General Contractors Hensel Phelps and Athena Construction Group worked with SMC to manufacture the precast concrete panels, and M & J Welding to complete the welding and wall erection. Originally designed to be cast in place, Hensel Phelps rethought the process, proposing a design-build project involving the use of a shotcrete wall, and placement of precast concrete panels as a facing.

The panels were formed and hand-stained to mimic the look and color variations of a natural stone wall, matching the stone wall located on the nearby Rock Creek Parkway. SMC prepared a mock-up of a wall section and delivered it on-site at the National Zoo prior to job initiation to serve as a visual aid for what was to be accomplished. “This wall has all the color variations of a natural wall, and is a permanent penetrating stain that will last indefinitely,” says Smith-Midland’s president, Ashley Smith. “We are proud of this project that exemplifies Smith-Midland’s ability to innovate, improve, and initiate products that are current and pleasing to the eye. We worked out the logistics with multiple contractors on this project, and delivered a quality product for our customer.”

Panels were erected using a crane, and were connected to the shotcrete wall with stainless steel plates and anchors. Seven panels were set per shift, which equaled one panel set per hour. Speed of construction was fast. Within a few weeks, a majority of the 30 foot high wall was completed. Hensel Phelps’ site manager, Kim Slusher, expressed feelings that the benefit of constructing a wall this way, compared to what was originally designed as a cast in place wall was profound, “You have a better looking wall this way. The joints all lined up well and the shoulder joints are set consistently. Speed of construction was good. The owner is pretty happy.”

About Smith-Midland Corporation
Smith-Midland Corporation (DE) is a publically traded company (OTCQB: SMID). Smith-Midland (VA) develops, manufactures and sells a broad array of precast concrete products for use primarily in the construction, transportation and utilities industries. SMC has two manufacturing facilities located in Midland, Virginia and Reidsville, North Carolina. Easi-Set® Worldwide, a wholly-owned subsidiary of Smith-Midland Corporation (DE), licenses the production and sale of SMC developed products around the world. For more information, please call (540) 439-3266 or visit

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