Lincoln Memorial Reflecting Pool

The old reflecting pool, completed in 1924 and demolished in 2009, held 6.75 million gallons of water, much of which evaporated or continually leaked from the pool. The old reflecting pool was built with an asphalt and tile bottom on poorly supported soil consisting primarily of marshes. The unstable subgrade had deflected twelve inches over the past 90 years under the pressure exerted by the reflecting pool. In 1980, a new concrete slab was poured over the existing slab, but the added weight simply worsened the soil settlement and subsequent structure leakage. The old reflecting pool could not circulate its often stagnant water and was drawing more than 30 million gallons of city potable water per year.

Stabilize the subgrade to minimize the settlement potential and subsequent damage to the new reflecting pool structure.

• Provide a concrete mix design that met the project specifications for durability, shrinkage, and watertightness.
• Provide a cost effective and efficient joint sealing product
• Ensure watertightness of the entire system at numerous construction joints.

The new reflecting pool is founded on 2,133 timber piles driven into the bedrock to providing more stable support. Corman Construction Inc., decided to utilize a watertight concrete system provided by Sika Corporation in order to meet the project specifications. 

In conjunction with Sika concrete admixtures, Sika Greenstreak hydrophilic joint sealing strip Hydrotite was used at all construction joints to provide a whole system solution. This system approach to watertight construction is referred to as Sika’s “Whitebox”. During the rehabilitation, Sika was a single source provider of concrete construction products needed to build watertight structures as evidenced by the successful implementation of the “Whitebox” system.

Besides the pool renovation itself, the additional water management improvements included new water re-circulating machinery, a new pump building, which houses a second set of re-circulating pumps, a filtration system and ozone disinfection. 58 outlets are now used to fill the structure, flooding the pool with approximately 800 gallons of water per minute taking approximately 5 days to fill the entire structure.