The Tower of Voices National Memorial
PennStress used NMB Slice Sleeves on the Tower of Voices - Flight 93 Memorial. The columns for were 90ft tall, which is too tall to cast as one piece, so they were broken up into two separate columns, an upper and a lower piece, at approx. 45ft long. Five splice sleeves were used at the base of the lower column in combination with anchor bolts where they connect into the foundation. Nine Splice Sleeves were used at the joint between the upper and lower pieces of the column. Nine additional splice sleeves were used at the top of the upper column where a cap connected to the column. The cap at the top connected into (4) of the upper columns. In total there were (8) 90ft columns, each with an upper and lower piece so there was a total of (16) column pieces. Other than the foundation, the splice sleeves were in the lower portion of the connection, so the open end of the splice sleeve was facing up and filled with grout during the erection vs. pumping the grout in to the connection after the pieces are set.