Pouring the First Pile Caps

< Pile Vacuuming Job | Building the New Bridge | Pouring Pile Caps 2, 3, and 4 >

On Thursday, December 22nd, the bridge was scheduled to be shut down from 8:30 am to approximately 1:00 pm to pour the concrete caps for Piers 5, 6, and 7. This was the first of 5 scheduled pours.

An independent testing firm, Mayes Testing, has been hired by TICC to test the concrete in the trucks for the correct design mix and strength (4000 psi). Samples were taken from each truck before they backed up to the concrete pump truck, which was located on the bridge. According to the Exeltech Engineer and Mayes Testing, the samples taken meet the design criteria.

The load limits on our existing bridge still apply, so the concrete trucks were limited to 3 yards per truck. As one concrete truck left, another was staged and ready to offload. Each empty truck left the bridge and made a stop at a large collector ecology pan to clean their chute and truck of excess concrete. Another smaller pan was placed behind the pumper truck which collected any concrete that might have spilled during the transfer from the concrete truck to the pumper truck. A total of 23 concrete truck loads were used for this pour.

New Pier 5 was the first pile cap to be poured. Each of the 3 steel piles was filled with concrete first and then the pile cap. The hose containing the concrete extends to the bottom of the pile and is lifted as the concrete fills the inside of the steel pile and the pile cap wooden form.

A long concrete vibrator was used to make sure the concrete flowed properly and filled all the areas so no voids or air pockets would be present in the concrete and assures the concrete properly encases the reinforcing steel.

Once the pile cap was poured, some of the supports were removed and the top of the pile cap was troweled to a smoothed finish.

After troweling, a curing agent was sprayed on the wet concrete. Sheets of black plastic were then placed on top of the wet concrete and another sheet was draped over the entire pile cap and nailed in place. This was done to provide protection from the rain and low temperature. The pile cap was now left to cure.

This same process was used for the next two pile caps. The pour was delayed when the concrete supplier diverted some of their trucks to another job without notifying American. This resulted in an extended bridge closure which had not been anticipated. The supplier has promised that this will not happen again.

The last concrete truck drove off the bridge at 3:00 pm. The pumper truck backed off the bridge at 3:20 pm. The bridge was cleared of all the equipment and was opened back up to traffic at 3:45 pm. The day still wasn't over for the American Construction crew. They still had to finish covering the last pile cap and move the barge back to its nightly mooring spot.

Three pile caps complete and 12 more to go. Of course, this doesn't include Pier 1 and Pier 17, which are the concrete abutments.