Winner: Southwest REgion

The Xcel Energy Line W3444 Island Project in La Crosse involved the construction of a utility transmission line base structure located on an island within the Mississippi River.

The project consisted of three concrete placement pours with the main concrete placement consisting of a 400-cubic yard mass pour. The project site was only accessible by barge.

The 4500 psi at 28-day strength concrete utilized a ternary mix design with cement, fly ash, and slag. A mid-range water reducer was also used to meet the desired workability and to achieve a maximum water-cement ratio of 0.41 with a maximum allowable shrinkage of 0.032%.

The concrete had a maximum allowable temperature of 72° degrees at the point of placement to help manage the heat of hydration and attendant volume to minimize cracking during the curing process.

With the use of two barges to transport three trucks at a time to and from the job site during each pour, coordination, and communication among the team were critical for the project's success.