Post-Tensioning Techniques Anchor New Bridges at I-435 & I-70 Interchange
The Emery Sapp & Sons (ESS) team is constantly looking for ways to use industry-leading techniques and advanced methods to construct best-in-class infrastructure. One of these techniques is post-tensioning pier caps, a method of testing and reinforcing concrete structures. This technique positions post-tensioning tendons, which are prestressing steel cables inside plastic ducts or sleeves, in the forms before the concrete is placed. After the concrete has gained strength, and before the service loads are applied, the cables are pulled tight – or tensioned – and anchored against the outer edges of the concrete.
Our teams are currently using this reinforcement technique on the I-435 and I-70 Interchange project in Kansas City, Missouri. “When we bid this job and were awarded the contract, the plans called for the post tensioning of the straddle bent. This exact technique is not something ESS has done before, and I’ve only done it once in my entire career. We reached out to the experts at DYWIDAG-Systems International Group to come help us,” said Brent Ponder, bridge and structures manager.
DYWIDAG supplies innovative products and solutions to the construction industry. We utilized their Post-Tensioning System. This system provides durability, safety, quality and reliability and was tailored to our specific project requirements. For this project, the post-tensioning process took about a week. Our teams worked hand-in-hand with a DYWIDAG systems specialist from their Chicago office to help facilitate this rare task.
“In the midwest, you don’t typically see a lot of post tensioning on bridge structures of this size. In this case, it was unique because of the design. The pier cap was poured monolithic with the deck, and then we post-tensioned afterwards,” explained Ponder.
Selected to build the I-435 & I-70 Interchange project for the Missouri Department of Transportation (MoDOT), our teams have been challenged to replace the bridges within the interchange and concurrently construct a brand new interchange in a partial turbine design. This new interchange will enhance the safety within the densely-travelled Kansas City Chiefs and Kansas City Royals stadium corridor. The project includes full bridge replacements, removal of left exits, improvements to loop ramp configuration and congestion relief.
ESS began this project in March of 2019 and are scheduled to be completed by December of 2020.