Colorado D.O.T. – Central 70 Project

Summary Statement:

The Colorado D.O.T. specified EdenCrete® in the shotcrete in the Central 70 project, which completely reconstructs the re-envisioned I-70 corridor through north Denver.

CDOT’s Central 70 project calls for approximately 6000 yd³ of shotcrete containing EdenCrete® at ¼ gal/yd³. By using the EdenCrete® mix in place of the producer’s alternative 5000 psi shotcrete mix, the producer will require nearly 1,000,000 lbs less cement. This equates to approximately 32 fewer tankers of cement and 400 fewer tons of carbon dioxide released to the environment.

Use EdenCrete® to lower the CO2 footprint for your next project and leave a better environment for our children.

EdenCrete® Purpose:

EdenCrete® was used to optimize the original mix and reduce cement by 152 lbs per cubic yard of shotcrete. EdenCrete® also improved the rheology of the mix so that it could be pumped more easily, using lower hydraulic pressure and less fuel than what is required to pump traditional shotcrete.

Challenge:

Shotcrete is being used to reinforce new and existing caissons and abutments supporting the many bridge spans and elevated green spaces, as well as for the soil-nailed walls along new on and off ramps. The shotcrete mix needed to pump easily in order to keep up with the placement schedule while being extremely durable.

Specifications:

Concrete Producer
Aggregate Industries
Location/Date
Denver, CO
December 2018 start
December 2022 end
Contractors
KIEWIT and Thocron Shotcrete & Shoring
Volume & Dosage
~6000 yd³ of shotcrete containing EdenCrete® at ¼ gal/yd³

Project Details and Conclusions:

As the contractor, Thorcon Shotcrete & Shoring, began shooting the mix, the pump operator immediately commented on how well it was pumping compared to the original 5000 psi CDOT shotcrete mix. After a short conversation regarding improved rheology, the pump operator reduced the hydraulic pressure of the pump from ~3800 to ~2400 psi. The EdenCrete® mix pumped and stacked much better than the original mix, producing significantly less dust and waste from rebound. At the end of the first day, the Thorcon nozzleman commented “My shoes are clean!” The mix did not segregate or pack sand in the line, eliminating lost time to disconnect and clear the hose lines. Thorcon was very pleased with the EdenCrete® mix and has since adopted the EdenCrete® shotcrete mix as their standard shotcrete mix for the majority of their Colorado projects.