2025 Award Winners and Nominees
Project Name
Babcock Street Outfall Project
Description
In December of 2020 it was determined that potential industrial contamination was seeping through a large, scoured out void of unknown volume around an Outfall structure along the Buffalo River. The area was near an industrial property that had shut down years ago. The current property owner was in a situation where they were being fined daily and was placed under a deadline to fill and seal off the void in an effort to curtail any further contamination seeping into the river by the end of the year. Failure to comply with the end of the year deadline would result in daily six figure monetary fines from regulatory agencies. In a collaboration between the Engineer, Contractor and Holcim GLE, a concrete solution was selected for the project. This collaboration resulted in the development of an Ultra-Lightweight Self consolidating mix design based on Holcim's Agileflow technology.
Evidence
Due to very soft soil conditions along the river bed the engineer specified a target unit weight for the Ultra Lightweight Agileflow of 85 lbs./cf. Though strength was not a concern, a minimum target strength of 200 psi was suggested for the material. Holcim developed a mix design using the Holcim Agileflow technology as a model incorporating Lightweight fines and low carbon cementitious materials which netted a Global Warming Potential of 215 kg/cy.
Sheet piling was placed along the riverbed to assist and help stabilize the riverbank and, help reduce the river current during placement. The void around the outfall structure was filled with 210 cubic yards of ULW-Agileflow at a 29" spread with a unit weight of 86 pcf. A concrete pump needle line was placed at the bottom of the void underwater. The void was determined to extend at least 18' back from the edge of the riverbank and the SCC principle of Agileflow was the only solution to fill the void. Water from the river was pump off the surface while the Self-Consolidating Ultra Lightweight Agileflow filled the void from the bottom up while flowing to the back of the irregular void space. The mix design was very cohesive and did not require any anti-washout admixture to reduce loss of paste volume underwater. The ULW-Agileflow had an ultimate strength at 56 days of 900 psi.
The overall performance of Holcim's Ultra-Lightweight Self Consolidating Agileflow proved to be an excellent solution that ultimately contributed to stopping environmental contamination of the river and helped prevent the owner from receiving significant environmental fines for non-compliance
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