The 2nd Avenue utility upgrade work for the Mayo Clinic in Rochester, Minnesota, was completed in September 2023. PENETRON ADMIX SB, a crystalline concrete waterproofing admixture, was specified to protect the below-grade concrete tunnels and vaults from deterioration due to high groundwater levels.
Situated in the rolling bluff lands of southeastern Minnesota, just 90 minutes south of the Twin Cities of Minneapolis and St. Paul, Rochester is Minnesota's third-largest city with over 121,500 inhabitants – and home to the renowned Mayo Clinic.
First established in 1864 as a small private practice on the remote Minnesota prairie, the Mayo Clinic has evolved into an internationally recognized medical center. Today, the Mayo Clinic Hospital is a 2,059-bed teaching hospital that comprises the Saint Mary’s Campus with its Mayo Eugenio Litta Children's Hospital, as well as its Methodist Campus, forming an integral part of the Mayo Clinic academic medical center.
The 2nd Avenue utility infrastructure upgrade is part of the Discovery Walk project, a four-block landscaped road and utility reconstruction project that has transformed 2nd Avenue into a linear parkway directly adjacent to the Mayo Clinic campus in downtown Rochester.
“In addition to replacing and updating all of the sewers, the waterway, and water systems, this project also upgraded the Mayo Clinic’s utility infrastructure on 2nd Avenue, including the new steam tunnel and vaults,” adds Christopher Chen, Director of The Penetron Group.
Because of the subterranean location of the 2nd Avenue utility tunnels, a concrete waterproofing solution was specified by Burns & McDonnell, the structural engineer for the project, to protect the below-grade concrete structures – and the embedded reinforcement steel – from deterioration due to water penetration.
“A competitive product was originally specified for the concrete mix,” adds Christopher Chen. “However, after review by the engineer, PENETRON ADMIX SB, a crystalline waterproofing admixture, was subsequently approved for use.”
When PENETRON ADMIX SB is added to the concrete mix, it reduces permeability by generating a network of insoluble crystals that permanently seal microcracks, pores, and capillaries normally found in concrete. This effectively blocks water penetration, even under the hydrostatic pressure encountered at the 2nd Avenue construction site and prevents related concrete deterioration.
Jerid Ramaker, Superintendent at Knutson Construction Services, the 2nd Avenue project’s general contractor, noted: “Our placement team really liked using PENETRON ADMIX-treated concrete because of the factory-added green tracing agent (ed: a visible quality control measure). Seeing the green tint in the bleed water during placing and finishing gave us a certain peace of mind – we knew with PENETRON ADMIX SB in the concrete, the concrete structure was now permanently protected from water intrusion.”
