DENVER — The $650 million renovation project at the terminal of Denver International Airport that was supposed to take 3 years may not be completed until 2023.

A new report from Great Hall Partners says issues with the concrete floor could delay the project for 18 months.

DIA originally said the terminal renovations would be done by November 2021. Two months ago, the developer said it may be more like August 2022. Now, the construction may not wrap up until May 2023.

RELATED: The $650 million renovation project at DIA could face a 10-month delay

The report shared concerns the weaker-than-anticipated concrete could push back future phases when crews need to start erecting steel on the Jeppesen Terminal floor.

After testing about half of the concrete samples last fall, the report said some of the concrete extracted from the floor had lower ‘compressive strength’ results, or ability to withstand heavy loads without breaking, than the airport planned. Approximately 94 percent of the concrete cores were tested when the report was issued, according to Great Hall Partners.

The current delay timeline is based on estimates DIA received from the contractor working on the project.  

DIA said the current timeline is an estimate and they are working on mitigation efforts to decrease the delay. 

The report also says it is not clear yet what impact this delay will have on the overall project timeline or the budget. 

Work on the Jeppesen Terminal began last summer. When construction is complete, the terminal will look completely different and the concourses will have new gates.

RELATED: Here's what DIA will look like after its $2 billion renovation

The renovation is part of a $1.8 billion deal with Spain’s Ferrovial S.A. Denver City Council signed a 34-year contract with the private company in August 2017.

RELATED: DIA's $1.8 billion overhaul is a go

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