As Denver International Airport waits for an assessment of weak concrete in the terminal to wrap up, its contractors are delivering increasingly startling forecasts of the potential impact on a renovation project’s timeline. May 2023 is the most recent projection made by Great Hall Partners for completion of the final phase of the $650 million-plus project, as disclosed this week in a monthly project report for bondholders. That would be 18 months beyond the original target of November 2021.