Dive Brief:
- A report from Great Hall Partners, the Ferrovial-led consortium performing the $650 million renovation of Denver International Airport’s Jeppesen Terminal, indicates that the project is 10 months behind schedule, a delay that includes the impact of deficiencies in the structure’s existing concrete.
- In its "Great Hall Project: December Construction Project Report,” the group said testing of existing concrete revealed that the compressive strength in some areas was lower than airport officials specified in the development agreement. Some samples also showed that the concrete could be susceptible to alkali-silica reaction (ASR), a chemical reaction that can compromise integrity, but the report noted that the 25-year-old concrete does not show signs of ASR.
- The consortium officials said there was no way to estimate how the concrete issues would ultimately affect the schedule until they evaluate additional test results, expected in April, according to a CBS 4 Denver report. Great Hall Partners did say in its report, however, that the concrete problems have slowed some construction activities like steel erection.
Dive Insight:
The Denver City Council inked a $1.8 billion deal with Great Hall Partners in August 2017 for the airport renovation, which also includes a 34-year concession management contract. This is the first major public-private partnership for a city-owned property in Denver and is expected to increase the airport’s capacity to 80 million passengers per year.
Concrete’s compressive strength is important to know because, in projects like the Jeppesen Terminal, it must be able to support steel and structures built on top of it. If the compressive strength continues to be an issue, the P3 could suggest workarounds like slight alterations in design, although it's not clear if a fix is even necessary at this point.
The Denver airport has had run-ins with ASR on its runways and replaced about $10.6 million of concrete slabs in 2007. However, other factors, like the freeze-thaw cycle and deicing agents, were thought to have contributed to the deterioration as well.
Deficient concrete panels discovered during construction of the Washington, D.C., Metrorail’s $5.8 billion Silver Line extension resulted in the replacement of 115 concrete panels and the treatment of approximately 1,700 others with a special coating to prevent water intrusion and a reduced life span. Investigators, with the assistance of a whistleblower, found that a former employee of the manufacturer, Universal Concrete Products, falsified test results to make it appear as though the panels met specifications. The U.S. Department of Justice recently reached a $1 million settlement with Universal and company executives to settle civil allegations in the matter.
