MdTA Addresses Bridge’s Cracking Concrete

Fri March 11, 2005 - Northeast Edition
Brenda Ruggiero

The Maryland Transportation Authority (MdTA) is working to correct a snag in its four-year project at the William Preston Lane Jr. Memorial (Bay) Bridge, which crosses the Chesapeake Bay on Maryland’s eastern shore and involves Routes 50 and 301.

The project, which was originally estimated to cost $60 million, involves rebuilding the westbound deck of the bridge. However, it was determined this past fall that more than half of the resurfacing work needed to be redone because of cracks in the concrete.

In the original announcement from MdTA, executive secretary Thomas L. Osborne Sr. stated that correcting the work would add more traffic delays and raise the cost by at least $7 million. However, he noted that the problems affected only the durability of the bridge, not the safety.

According to Robert L. Flanagan, who is transportation secretary and MdTA chairman, 52 percent of the new top layer did not properly adhere to the underlying concrete layer. This portion of the work represents approximately 10 percent of the overall deck reconstruction project.

The MdTA is working together with the prime contractor for the project, Cianbro, which is based in Pittsfield, ME, but also has regional offices in Baltimore.

A task force was assigned to investigate the issue and determine how the mistakes happened and who is responsible. Their final report was submitted on Feb. 9. It named six factors that the Overview Team believed contributed to the failure of the concrete used to re-surface portions of the westbound span.

They included:

• Thin decks on the Bay Bridge;

• Inadequate preparation of the substrate surface;

• Use of matrix restorer and epoxy bonding agent on the substrate;

• Properties of the concrete mixtures itself;

• Cold temperatures in which much of the concrete was placed; and

• Inadequate curing methods used.

The report did not assess blame, but noted that the overall work failed to meet the “stringent demands” of the project.

Mike Hart, Cianbro’s Mid-Atlantic regional vice president, held a news conference on Feb. 17, to answer questions regarding the project. He thanked the Overview Team for their independent report outlining the challenges surrounding the resurfacing, and also affirmed Cianbro’s commitment to work with the MdTA and its engineer to complete Phase I of the project.

“Cianbro represents the public process,” he said. “Our company currently operates up and down the eastern seaboard. We have over 2,000 employee-owners and we are dedicated to open communication. We also believe in teamwork. This is a complex project and a very challenging situation. Everyone involved — the owner, engineer, and contractor — has worked in good faith to produce a quality project with the safety of both the traveling pubic and the project team as a priority. Together, we all want the best and most cost-effective solution.”

Hart went on to say that the company respects the Overview Team and the review process. He stressed that Cianbro performed all work per the specifications of the contract and under the direction and approval of the MdTA.

“In general, we agree with the report,” Hart noted, “but feel it is important to clarify some issues in the report. We believe the best approach … is to review the six factors that the Overview Team feels contributed to the failure of concrete used to resurface portions of the westbound span.”

Hart then went through each issue listed on the report and clarified the company’s experience with each.

“The initial application for the matrix restorer and epoxy bonding agent on the substrate concrete was performed per specifications of the contract and under the direction and approval of the MdTA,” Hart noted.

“Prior to the start of any overlay work, on January 22, 2002, Cianbro and our subcontractor [Pioneer Construction Company Inc.] communicated to the MdTA that the specified matrix restorer was not appropriate. In fact, it was acting as a bond breaker, not a bond restorer. Over the next several months, Cianbro repeatedly communicated this concern, yet no action was taken by the MdTA.

“After repeated requests, the MdTA agreed and allowed Cianbro to perform core sampling of the completed deck to determine if the matrix restorer was performing as intended in the original specification and design. On May 12, 2003, the MdTA directed Cianbro to discontinue the use of the matrix restorer because Cianbro’s and Pioneer’s concerns were validated by the MdTA’s testing.”

The state reportedly covered the initial cost of repairs, but the MdTA is working with the state Attorney General’s Office to determine the degree to which MdTA, the construction contractors, and the engineering contractors are responsible for the deterioration.

The original two-lane bridge over the Chesapeake Bay was built in 1952. The current westbound Bay Bridge complements the original, and involves three lanes of traffic. The 4-mi. bridge opened to traffic in 1973, and is 38 ft. wide. It involves five different types of structural components, including pre-stressed concrete beams, steel girders, two steel trusses, a three-span suspension unit, and a three-span steel through truss unit. The entire length of the bridge includes 122 spans.

The deck renovation project involves resurfacing and complete replacement, and was proposed in the late 1990s when the original reinforced concrete deck began to exhibit deterioration. Work began in January 2002.

Problems with the project first surfaced in December 2003, when construction inspectors identified random, isolated cracking in the deck. In March 2004, the consulting firm of O’Connell and Lawrence Inc. (OC&L) was contracted to perform an independent investigation regarding the cracking problem. Initial findings were submitted to MdTA in June 2004, and the Preliminary Report of Findings was submitted in September.

The second phase of the project has been delayed until at least the fall of 2006. CEG