Structural Concrete Repairs within Wet Wells at Indian Rock Dam

Description:

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Maverick was contracted to perform structural repairs to five concrete platforms within two 70 foot tall vertical wet wells at Indian Rock Dam. Access to the repairs was the main challenge on this project as they were located on the underside of the platforms within the wet wells and the only access point was via a two foot square opening in the floor at the top of the dam. In addition, all work within the wet wells was considered a permit confined space and the concrete repairs were performed in the winter months. Prior to starting work, an inspection was performed and the root cause for the spalled concrete was determined to be insufficient rebar coverage. Maverick worked with the Owner to develop a plan to bump out the forms to avoid premature failure of the new work.

Once mobilized to the site, the first step was to establish safe access into the wet wells. Temporary handrail was constructed around the access points and confined space/fall protection devices were setup. Crews then removed the existing ladder cages which enabled temporary work platforms to be erected beneath the concrete platforms. The next step was to demo the existing concrete with a 15lb electric chipping hammer and mechanically clean the rebar with a wire wheel. Forms were then fabricated followed by the placement of a bonding agent and high strength SIKA concrete. Since concrete was placed in the winter months, heaters were placed over each repair location and the concrete was allowed to cure for five days prior to removing the access platforms. All work was executed without any safety incidents.