Rocky Reach Spillway Apron Underwater Concrete Repair
April , 2015
We were contracted to preform an underwater concrete repair to the spillway baffle under spill gate 3, and preform an inspection of the spill way and dentate from spillway 2-8 and 9-12. The spillway was separated into two sections by a fish ladder between Bays 8 and 9. The perimeter of the eroded areas were delineated using an U/W track creating a key way, ensuring a minimum depth of repair, throughout the area. Divers used rivet busters to remove concrete from the key cut as well as from under exposed rebar to ensure encapsulation and to allow couplers and new rebar to be added in areas wee eroded. Divers then used a 20k hydro blaster to wash away loose material and marine growth. Once the areas were prepared and cleaned, custom form tops were installed. The forms were made to fit the round side of the baffle that was approx. 18’x20′ and was rock anchored in place. Eight cubic yards of high strength concrete was then pumped into the form. While the concrete cured in the forms, the inspections were carried out of the stilling basin floor. The forms were removed and the project demobilized.