Equipment World Digital Magazine
Issue link: http://read.dmtmag.com/i/674536
EquipmentWorld.com | May 2016 69 deck repairs in conjunction with installing a deck overlay, a CP system or an ECE treatment. Cyclical preventive maintenance is a system that schedules particular maintenance activities on a pre- determined basis. This would involve, for example, installing a bonded polymer overlay every 10 to 15 years, a rigid overlay like silica fume and latex modi- fied concrete every 20 to 25 years, or sealing concrete decks with a waterproofing penetrating sealant every 3 to 5 years. That sounds straight forward, but with thousands of bridges in some states a cyclical plan is sure to miss a few structures. So, preventative maintenance, as FHWA's definition of preservation points out, is of- ten condition-based, which means an issue is found through inspection. States have different preferred methods in their pres- ervation toolboxes, and what works well for one state may not hold up to conditions in another state. Indiana has recently adopted the practice of applying thin overlays, such as polymeric overlay materials, to be placed periodically. "Most of our preventive maintenance efforts have been focused around waterproofing and eliminat- ing bridge joints," says Jeremy Hunter, bridge design manager with the Indiana Department of Transporta- tion (INDOT). "Then, we try to waterproof the decks, whether it's polymeric overlays or another material. We're trying to start doing routine surface sealing on a cyclical basis of the bare concrete decks, and then also crack filling." Hunter feels the agency has made significant im- provements to their bridge decks using crack filling because of the frequency of crack shrinkage, even on new decks. "We haven't really had a good way to address that, because surface sealing is a part of every construc- tion contract that we do. But then we know that those Exposed rebar on the 4th Avenue Bridge between Camano Island, Washington, Stanwood, Washington and the I-5 corridor. Image: Washington State DOT