Curbs along Second Avenue and Main Street less than two years old already are showing signs of wear, including numerous gouges possibly caused by snow-moving equipment.

The severity of the problem this week seemed to hinge on who was asked.

Chuck Correa, a regional preconstruction engineer for the state Department of Transportation, viewed photos of some of the damage this week. Correa said the state uses “air-entrained concrete,” a chemical additive that adds bubbles to the mixture, allowing for expansion and contraction and making concrete more resilient to freeze-thaw cycles.

“Just because a curb is scuffed doesn’t mean it’s more prone to deterioration in the future. Having the face scuffed off them won’t necessarily advance further deterioration,” Correa said. “We wouldn’t expect there to be continued degradation of curbs unless they keep getting hit again.”

Correa said a crack that goes through a curb will accelerate decay, as will application of salt in the first few years after concrete is poured. “A crack that goes all the way through, that’s a path for water to get behind it and start jacking it around in the freeze-thaw cycle,” he said.

He said the state tries to discourage property owners from using salt as a de-icer in the first year after construction. “It’s more susceptible to chemical reactions when it’s younger.”

Matt Boron, foreman of DOT’s local road crew, said curb gouges are typically created by the edge of grader blades. A grader – instead of a plow truck – is used downtown and in other areas where snow must be removed instead of plowed off the roadside into an adjacent shoulder or ditch. Plow trucks are equipped with rounded “wear strips” that bolt to the edge of blades and help plows bounce off curbs instead of digging into them, he said.

Boron, who drives the grader, said he has tried to be careful around new curbing, but heavy snows here conceal curb edges and wet snow can push a 40-ton grader from side to side. “To know exactly where that blade is – to the inch – is tough.”

Plow damage is an issue statewide, evident in median strips and gutters in cities like Juneau and Ketchikan, he said. “We deal with plow damage across the entire road system. There’s a fine line between making the road safe for the public and digging into the asphalt or gouging into the curb.”

Boron said if moisture can find a hole to sit in, it will freeze and expand, causing a larger hole. Potholes can start as tiny holes in a roadway, he said. “Water damage is why we have road maintenance,” he said.

Dave Stickler, who owns the concrete company that’s built sidewalks around Haines, said he’s frustrated to see the pace of deterioration of his company’s work. “It’s really a shame, all that brand new sidewalk is already smashed… From a contractor’s point of view, it’s job security, but as a taxpayer, it’s frustrating. It costs a lot of money.”

Stickler said gouges in cement expose material that’s more porous than a sidewalk’s slick finish, accelerating deterioration.

He said the state needs to affix a type of “roller” to the edge of grader blades to help preserve curbs. Even if attaching such a device took 20 minutes, it would still save the state money, he said.

Stickler also said he has an issue with a sidewalk design that includes expansion gaps that run parallel to the roadway. Sidewalks that are only four feet wide don’t contract and expand enough to warrant the gaps, which trap dirt and moisture and foster growth of grass that undermines curbs, he said. The state has stopped using the parallel gaps in Juneau, he said.

DOT’s Correa said slab cement, such as a poured floor, can last 100 years or more, but a sidewalk and curbing see a lot more wear and last about 30 years. That’s about the same lifespan as a road surface, which explains why the state typically replaces sidewalks and curbs when it’s resurfacing roads.

Work to build only sidewalks and curbs, such as along Old Haines Highway this summer, is atypical, he said.