Concrete Repair in Stillwater, Minnesota.

Stillwater runs a sidewalk rehabilitation project and splits it down the middle, half from city funds and half assessed to the adjacent property owners. A walk goes on that list when it is severely cracked, raised, settled or misaligned enough to be a tripping hazard. The city has had properties appraised to compare the estimated assessments against the benefit the work is judged to add. Downtown is where the walk frontage is, with a public ramp a block west of Main Street and roughly 760 surface spaces mostly along the river, and the rest of the commercial concrete is out on the Highway 36 side at Market Drive and around Lakeview Hospital on Churchill Street West.

Four things take concrete apart here, and each one goes after a different part of a property. A sidewalk panel sits on saturated ground or over a root. The water under it freezes, expands and lifts the panel. In spring the ground thaws and settles, and the panel does not go all the way back down with it, so what was flush in October is a lip in April. Then a plow blade catches that lip every storm for five months and breaks the leading edge off it. A curb takes the plow head on. The blade rides up the gutter, catches the curb face and takes the nose off in chunks. Salted slush sits in the gutter longer than anywhere else on the lot, because the gutter is where everything on the lot drains to, so the gutter is where the surface scales first. De-icer does the same thing to flat concrete. Chloride pulls water into the surface and runs more freeze and thaw cycles through it in a season than the weather would on its own. The mortar skin comes off in flakes and the aggregate stands proud. The approach at the street is a joint between two slabs that belong to different people. The street sits on a road section and a deep base; the drive sits on whatever was there. Frost gets under the shallower one first, the apron cracks along the gutter line, and that crack takes water into the base under both of them.