Thanks for Asking | November 26 2009

What is that white substance sprayed on the new concrete median on Clairemont Ave.?

Frank Smoot |

What is that white substance sloppily sprayed on some of the new concrete median work on Clairemont Ave.?

Thanks for asking! In concrete-aficionado terms, concrete can “spall” and “scale” – “break up” or “flake off” to you and me. While we think of concrete as tough stuff, road-salt and water take their tolls. But it’s a lot tougher if it’s “cured” right.

We couldn’t get hold of the state (why the state? see next question), but the city kindly offered a guess: “White Curing Compound.” Good for the concrete short-term and long-term.

Short-term, it helps the curing process three ways: first, it holds water inside so the concrete doesn’t dry before it cures; second, it reflects sunlight (being white), which keeps the concrete cooler and so (again) avoids drying before curing, and also helps avoid “thermal cracking” (concrete already heats as it cures and doesn’t need any help from the sun); third, it improves both the concrete’s compressive and tensile strength.

Long-term, the compound helps concrete resist corrosion by salt, and – in forming a harder surface – penetration by wet weather. Water expands when it freezes, and that, my friend, is one of the strongest molecular forces in nature. That pretty snowflake is better than a jackhammer.

By the way – pet-peeve alert – some people call concrete “cement” (which you didn’t, and thank you for that). Cement is an ingredient in concrete, just as flour is an ingredient in cake.


What happened to the “ghost bike” on the corner of Rudolph Road and Clairemont Avenue? It was placed to memorialize a teenage boy who was killed there last summer, but it disappeared a couple of months ago. Was it stolen?

The police department guessed that the bike’s owners reclaimed it. It wasn’t reported stolen, and the police did not remove it. The latter would not be EC police business anyway – although it would be on many other Eau Claire streets. While the city owns boulevards (more on that below), the state DOT owns the Clairemont right-of-way, since it’s technically a small portion of U.S. Highway 12. The county helps maintain it for the state.

Although it’s my understanding that the owner did in fact retrieve it, as the police guessed, it’s more complicated than that. The county removed it from the roadside. Such memorials – too-often needed, tragically – are a sensitive issue. And state, county, and city governments do have sympathy for them. On the other hand, they can’t let citizenry place permanent memorials on roadway verges. Some folks, for example, might want concrete or carved-stone monuments, ironically creating driving hazards. Following state mandate, the county removed it … after letting it linger a while, not only as a tribute, but as a good reminder about taking care. Then they held it, I understand, for the owner to claim.

Had this been a different street, the ECPD could have, by law, removed the bike. For years, city ordinance forbade anything but grass between your sidewalk and your street. (Many folks don’t know it, but the city owns our boulevards even though we care for them.) I’m thinking the reason is partly safety – more visibility at intersections – and partly fiscal: if the city ever needs to rip apart the boulevard for street maintenance or other, it doesn’t want to reimburse for whatever you’ve done to its property.

Quite a bit of discussion this past spring about what people could do on, and to, “their” boulevards. As far as I know, you can now plant flowers and bushes (with height restrictions), but ornaments of any kind are still banned on the boulevards.


Got a local question? Send it (17 S. Barstow St.) or email it (mail@volumeone.org) and Frank will answer it!  Frank has lived in Eau Claire for most of the past 41 years. He is an editor and researcher at the Chippewa Valley Museum, which is open all year just beyond the Paul Bunyan Camp Museum in beautiful Carson Park. You should go there.