Wednesday, July 23, 2008

Front row seats

Today seemed like a good day. I didn't have work to do, so both this morning and afternoon I was with the boys while Amy worked. "All day with boys" does not always equal "a good day" but things went smoothly.

This morning we had extended playtime in our basement family room which included the usual trucks, trains, and LEGOs. Lunch fell together as spaghetti with a tasty mixture of leftover homemade pizza sauce and toppings (getting to leftover scraps before they rot is always good). But the REAL fun came during lunch when the CONCRETE MIXING TRUCK pulled up in front of our next-door neighbors. This is a big deal in our house of boys! Our neighbor have been removing their front sidewalk for three days and we were expecting concrete. It seemed like too much to mix one wheelbarrow full at a time so truck seemed likely. We ditched the remainder of lunch to go sit in the shade about 10 meters from the chute as concrete was poured. We've read at least TWO books lately describing the process, including Tonka's "Working Hard with the Mighty Cement Mixer."

The truck's concrete drum was slowly spinning clockwise as the truck pulled up. We watched the truck operator assemble the chute by unfolding one section and hooking on another by hand. He then sped up the drum to mix the concrete really well (~.5 rot/sec, which is fast for a big heavy drum). Then he stopped the drum an spun it slowly counterclockwise until the concrete oozed out and slid down the chute. We've recently learned how spiral paddles mix the concrete when the drum spins one way and pushes it out when spinning the other. The concrete was unloaded one wheelbarrow at a time near the street and walked all the way to the top of the sidewalk to be dumped, about 5 or 6 meters. Every so often to operator took about 30 seconds to switch the direction of spin and mix the concrete some more to prevent it from setting up. It took much longer than expected and we were outside for over an hour. Finally the truck driver thoroughly washed down the chute and drum with a sprayer and drove off.

It was great fun! The man who was working with the concrete spent another 3-4 hours finishing the sidewalk. I was surprised that you could work with concrete for this long. I suspect it's like plaster, with different mixtures and working times, and the finishing pass needing to occur at just the right time. Tomorrow, a new sidewalk!


Geometricus said...

It's a day your boys will remember for years and years. Too bad the next-door neighbor wouldn't let your boys put their handprints in the freshly-poured sidewalk. That always makes memories last longer!

Dan said...

Well, I thought about it but while we're friendly with our neighbors, we're not buddy-buddy. They have two daughters and since it seem like they were signing I decided not to ask.