Our three year old loves books. He also loves trucks, ever since before he could talk. So naturally we have quite a few books featuring trucks in addition to all the truck artwork, toys, clothing and more. As much as I try, there's one little thing in them that I can't get over.
My college degree was in civil engineering. I never worked in the field, like my father did for decades, but I still know a thing or two. The example I'm leading to here is the difference between cement and concrete. Cement is glue, think rubber cement. It binds things together. Concrete is a combination of aggregate (rocks) and a cement, today typically Portland cement, that forms the hard substance used in construction, for sidewalks etc. Its ability to be poured and held in place until set has made it incredibly useful going back to antiquity.
Might as well include a few other tidbits I remember about concrete from school to establish my creds. Concrete can also include other materials like fly ash but we don't need to get too deep into materials. It's always getting harder as time passes, it doesn't stop after drying. The 28-day strength is the commonly used measuring stick to test concrete's strength. This is compressive strength, as the concrete is pushed (compressed) on both sides. Compression is where concrete excels and is remarkably strong. Its tensile strength (tension, pulled apart) is comparatively terrible, which is why steel bars ('rebar') can be added to create 'reinforced concrete' for concrete beams or foundations.
That's certainly more than you wanted to know. The point is cement and concrete are not the same thing. Though cement is used in concrete the terms are not interchangeable and they're used that way far too often. Day in and day out I see stuff like this in our kids books:
The top one is the worst offender. Come on Byron Barton. I don't know why the truck that mixes and keeps concrete from setting is apparently permanently named a 'cement mixer,' but that's what most instigated this post. For now, though that battle may be lost, I'm going to keep calling it a 'mixer truck,' at least until my kids can read for themselves. As much as the name of the truck is annoying, at least cement is going into the mixture inside.
Just get the name of what comes out of that truck correct. It's called concrete. Please.
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