Progress continues on K's garage, the posting on FB this morning was watching cement dry. I couldn't help myself, I was once referred to the concrete industry counsel reeducation program for blatant misuse of cement.
If your cement dries, before it cures, you have a problem. Water mixed with Portland cement, causes a chemical reaction that causes the cement to "cure' or harden. Cement, is mixed with aggregate, generally crushed or size sorted rock, to form concrete. What K was watching was concrete curing. It will cure underwater, but if it dries before it cures it will never reach it's full hardness.
Next lesson is cinder blocks versus concrete blocks. Cinder blocks are made with "cinders" traditionally the incombustible left overs from burning coal. Cinder blocks are kind of like popcorn glued together. The are lite weight, brittle and have limited weight bearing capacity. Concrete blocks are made from Portland cement and aggregate. Concrete blocks are heavy, have a high tensile strength and can bear significant weight. Cinder blocks are used for non-structural infill such as partition walls, Concrete blocks are used in foundations, structural walls, in applications where the finished wall is exposed, and in weight bearing applications. Cinder blocks are in inferior substitute.
The Concrete Industry Council is very protective of the name and reacts unkindly to miss characterization of the product they are so proud of. Apparently their reeducation program was very successful. If we could only reeducate the drivers in this town as effectively.