by Bill Palmer
Concrete and concrete construction, as I frequently note, have gotten more complex, more sophisticated, more technical. But an essential ingredient in working with all of these new innovations is an understanding of the basics. What do you think must be included as part of a person’s baseline knowledge of concrete?
Whenever I try to explain concrete to someone who knows only that their driveway is hard and gray, I start with the mix: cement, water, sand, gravel. Then I move into the simple, but poorly understood, concept of hydration—it doesn’t dry out to get hard! That leads to curing—we actually don’t even want it to dry out! Some people don’t believe that one.
At the World of Concrete, Terry Holland and Jeff Groom teach four three-hour classes on concrete basics. That’s a lot of basics and I’m sure they get much deeper into it than what I’m talking about. What they cover, though, is the right stuff: mixes, placement, finishing, curing, the effects of temperature, measurement of properties (both fresh and hardened), and durability.
That’s a good list, but what else would you include in trying to explain concrete to a novice? Say you hire someone and he or she knows nothing about concrete. What do they need to know to do the job?