Concrete Compressive Strength Predictions

[dleonard]

I am wondering if anyone knows how to predict the 28 day compressive strength of concrete, without using a 7 or 14 day break to guide you along. I am most interested in trying to use differential equations to model the behavior of concrete as several variables change from batch to batch. The variables I am most interested in are slump, air entrainment and the temperature of the mix.

 

[dirtsqueezer]

There are so many variables, dleonard, I think this would be an exercise in futility. Consider first the aggregate. In order to have good compressive strength strength, one must have competent aggregate. There is a soundness test, gradation, possibly LA abrasion, clay content, elongate particles...you get the idea- there are just so many possible variables. Not to mention the water content, type of cement...egads.
On the other hand, , I had an...associate, that over the course of a summer tracked exactly the variables you speak of v. compressive strength on one project with a single supplier. I don't remember the specifics, but I do believe there were some general trends. I could get you in touch with him. A good general rule is higher air, lower compressive strength- the others I could only guess. Let me know if you're interested. These would be, of course, for only one plant and one locality. I remember thinking at the time that it was, if nothing else, extremely good record-keeping.