CSA Cement vs Accelerators in Concrete Countertop Mixes

A student asked me a question recently:

What’s the difference between CSA cements and accelerators? Don’t they both make the concrete cure faster?

The answer is no.

Accelerators don’t speed up strength gain, only set time. This means that concrete made with or without an accelerator will have developed the same 28-day strength at the same rate. The concrete with the accelerator just sets up faster so that it can be troweled or finished earlier.

CSA cements, on the other hand, actually speed up strength gain. They speed up strength gain so much that the concrete is as strong after 28 hours as it would have been in 28 days with portland cement! Plus CSA cements have a host of other benefits, such as elimination of efflorescence and reduction of carbon emissions.