A concrete accelerator is an admixture for the use in concrete. The addition of an accelerator speeds the setting time and this makes the cure time start earlier. For someone working out of town or wanting to finish a job quickly this product does just that …it saves time and money on hours waiting for concrete to cure out. A huge benefit to some one wanting to set post and finish the job the same day they started. You can set your post in the morn’n and go to lunch and come back and work on your job in the afternoon.