Eafd stabilizer for returned concrete and mixer drum wash water

[0024]Concrete ingredients were mixed according to the standard ASTM C-192 “Standard Method of Making and Curing Concrete Test Specimens in the Laboratory.” The water-binder ratio of 0.52 and temperatures at 20±2° C. was maintained throughout. Initially, aggregates were added into a mixer together with absorption water. After a few revolutions of the mixer, the cement and the remaining mixing water were added. The mixer was run for about 3 minutes after all the ingredients were added, then left to rest for 3 minutes. Finally, the mixer was run for another 2 minutes.

[0025]To simulate the case of using EAFD as a stabilizer for concrete, the specified amount of EAFD was spread out over the concrete mixture, and the amount of water necessary to adjust the water-binder ratio was then added to the mixer. In the non-limiting exemplary embodiment, the amount of EAFD used was about 3% by weight of cement. The mixer was run for other 5 minutes. The fresh concrete was then discharged into wheel b