Experimental study on the application of zero discharge of wastewater from ready-mixed concrete production.

To realize the resource utilization of zero-discharge production wastewater from the ready-mixed concrete mixing plant, this experiment combined the microstructure detection techniques of the mercury-pressure method, scanning electron microscope, and X-ray diffraction to investigate the role and influence law of wastewater admixture and its storage time on the mechanical properties and microstructure of concrete. The results showed that the 7-day compressive strength of mortar with 100% wastewater admixture increased by 35% and the 28-day compressive strength increased by 16% compared with that of ordinary mortar, while the compressive strength of specimens with other wastewater admixtures increased to a certain extent; the alkaline environment provided by wastewater was beneficial to promote the hydration reaction of cement. The micro-particles contained in the wastewater of ready-mixed concrete production play a filling and bonding role in the microstructure of concrete and improve the compactness of concrete. [ABSTRACT FROM AUTHOR]