• HHCW was efficiently treated into HHCWS by multiple wet-grinding. • The filling effect of HHCWS was proved in the durability of cement mortar. • The compressive strength of concrete with HHCWS of 10% was not decreased. • Utilization of HHCWS can bring significant economic and environmental benefits. To effectively eliminate waste and reduce cost, the humid hardened concrete waste (HHCW) from ready-mixed concrete production was used to produce slurry mineral admixture that was utilized in concrete by the treatment of multiple wet-grinding. The particle size distribution, morphology, liquid phase, and mineral composition of humid hardened concrete waste slurry (HHCWS) were tested. The median particle size of HHCW was reduced to 26.5 μm from bulks by initial wet-grinding and then to 1.28 μm (60 min) again by a secondary one, indicating that multiple wet-grinding was very propitious to refine HHCW. Both the electrical conductivity and pH value of the HHCWS were improved because of the increase of Ca 2+ and OH - in the slurry. Three fineness (D50 = 26.5 μm, 5.71 μm, and 2.52 μm) and three dosages (5%, 10%, and 15%) of HHCWS were investigated comparatively to replace the cement in concrete or mortar. The experiment group with the HHCWS of 2.52 μm at the dosage of 10% had basically the equivalent compressive strength of the control group in C30 and C45 concrete and showed positive performance on the durability in mortar system, such as autogenous shrinkage, chloride ion permeability, and carbonization resistance. Based on benefit evaluation, multiple wet-grinding could reconcile economic feasibility with an environmental benefit and was an innovative approach to the utilization of humid hardened concrete.