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Both the vortex slurry mixer and the twin-shaft mixer offer reduced mixing time, improved concrete homogeneity and improved dust control, the latter because wet mix components are blended with dry ones before dispensing. The vortex slurry mixer has only one internal moving part, an impeller, and works much like a household blender. It also offers the advantage of material weighing. Batch water is weighed (instead of metered) into the mixer's cone-shaped vessel. While dry cementitious ingredients are batched, the impeller creates a vortex in the batched water. The unit then weighs and blends cementitious materials into the water vortex, reportedly producing a more uniform, homogenous slurry than other mixing technologies. Then the batch operator incorporates admixtures into the slurry. A twin-shaft mixer is a high-intensity, heavy-duty mixing unit that thoroughly blends concrete mixes with slumps of 0 to 6 inches. Unlike a slurry mixer, these mixers blend both slurry and aggregates before loading into trucks. The mixer's two horizontal synchronized shafts with attached paddles rotate in opposite directions at high intensity. One paddle forces concrete onto the paddle on the shaft directly opposite, creating an aggressive shearing pattern. This high- intensity mixing coats aggregates with slurry and thoroughly disperses color and admixtures. keywords: vortex, twin-shaft, slurry mixer, transit mix