poor concrete mix

Ratio adverse pressure gradient concrete block machine in a large place, moisture will penetrate through the aggregate gap, so that aggregate coalescence caused by blocked tubes, occurs in pipe bends, reducers and piping arrangement of hoses at the middle; another concrete water-cement ratio is too large, easy to segregation, resulting in separation of mortar and aggregate plugging, more common in long-distance pumping level when "segregation" blocking pipes and piping down steel cement silo end of the vertical segregation plugging. Too little amount of cement and sand ratio is too low, poor workability of concrete, deformation difficulty increases friction in the pipe, easily plugging. Concrete slump is too low (80mm less), the pumping resistance was significantly increased, so pumping impossible.