Trade Journals for the Concrete Industry

Modern mixing plants are able to batch and document recipes entered or stored with great precision. From the archived batch records, it is possible at any time to verify that the mixing plant control unit has opened the batching outlets of the silos for aggregates, binders, admix- tures, additives, etc., and has subsequently delivered the correct amount of material from the respective silo to the weighing machine. However, to the present day one weak point in this scenario is not knowing for certain whether the right material is in the right silo. Especially with aggregates, which in some cases are delivered in significant quantities on a daily basis, it is always possible for the mixing engineer to release the wrong silo for the truck delivering the material. Mixing engineers have to control several mixing plants at the same time, and there will be distractions from phone calls, problems with bucket conveyors, requests for changes in production processes, visiting sales representatives, inventory control, etc. Because of this requirement to multitask, it can happen in exceptional cases that the mixing engineer, for instance, accidentally sets the rotary distributor at the top of the material silo of a tower system to the natural sand or some other cham- ber instead of the crushed sand chamber. The same can happen with the feed belts in a linear batching unit. A typical human error, without any intention of sabotage, and already the wrong aggregate material is in the wrong silo chamber.