Relational mix maintenance (by Mark Mackenzie)
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Figure 5.10 Relational mix maintenance – main menu.
The system addresses and makes use of familiar and recognisable key design criteria and factors, these are shown in the main menu (Fig. 5.10) and include: ●
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Raw Material Data – A comprehensive list of all materials allocated to a plant including ‘Available Materials’ – those currently in use in the plant, ‘Unavailable Materials’ – those allocated but not currently in use. Data includes all required codes and descriptions, costs, units of purchase and batch; specific gravity etc. (linked to ConAd – Raw Material Data); batching sequences – primary & secondary; scale allocation, details regarding method of batching – automated or manual. Cementitious Efficiencies – The primary cement (GP/OPC, etc.) is assumed to have an efficiency of 1.0 for all grades and other cementitious materials are allocated efficiencies relative to the efficiency of the primary cement. A cementitious efficiency is calculated for each characteristic strength in each blend i.e. we have found that efficiency varies over the strength range. The relative cementitious efficiencies of each blend are used in the algorithm which adjusts the W/C ratio when creating related mix designs. Blends/Tapers (i.e. variation over ranges of mixes) – This includes cementitious blends; coarse aggregate blends; fine aggregate blends; water blends and air %. With the exception of coarse aggregate blends, all blends/tapers can be varied