Holcim (New Zealand) Ltd - How we make concrete

Cement - cement is stored on the concrete plant in silos;
Aggregate & sands - are materials required for concrete production, and include coarse aggregate (about 5, 10 and 20 mm size), fine aggregate (such as “beach” or “pit” sands) and special chemicals (admixtures), which are also stored in silos and tanks on the concrete plant;
Weigh hopper - the batching process (selecting proportions of each raw material so that the customer gets the mix they need) is almost always computer controlled in bigger plants;
Mixer - all the materials are accurately pre-weighed prior to being fed into the plant mixer, or transit mixer (concrete truck bowl) where it is agitated for a set period of time to ensure thorough mixing of materials;
Concrete delivery - concrete is fed into the bowl of the truck. It is then delivered to the customer. Discharge of the concrete can be off the shute of the truck, barrowed or pumped to the final location.