READY-MIXED CONCRETE TECHNOLOGY
Concrete mixed in a stationary mixer in a central batching and mixing plant and supplied in the fresh condition to the purchaser either at the site or in to the purchaser’s vehicles is known as ‘Ready Mixed Concrete”. The ingredients used for manufacturing Ready Mixed Concrete are Cement, Fine Aggregate (Sand), Coarse aggregates, Water, Mineral admixtures such as Pulverized Fuel Ash(PFA) / Ground Granulated Blast Furnace Slag(GGBS) / Silica Fume and Chemical admixtures. All the ingredients should confirm to the relevant IS codes.
The ingredients are batched and mixed in a centrally located computer controlled batching plant that monitors weigh-batching of the materials in accordance with the proportions of required Mix Design, with a batch size of one cubic meter. Manufacturing capacity of plant and the batch size vary from plant to plant. Each batch of ready mixed concrete is loaded into the Transit Mixers batch after batch. Generally, the capacity of a Transit Mixer is six cubic meters. Transit Mixers are trucks mounted with rotating/agitating drums used for transportation of ready mixed concrete to the construction site. All the raw materials used for producing ready mixed concrete are tested in the plant’s laboratory for physical and chemical properties in order to ascertain their suitability for use, in accordance with the relevant Indian Standards. Samples of ready mixed concrete are also drawn for carrying out required tests on workability with respect to slump, 7 days and 28 days compressive strengths etc.
At the construction site, the ready mixed concrete is pumped to the required floor or structure using pneumatic concrete pumps and pipe line. These pumps are capable of pumping concrete 100meters vertically and 300 meters horizontally.