Proportioning of Plain Cement Concrete The proportioning is done based on the requirement or given specification. Generally 1:2:4 or 1:3:6 mix is used. The measurement of material can be done by weight batching or volume batching. In volume batching, coarse aggregate and sand shall be measured by measuring box of 30cmx30cmx38cm of a suitable size equivalent to one bag cement of 1/30 m3or 0.035 m3. Sand shall be measured on the basis of its dry volume. While measuring the aggregate, sacking, ramming or hammering shall not be done. Mixing of Plain Cement Concrete Mixing of PCC can be done either manually or by the means of machines : Hand Mixing PCC is allowed to be done by hand-mixing only for small-scale works. The base on which the concrete is mixed must be clean, watertight slab or a steel platform. Sand and cement are mixed thoroughly followed with the addition of coarse aggregate. Lastly, water is added and the mixture is mixed properly to gain an even colour and consistency. Machine Mixing A measured quantity of dry coarse aggregate, fine aggregate and cement shall be placed in their respective hoppers. The dry materials shall be mixed in the mixing drum for at least four turns of the drum after which the correct quantity of water shall be added gradually while the drum is in motion. The total quantity of water for the mixing shall be introduced before 25% of the mixing time has elapsed and shall be regulated to achieve the specific water-cement ratio. The mixing shall be thorough to have a plastic mix of uniform colour.