Hand mixing is adopted for small works and where the quantity of concrete used is small. The following procedure is followed to mix concrete by hand.
Construct a platform of bricks, lean concrete or iron sheets of a size as per requirement of the volume of concrete to be mixed.
Spread out the measured quantity of sand uniformly on the mixing surface. Dump the cement on the sand and distribute it uniformly. Mix the sand and cement with the shovels, turning the mixture over and over again until it is uniform in colour.
Spread out the sand-cement mixture once again uniformly on the mixing surface. On top of this, spread the measured quantity of coarse aggregate. Don’t dump at one place, otherwise the bigger particles will tend to roll out. Mix again atleast three times by shoveling from the centre to side, then back to the centre and again to the side.
Make a hollow in the middle of the mixed pile and pour slowly into half to three-quarters of the total quantity of water required. While the material is turned in towards the centre with shovels, add the remainder of the water slowly, turning the mixture over and again until the colour and consistency are uniform throughout the pile. This will indicate that all ingredients are thoroughly combined. The water should be poured slowly into the mix. This is best done by means of a gardener’s water can fitted with a rose-head. Throwing water from a bucket all at a time will result in its running away and taking cement with it.
Time of mixing does not exceed 3 minutes
Mixing platform is cleaned at the end of the day’s work, so that it is ready for use the next day.