Use wooden or steel measurement boxes of size 350 x 250 x 400 mm(35 Liters) to measure the volumes of cement, sand and aggregates for preparing the concrete mix. This box can contain 1 bag of cement weighing 50 Kg. Materials should be loosely filled in box while batching. For Example, to prepare M20 (1:5:3 approx.) mix of concrete, you require one bag of cement, 1.5boxes of sand, 3 boxes of stone aggregates and 21 liters of water.