Cement Mortar
The unit of measurement for cement is a bag of cement weighing 50 kg and this is taken as 0.035 cu. m. Sand is measured in boxes of size 25x35x40 cm on the basis of its dry volume.
Cement mortar shall be used as soon as possible after mixing and before it has begun to set, (and in any case within two hours, after water has been added to the dry mix), only that quantity of mortar which can be used within 30 minutes of its mixing shall be prepared at any time, care shall be taken not to add more water to the mixing than which shall bring the cement mortar to the consistency of a stiff paste,
In case cement mortar has stiffened because of evaporation of water, it may be retampered by adding water frequently as needed to restore the requirements of consistency, but this retampering shall be permitted only up to two hours.