Their are a variety of additives which may be added to cement.. These additives may be delivered to the rigsite as liquid or dry additives. The amount of additive is generally quoted as a percentage of the cement powder used. Since each sack of cement weighs 94 lbs, the amount of additive can be quoted in weight (lbs) rather than volume. This can then be related to the number of sacks of additive. The number of sacks of additive can be calculated from:

Number of sacks of additive = No. sxs Cement x % Additive

Weight of additive = No. sxs of Additive x 94(lb/sk)

The amount of additive is always based on the volume of cement to be used.