Tables for Concrete Mix Proportioning.

Existing methods of selecting proportions for concrete usually offer tabulated values as guides in approaching the optimum amount of water, cement, and aggregates. For more accurate estimates, tables are presented in this paper which were developed recently for the State Highway Department of Alabama. One of these fables refers to the adjustments in water content for slump. In other tables, cement factors, in bags per cubic yard, are presented as a function of mix prqportion, grading, and average specific gravity of mineral aggregate. Further tables are offered to obtain the average specific gravity of mineral aggregate when a mixture of two materials of different specific gravities are used. Numerical examples illustrate the use of the tables pre-sented. While these tables are not a self-sufficient method of concrete mix proportioning, they will reduce the number of trial mixtures required. [ABSTRACT FROM AUTHOR]