Despite considerable evidence against the practice many specifications still rely on the slump test as an indication of workability. It has been said that the only thing a slump test really measures is the number of inches concrete will slump after a slump cone is lifted. Perhaps this is too sweeping. On a given job and with a given mix design, slump can be a valuable watchdog on variations occurring in the field; for example, variations in water content, absorption characteristics of aggregates, or gradation. But as a means of specifying or assessing workability the slump test is virtually useless. The slump test will be difficult to unseat, however. First, it has great acceptance among architects, engineers and contractors. Second, it is easy and economical; almost anyone can learn to conduct a slump test in a few minutes with just a low-cost slump cone and a bullet nose rod. Third, the results come out in nice, easy to understand inches. And finally, there can be a relation between workability and slump. When a contractor calls for a few more gallons of water in the concrete to improve the workability, the slump does go up. What's to take its place? The list of component characteristics should cover all the facets of workability; when all are specified and controlled, all aspects of workability should be satisfactory. Or course, when only certain characteristics are needed, it would be possible to specify controls over only those aspects of workability. One such approach to the problem has been forwarded by O. J. Uzomaka. He proposes an analogy with the science of soil mechanics, basing this on the theory that the concrete characteristics included in the term consistency are sufficient to describe the important factors bearing on the physical properties of a concrete mix called into play during the placing of plastic concrete. The three terms he uses to describe consistency are: compactability, the ease and amount of void reduction achievable; spreadability, the ease with which concrete spreads when subjected to vibration; and stability, the ability of concrete to remain homogeneous while it is being transported and placed. Tests are available to measure these characteristics: Glanville's compacting factor test; the Vebe test for spreadability; and Hughes' test for segregation.