Some fallacies in cement testing

In these days the testing of cement is no longer exclusively in the hands of the expert, but almost every user of cement in any quantity now carries out his own tests on the material he buys; or has such tests made for him by his own staff. In some instances this has meant that the cement is judged on results obtained by very inexperienced persons. It may be an excellent thing, from the users' point of view, to test his own supplies, but there is a danger that the practice may lead to numerous unfounded complaints and disputes as to the quality of those supplies. W. Laurence Gadd