All 40 statements in April's Pop Quiz are false. If you answered "true" to some (or even many) of them, please don't feel too badly. Though the wording was straightforward (I promised no tricks), many of the statements were chosen precisely because they are so generally accepted as being true—especially those concerning slump, shrinkage, cracking, and curling. Future columns will address many of these all-too-common fallacies in some detail, and hopefully will provide a much clearer understanding of what actually is happening. If you aced the test, congratulations! You may skip the next dozen or so installments. On the other hand, if your score was less than perfect, I think that you will find what comes next very interesting.


Allen Face is inventor of the Face Floor Profilograph, Dipstick, F-Meter, D-Meter, and Screed Rail. He is also an ACI Fellow and a long-time member of ACI Committees 302, 360, and 117.