Research geologist (engineering petrography); chief, U.S. Army Engineer Waterways Experiment Station, Jackson, Miss.
Pages: 19 Published: Jan 1966
Petrography is the scientific description of the formation and composition of rock, including the systematic classification of rocks. Petrographic examination of hardened concrete—a man-made rock —is the examination of concrete by the techniques used in petrography, to determine the formation and composition of the concrete and to classify it as to its type, condition, and serviceability. This paper is intended to show that Petrographic examination provides information useful in evaluating hardened concrete, to note the problems inherent in its use, to outline what it involves, to describe the kinds of information that it can produce, and to show how this information can be applied. The questions that materials testing and evaluation tries to answer are: (a) “How will this material behave in use?” or (b) “Why did this material behave in use in the way it did?” The first question is never unequivocally answered except after-the-fact, by determining how the material did behave in use. The most useful method for developing practical information upon which to make decisions that depend on prediction of probable behavior of materials is the study of why materials behaved in use as they did.
Paper ID: STP49871S