Head, Petrographic Laboratory, Bureau of Reclamation, Denver, Colo.
Pages: 21 Published: Jan 1956
Petrographic examination of concrete aggregate is visual examination and analysis of the material in terms of both lithology and properties of the individual particles. The procedure requires use of a hand lens and petrographie and stereo-scopic microscopes; less commonly, X-ray diffraction or differential thermal analysis is a necessary part of the procedure. By petrographie examination, the relative abundance of specific types of rocks and minerals is established; the physical and chemical attributes of each, such as particle shape, surface texture, pore characteristics, hardness, and potential alkali reactivity, are described; coatings are identified and described; and the presence of contaminating substances is determined.
Paper ID: STP39438S