Vice president, research and development, Martin Marietta, Cleveland, Ohio
Pages: 34 Published: Jan 1978
Petrographic examination of concrete aggregate is visual examination and analysis in terms of both lithology and properties of the individual particles. The procedure requires use of a hand lens and petrographic and stereoscopic microscopes; less commonly, X-ray diffraction, differential thermal analysis, or electron microscopy is used to supplement the examination with optical microscopes. By petrographic 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: STP35633S