Petrography Subcommittee at Work on Proposed Guide for Scanning Electron Microscopy
Subcommittee C09.65 on Petrography is currently in the final stages of completing a proposed new standard, WK17049, Guide for Scanning Electron Microscopy (SEM) Analysis. The subcommittee is part of ASTM International Committee C09 on Concrete and Concrete Aggregates.
During the past several decades, methods and techniques for SEM and accessories such as energy dispersive X-ray spectroscopy (EDS) have been used to identify constituents and characterize microstructures in concrete. In addition to providing visual images, SEM/EDS instruments provide elemental analysis capabilities that have proven useful in identifying specific constituents in concrete and aggregates. The information contained in WK17049 is intended to complement other techniques that are used to analyze concrete and aggregates, such as wet and instrumental chemical methods, as well as other conventional and specialized types of microscopy.
WK17049 will provide a technical resource that outlines specific recommendations for applying SEM/EDS techniques to the examination of concrete as discussed in ASTM standard C856, Practice for Petrographic Examination of Hardened Concrete. Currently, the use of SEM/EDS is listed as one of a number of microscopy techniques that can be used during the examination of concrete. However, there are no specific recommendations or discussion of techniques in C856 regarding application of SEM/EDS to the examination and analysis of concrete and aggregates.
When adopted, the proposed standard will provide guidance on qualification recommendations, equipment functions, specimen preparation, recognition of microstructural features and discussion of analytical techniques that may be used to aid in the identification and characterization of concrete and aggregate constituents that directly or indirectly impact concrete performance.
WK17049 will also serve as a basis for concrete technologists and engineers to expand their knowledge and understanding of SEM/EDS techniques that have proven useful during petrographic examination of concrete and aggregates.
To date, participation in preparing the WK17049 has primarily involved members of Subcommittee C09.65, however, involvement of other ASTM members is both welcomed and encouraged.
Technical Information: Boyd Clark, RJ Lee Group, Monroeville, Pa.
ASTM Staff: W. Scott Orthey