ASTM C1723 − 10 Standard Guide for Examination of Hardened Concrete Using Scanning Electron Microscopy

ASTM C1723 − 10 Standard Guide for Examination of Hardened Concrete Using Scanning Electron Microscopy

Scope
1.1 This guide provides information for the examination of hardened concrete using scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDX).

Since the 1960s, SEM has been used for the examination of concrete and has proved to be an insightful tool for the microstructural analysis of concrete and its components.

There are no standardized procedures for the SEM analysis of concrete.

SEM supplements techniques of light microscopy, which are described in Practice C856, and, when applicable, techniques described in Practice C856 should be consulted for SEM analysis.

For further study, see the bibliography at the end of this guide.

ASTM C1723 − 10 Standard Guide for Examination of Hardened Concrete Using Scanning Electron Microscopy

Terminology

3.1 Definitions of Terms Specific to This Standard:

3.1.1 BSE, n—backscatter electrons; these are high-energy electrons emitted back from the specimen surface.

Elements of higher atomic number will have stronger emissions and appear brighter.

3.1.2 brightness, n—the amount of energy used to produce an X-ray.

3.1.3 charging, n—the buildup of electrons on the specimen at the point where the beam impacts the sample.

Charging can alter the normal contrast of the image (usually becomes brighter) and may deflect the beam.