ASTM C856

Full Name

ASTM C856 – Standard Practice for Petrographic Examination of Hardened Concrete

Scope

ASTM C856 is a standard practice that outlines procedures for the petrographic examination of hardened concrete samples. This examination involves the use of microscopes to analyze the composition, microstructure, and properties of concrete at a microscopic level.

Key aspects covered by ASTM C856 include:

  • Purpose: the primary purpose is to provide guidance on conducting petrographic examinations of hardened concrete samples for various purposes, such as:
    • Assessing the quality and durability of concrete.
    • Identifying the causes of any problems or deterioration.
    • Evaluating the effectiveness of different concrete mixtures and curing methods.
    • Optimizing the design of new concrete structures.
  • Sample types: the standard applies to samples taken from concrete constructions, concrete products, or concrete specimens that have been exposed to various environments or tests.
  • Examination techniques: it describes different microscopic techniques used for examining concrete, including:
    • Optical microscopy
    • Scanning electron microscopy
    • X-ray diffraction
    • Chemical analysis
  • Interpretation: it provides guidelines for interpreting the results of the petrographic examination, including identifying and quantifying the various components of concrete (aggregates, cement paste, air voids) and assessing their condition.
  • Reporting: it outlines the information that should be included in a petrographic report, including a description of the samples, examination techniques, findings, and conclusions.

By following ASTM C856, engineers and researchers can gain valuable insights into the properties and performance of concrete, leading to improved design, construction, and maintenance of concrete structures.

ASTM C856 Accredited Laboratory

Applied Testing & Geosciences, LLC is accredited for performing tests using the ASTM C856 standard.

Contact us for more information.

Resources

Keywords

petrographic examination; hardened concrete; microscopy; aggregate; cement paste; air voids; cracking; alkali-silica reaction; sample preparation; thin section