Petrographic Analysis of Hardened Concrete

Pelcon has a long experience in preparing and analyzing fluorescence impregnated thin and plane sections. Moreover we conduct analysis on split fully fluorescence impregnated cores, various aggregates, mortar and sand.

Based on the analysis of thin sections a long series of parameters and properties can be described, among those:

  • w/c-ratio and homogeneity of cement paste
    A 20µm thick fluorescence impregnated thin section in uv-light. The dimensions are 45mm x 30mm x 0.020mm.
  • Cement type and content
  • Paste hydratisation and content of microcracks
  • Sand quality and potential alkali reactivity
  • Puzzolan type, quantity and quality
  • Bleeding and paste stability while the concrete was still plastic
  • Bonding quality and ITZ for paste-sand and paste-stone
  • Degree of carbonation
  • Age of concrete
  • Crack and defect investigation

The analysis of plane sections can supplement or clarify another set of parameters and properties:

  • Internal stability
  • Degree of compaction
  • Bonding quality of paste-stone and paste-reinforcement
  • Stone content and distribution
  • Formation of layers
  • Evaluation of casting joints
  • Crack and defect investigation
Elongated portlandite crystals in an air void
The yellow is epoxy and the white is the intact glass phase of the volcanic ash in which a crushed crystal is located
Fossil in concrete under UV-light, where the concrete is impregnated in fluorescent epoxy
Cell division in wood under high magnification

Example of a fluorescence impregnated plane section (Size: 100x200mm) seen in normal light and UV light:


Plane and thin sections are prepared in accordance with Danish Standards:

  •  DS 423.39 Production of fluorescence impregnated plane sections
  •  DS 423.40 Production of fluorescence impregnated thin sections (Accredited)

Analyses are conducted in accordance with:

  • DS 423.36 Determination of the amount of silica fume in clumps (Accredited)
  • DS 423.41 Internal stability (Accredited)
  • DS 423.42 Concrete composition (Accredited)
  • DS 423.43 Paste homogeneity (Accredited)
  • DS 423.44 Paste cracks and bond cracks (Accredited)
  • DS 423.45 Degree of compaction (Accredited)
  • TI-B 5 Structure analysis in connection with QC
  • ASTM C457/C457M Microscopical determination of Parameters of the Air-Void System in Hardened Concrete (Accredited)
  • ASTM C856/C856M Standard Practice for Petrographic Examination of Hardened Concrete (Accredited)