PetroThin | GERMANN

Thin sections are used extensively by petrographers to study the microstructure of concrete. As discussed in ASTM C856, “Standard Practice for Petrographic Examination of Hardened Concrete,” examination of thin sections of concrete and related materials is one of the most powerful methods for determining and characterizing the following features:

• The water-cement (w/c) ratio
• The cement type, degree of hydration, and dispersion of cement particles
• The type of pozzolan, degree of hydration, and cement-pozzolan ratio
• Mixture proportions
• Aggregate type, gradation, and quality
• Crack measurement and characterization
• Air-void structure
• Surface structure and finishing defects
• Alkali silica reaction (ASR)
• Alkali carbonate reaction (ACR)
• Delayed ettringite formation (DEF)
• Freezing and thawing damage
• Freezing of fresh concrete
• Bleeding characteristics
• Depth of carbonation
• Deleterious aggregates