Course: Petrographic analysis of hardened concrete

Concrete petrography (micro structure)

  • Identification of phases, magnifications
  • Cement types
  • Degree of hydration
  • Puzzolans
  • Capillarity, equivalent W/C ratio, paste density
  • Microstructure development
  • Dispersion levels, homogeneity, connectivity
  • Cracks
  • Bonding and de-bonding phenomena
  • Quantitative analysis, image analysis systems
  • Carbonation, diagenesis, leaching, precipitation
  • AAR, Sulphate attack, frost damage, DEF, fire attack
  • Fibres

Concrete petrography (macro structure)

  •  Coarse aggregate parameters
  •  Distribution of constituent
  • Compaction levels and flow characteristics
  • Cracks
  • AAR, frost damage, fire

Sample preparation

  • Selection of samples and sub-samples
  • Fracture surfaces
  • Vacuum impregnations
  • Thin section production, preparation defects
  • Polished samples, contrast impregnation

Concrete technology

  • Compositions of concrete
  • The impact of composition on shrinkage and heat of hydration
  • Rheology vs. packing
  • The influence of powder designs
  • Bonding influence on effective W/C ratio
  • Compaction techniques in relation to micro structure
  • Bleeding vs. 'dry porosities'
  • Repairs and repair strategies

Equipment and set up

  • Cutting, grinding and polishing machines
  • Cooling media
  • Polarization microscope, SEM, EDX, ESEM
  • Filters and light sources for light microscopes and photo set-up

Crack in granite extending into cement paste with plug of ASR-gel

Clumps of silica fume

Reaction rings in a slag grain

Portlandite around fly ash particle