Petrography
Petrographic Examination of Hardened Concrete
ASTM C856
Petrographic Examination Identifies Quality Issues That Contribute to the Deterioration, Damage and Structural Failure of Concrete
The standard practice for ASTM C856 uses visual and microscopic analysis of hardened concrete samples to determine valuable insight into internal microstructure, material composition, origin, performance and overall condition.
Samples, typically prepared from core extractions or test cylinders, are cut, ground, and polished. These prepared surfaces are then analyzed under a microscope, using magnifications from 10x to 60x for lapped sections and up to 400x for thin sections.
Assess a Range of Important Concrete Properties
Examinations following ASTM C856 guidelines can identify and confirm:
- Water to Cement Ratio
- Air Content
- Chemical Attack
- Alkali Silica Reactions (ASR)
- Freeze Thaw Damage
- Paste Carbonation
- Low Strength Concrete
- Coating Failure or Delamination
- Moisture Vapor Issue
- Improper Curing
- Consolidation
- Porosity of Paste
- Corrosion of Reinforcing Steel
- Fire Damage
- Cracking Investigation
- Sulfate Attack
- Improper Finishing
- Seismic Damage
- Supplemental Cementitious Material (Fly Ash, Slag, etc.)
- Aggregate Mineralogy
- Aggregate Segregation
- Topping Verification
- Water Content
Get Answers to Critical Questions and Make Informed Decisions
From cracking and scaling to gel expansion and curing failures, petrography provides the answers needed to identify and solve concrete quality and durability problems.
Common questions our petrographers help answer include:
- Why are my compressive strength values less than the design?
- How do I know the provided concrete matches the mix design?
- Was too much air entrainment added to the concrete?
- Why did the surface of the concrete flake off?
- What is the existing condition of the concrete in my 40 year old building?
- Why is my concrete a completely different shade of gray in some areas?
- Is the existing surface of my concrete slab capable of accepting a coating?
- Why are there so many cracks in my slab?
- Is it time to remove and replace the existing concrete slab?
Our accredited petrography laboratory provides a comprehensive range of testing services, learn more about concrete testing or speak with a petrographer today.
