ASTM C295 / C295M: Standard Guide for Petrographic Examination of Aggregates for Concrete.
ASTM C856: Standard Practice for Petrographic Examination of Hardened Concrete.
Uses of Petrographic Analysis
Petrographic analysis is the starting point in the evaluation of concrete. They include:
- Finding the causes of inferior quality, distress, or deterioration of concrete.
- Determination whether the concrete in a construction was or was not as specified.
- Provide description of the cementitious matrix, including qualitative determination of the kind of hydraulic binder used, degree of hydration, degree of carbonation if present, presence of a mineral admixture, the nature of the hydration products, adequacy of curing, and unusually high water – cement ratio of the paste.
- Identify whether the concrete has been subjected to and affected by sulfate attack, or other chemical attack, or early freezing, or to other harmful effects of freezing and thawing.
- Determination whether concrete subjected to fire is essentially undamaged or moderately or seriously damaged.
- Determination of the factors that caused a given concrete to serve satisfactorily in the environment in which it is taken from
Sulfate attacked concrete
Evaluation of granite sample