PETROGRAPHY
Durability Engineers, in partnership with RJ Lee Group, performs petrographic examinations and laboratory analyses to investigate material failures, incompatibilities, and deterioration of cementitious materials, aggregates, mortars, grouts, and concretes. Petrographic analysis uses stereo, petrographic, and scanning electron microscopes to examine and evaluate the optical properties and microstructural characteristics of the materials.
WHAT IS CONCRETE PETROGRAPHY?
PE-TRO-GRAPHY (Noun) Defined in ACI 2018 CT-18 as "(1) the branch of petrology, dealing with description and systematic classification of rocks aside from their geologic relations, mainly by laboratory methods, largely chemical and microscopical...(2) laboratory study of concrete and mortar samples to determine various characteristics including, but not limited to, w/c, paste-aggregate bond, and air content."
APPLICATIONS OF PETROGRAPHY
Petrographic examination, in conjunction with hardened air-void analysis and scanning electron microscopy, can provide information concerning:
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Air content and distribution
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Estimated w/cm ratio
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Cracking
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Degree of Hydration
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Aggregate type, composition and soundness
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Secondary Deposits
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Binder type and paste content
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Depth of carbonation
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Presence and Condition of Reinforcement
MATERIAL EVALUATION
Petrographic analysis is regularly used to identify causes of distress and deterioration in materials, as well as predict future performance of the materials, and can aid in the evaluation of a number of issues, which include, but are not limited to:
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Surface Scaling
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Aggregate Popouts
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Low Strength Results
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Improper Finishing or Curing Techniques
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Cement-Aggregate Reactions
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Discoloration of Staining
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Chemical Attack
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Cause of Cracking Distress
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Fire and Heat-Related Damage