Petrographic Laboratory Analysis (ASTM C856, C294/C295, C457, & More)

One of the most effective methods used to evaluate building materials quality, diagnose causes of deterioration, and determine extent of damage is petrographic examination.

It is applicable to aggregates, concrete, mortar, grout, plaster, stucco, terrazzo, building stone, and similar materials. Petrographic methods combine unaided visual inspection and examination using stereo, petrographic & metallographic microscopes, and scanning electron microscopes. CTLGroup’s expert interpretation of findings helps develop practical solutions to our clients’ problems.

Petrographic examination is often supplemented with chemical analysis, and X-ray diffraction analysis. Physical tests develop data on compressive strength, volume change, air content of hardened concrete, freeze-thaw durability, and rapid chloride permeability.

Petrographic examination of concrete can provide descriptive information that includes:

• Degree of cement hydration
• Estimation of water-cement ratio
• Extent of paste carbonation
• Presence and amount of fly ash
• Extent of corrosion of reinforcing steel
• Evidence of alkali-aggregate reaction, sulfate attack or other chemical attack
• Presence of potentially reactive aggregates
• Evidence of improper finishing
• Estimation of air content
• Evidence of early freezing
• Causes of cracking

CTLGroup regularly performs a variety of laboratory analyses for our clients. Below is a list of our most frequent tests related to Petrography. Please keep in mind that we cater our testing to each client’s specific needs. If a test you need is not on this list, please contact us to discuss in depth.