Petrographic Analysis

Looking for an independent, reputable third-party to evaluate the condition of existing concrete or to determine why concrete has cracked, delaminated, spalled or failed in any other manner? M+P Labs performs petrographic analysis to evaluate the integrity of concrete, determine the root causes for defects and provide recommendations for remediation.

Our evaluations can answer the following types of questions:

  • Did the materials used match the concrete mix design?
  • What was the water/cement ratio?
  • What is the entrapped and entrained air content?
  • Was the concrete placed properly?
  • Was it finished properly?
  • Did it cure properly?
  • Were there any compatibility issues between the materials or with the environment?
  • Did chlorides or de-icing agents have a deleterious effect?
  • Should we repair or replace the concrete?

Examples of investigations we have conducted include evaluation of bridge decks and columns, roads, parking lots and structures, manufacturing floors, concrete overlays, concrete/terrazzo floors, and sidewalks.

Test methods we perform include:

Unit weight and absorption (ASTM C642) Measurements obtained are compared to the mix design specifications.

Water-soluble chloride content (ASTM C1152) Chlorides promote the corrosion of steel reinforcement and may induce concrete to crack or spall.

Air void analysis (ASTM C457) Performed on polished core cross-sections using state-of-the-art calibrated image analysis software. This analysis provides detailed information about the relative composition and distribution of coarse and fine aggregate, cement paste, entrained and entrapped air.

Petrographic analysis (ASTM C856) A microstructural examination by optical and scanning electron microscopy (SEM) of the paste and aggregate on a prepared sample of concrete to look for features such as degree of cement hydration, microcracking, reaction products, breakdown of aggregate and evidence of poor freeze-thaw performance. A mineralogical assessment of the aggregate is also performed to determine if appropriate aggregate was used and if it caused any deleterious reactions.

FTIR analysis Utilized to identify contaminants and verify the composition of binders, epoxies, coatings, and other organic materials.

Detailed reports provided by M+P Labs include an assessment of the concrete based on the information provided by the client, laboratory testing results, high-resolution images illustrating features of interest, and recommendations for remediation. If you are interested in receiving a sample concrete investigation report prepared by M+P Labs, please request a copy through our Inquiry button.

For clients in the northeast U.S., we also offer the following services:

  • On-site inspection
  • Core location selection
  • Coring services
  • Delamination surveys
  • Covermeter surveys
  • Half-cell potential surveys
  • Expert witness services