Failure Analysis & Materials Characterization

- For a first class independent opinion -

Petrographic analysis is a very valuable and indispensable tool in the fields of quality control and failure analysis of young as well as old concrete. Performing petrographic analyses in a logical sequence and using qualified personnel makes this type of analysis fundamental in concrete characterization as well as in any other materials characterization analysis.  

Concrete Experts International offers petrographic services in the field of failure analysis of concrete and related materials as well as in materials characterization in general. CXI uses a combination of optical microscopy, scanning electron microscopy, and chemical analysis in their analysis. These types of analysis are fundamental in the understanding of natural as well as man made material and is well known in most natural sciences. Petrography is a term known from geology meaning, "the systematic characterization of rocks in hand specimen and thin section".

A well-performed analysis should elucidate the responsibility and causes of failure, as well as suggestions for repair.

Systematics during analysis guarantee that no important information has been lost or overlooked and that the obtained conclusions are well documented and reliable.

The staff of Concrete Experts International is highly qualified and has a worldwide reputation in failure analysis of concrete and materials characterization in general. The basis for providing our clients with a superior well documented failure analysis is the following suit of investigations:

  • Field examination of the structure
  • Petrographic analysis consisting of a macroscopic examination of cores and other types of samples and a microscopic examination of fluorescent impregnated thin sections prepared from concrete cores. 
  • Determination of w/c 
  • Evaluation of raw materials and production data and methods - if available.

Depending on the actual case the following types of analysis may be added to increase level of documentation:

  • Scanning electron microscopy (SEM) of fluorescent polished thin sections
  • XRD analysis of powdered material
  • Chemical analysis e.g. sulfate and chloride analysis
  • Absorption, air void analysis etc.

CXI uses yellow fluorescent microscopy during petrographic examination making determination of w/c easy and emphasize defects such such as micro-cracking and bleeding in concrete.

The staff of CXI has extensive experience in diagnosing all types of deterioration mechanisms occurring in concrete e.g. alkali silica reaction, delayed ettringite formation, external sulfate attack, acid attack and carbonation

CXI is highly skilled in the interpretation of the micro-structural appearance of materials which makes CXI able to evaluate whether a failure is caused by faulty mix design or poor workmanship during casting and curing.

Concrete wall along the Rideau Canal damaged from freeze/thaw.

Concrete core drilled from cracked dock wall.

Ettringite in voids as viewed in crossed polarized light with gypsum plate.

Porosity differences at surface of concrete viewed in fluorescent light mode.

Gypsum in cracks in concrete attacked by sulfate. Mg has replaced Ca in cement grains (dark gray phases). SEM Backscatter image.
|Top| |Home|
Concrete Experts International can be reached at:
Gøngehusvej 242, DK-2950 Vedbæk, Denmark
Tel: +45 2835 0660
Copyright © Concrete Experts International | Last updated: 04/09/09