Derek X. Cong

Associate Principal


Derek Cong has significant practical and theoretical experience with concrete and concrete materials. In over twenty-five years of practice, he has conducted thousands of investigations involving concrete, aggregate, masonry, stone, and other building materials. These investigations have included problems such as alkali-aggregate reaction (AAR), alkali-silica reaction (ASR), low strength, retardation, cement-admixture interaction, efflorescence, delamination, and other surface defects, fire-damaged concrete, cracking, sulfate attack, and delayed ettringite formation (DEF). He is often consulted on concrete mix designs to avoid concrete material problems.

During his doctoral studies at the University of Illinois at Urbana-Champaign, Dr. Cong conducted extensive research on cement hydration, structure of calcium silicate hydrate (C-S-H), and ASR using solid state nuclear magnetic resonance (NMR) spectroscopy. As a post-doctoral research associate for Lawrence Livermore National Laboratory, Dr. Cong performed hydrothermal synthesis of various model compounds for C-S-H. Prior to joining WJE, Dr. Cong held positions with W. R. Grace and the Erlin Company. He also taught optical mineralogy and petrography at Central South University in China.



  • Seabrook Station - Seabrook, NH: On-site petrography and Damage Rating Index (DRI) determination for assessment of ASR-induced distress
  • Wolf Creek Generating Station - Burlington, KS: Petrographic examination of concrete for ACR-induced cracking
  • California Department of Transportation (Caltrans): Petrographic examination of concrete and aggregate samples for ASR Correlation Studies
  • Sixth Street Bridge - Los Angeles, CA: Petrographic examination of ASR-deteriorated concrete cores
  • I-5 Undercrossing - Santa Clarita, CA: Assessment of fire-damaged concrete
  • World Trade Center - New York, NY: Petrographic examination of concrete cores for general properties of concrete
  • Robert D. Moreton Building - Austin, TX: Petrographic and laboratory evaluation of concrete cores to assess the cause of cracking and predict the potential for DEF


Aggregate and Dimension Stone

  • LBJ Presidential Library, University of Texas at Austin: Laboratory evaluations of granite panels
  • LNG Tanks - Sabine Pass, LA/TX: Assessment of aggregate and concrete samples for various material properties from liquefied natural gas (LNG) tanks


Mortar Evaluation

  • Camp Mabry - Austin, TX: Historical mortar evaluation and mix proportions
  • Investigation of mortar mix proportions


Litigation Consulting

  • GB Biosciences Corporation et. al. vs. Occidental Chemical Corporation, et. al - Houston, TX: Testimony on private arbitration regarding CFB ash samples
  • Trinity Drywall Systems, LLC vs. TOKA General Contractors, Ltd., et. al. - Fort Worth, TX: Testimony regarding stucco problems
  • Maisel Brothers, Inc. vs. Holcim (US), Inc. et. al. - Severna Park, MD: Technical and litigation support on the cause of concrete masonry unit (CMU) block staining and pop-outs problems


Research and Testing

  • Investigation of cementitious materials content and w/cm in hardened concrete
  • ASR potential in concrete
  • Quantitative determination of crushed carbonate in hardened concrete
  • Petrographic techniques
Professional Affiliations

American Concrete Institute (ACI), Central Texas Chapter
ASTM International (ASTM)
International Cement Microscopy Association (ICMA)
Society of Concrete Petrographers (SCP), founding member and past president


Central South University
Bachelor of Science, Geology, 1982
Master of Science, Petrology, 1985

University of Illinois at Urbana-Champaign
Doctor of Philosophy, Geology/Materials Science, 1994