Postdoctoral Fellow (PREP0004126) Full-time

Postdoctoral Fellow

This position is part of the National Institute of Standards (NIST) Professional Research Experience (PREP) program. NIST recognizes that its research staff may wish to collaborate with researchers at academic institutions on specific projects of mutual interest, thus requires that such institutions must be the recipient of a PREP award. The PREP program requires staff from a wide range of backgrounds to work on scientific research in many areas. Employees in this position will perform technical work that underpins the scientific research of the collaboration.

Research Title: Advanced Metrology for Novel Infrastructure Materials

The work will entail: The Infrastructure Materials Group is seeking a highly motivated Research Associate to be a part of the Forward Looking Building Standards initiative within NIST. As the construction industry pivots toward low-carbon binders–such as Type IL (Portland-Limestone) and Calcium Sulfoaluminate (CSA) cements–traditional prescriptive building codes are becoming obsolete. We are looking for a researcher who can bridge the gap between fundamental geochemistry and applied standardization. You will develop the measurement science required to predict the long-term durability of these novel materials, ensuring the nation's infrastructure remains resilient for decades to come.

The National Institute of Standards and Technology (NIST) promotes U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life. Located in Gaithersburg, Maryland, NIST offers a collaborative, interdisciplinary culture where you will work alongside some of the world's leading scientists and engineers to solve critical national challenges.

The Infrastructure Materials Group (IMG) serves as the nation's premier resource for developing the science-based tools–measurements, data, models, protocols, and reference standards–needed to evaluate the performance of conventional and innovative building materials. As part of the Engineering Laboratory, the IMG focuses on predicting the service life of infrastructure components when exposed to real-world and accelerated weathering environments.

We are specifically targeting a researcher with a rigorous background in pore solution chemistry and transport properties. The ideal candidate does not just run standard tests; they understand the thermodynamic mechanisms driving durability. You should be comfortable moving between the wet lab (extracting and analyzing pore solutions) and the computer (modeling phase assemblages and quantifying uncertainty).

Experience determining the Formation Factor of concrete, using XRF for pore solution analysis, or modeling hydration kinetics using GEMS/PHREEQC, are critical skills needed for this position.

Key responsibilities will include but are not limited to:

• Advance Measurement Science: Develop and validate novel test methods for characterizing alternative cementitious materials, with a specific focus on linking microstructural development to macro-scale transport properties.
• Pore Solution Characterization: Lead efforts to standardize X-ray Fluorescence (XRF) techniques for the elemental analysis of concrete pore solutions, establishing protocols for characterizing accuracy and repeatability.
• Durability Modeling: Apply thermodynamic modeling to predict phase changes (e.g., carbonation, chloride binding) in Type IL and CSA cements under varying climate scenarios.
• Uncertainty Quantification: Use advanced statistical frameworks (Bayesian inference, Monte Carlo simulations) to analyze experimental data, and to quantify the uncertainty in service-life predictions for code development.
• Code & Standard Development: Translate research findings into actionable proposals for ASTM and ACI committees, directly influencing the next generation of building codes.

Qualifications

Required:

• Education: Successful candidates should have completed a Ph.D. in any one of Chemistry, Physics, Mechanical Engineering, Chemical Engineering, Civil Engineering, or Materials Science at the time of the position start date, with a focus on chemistry and material science of cementitious materials.
• Cementitious Materials Science Background: Demonstrated experience conducting quantitative laboratory measurements on cementitious materials: X-ray diffraction (XRD), thermogravimetric analysis (TGA), isothermal calorimetry, scanning electron microscopy (SEM).
• Modeling and Computational: Demonstrated experience using computation tools such as COMSOL, Python/Matlab/R.
• Uncertainty Quantification: Demonstrated ability to apply statistical methods to quantify the uncertainty of experimental measurements, beyond linear least-squares regression.

Preferred:

• Specialized Metrology: Peer-reviewed publication utilizing one of the following techniques
• Quantitative Phase Analysis (QPA) using X-ray Diffraction, including the use of the Internal Standard Method to quantify amorphous contents in hydrated cementitious systems.
• Composition Analysis using X-ray fluorescence to quantify the elemental composition of solutions.
• Transport & Durability: Demonstrated understanding of the Nernst-Einstein relationship, electrical resistivity measurements, and the determination of the Formation Factor in cementitious systems.
• Thermodynamic Modeling: Proficiency with geochemical modeling software (e.g., GEMS, PHREEQC, or Oli) to simulate cement hydration and phase stability in low-carbon binders.
• Alternative Binder Expertise: Demonstrated research experience with Calcium Sulfoaluminate (CSA) cements, Type IL cements, or alkali-activated materials.