Associate Research Scientist (PREP0005163)

Johns Hopkins University; Baltimore (MD); On-site; USD 85,000 - 120,000; Full time

Job summary

Johns Hopkins University seeks a Postdoctoral Research Associate to join the PREP program at NIST, Gaithersburg, MD. The role focuses on accelerated corrosion studies in reinforced concrete and developing metrology standards for cementitious materials, combining wet-lab measurements with computational modeling.

The ideal candidate will design and execute electrochemical tests, analyze pore solutions, and help translate results into durable service-life predictions and building-code inputs.

Qualifications

• Ph.D. in a relevant field with focus on chemistry and material science of cementitious materials or corrosion.
• Experience conducting quantitative laboratory measurements on cementitious materials (XRD, TGA, calorimetry, SEM).
• Experience with corrosion mechanisms of metallic systems and advanced electrochemical testing.

Responsibilities

• Advance Measurement Science: develop/validate novel test methods linking microstructure to transport properties.
• Pore Solution Characterization: standardize XRF for concrete pore solutions and establish protocols.
• Durability Modeling: apply thermodynamic modeling to predict phase changes in cements under climate scenarios.
• Corrosion Science: perform EIS, polarization, OCP, LPR to quantify corrosion metrics; develop PDM parameters.
• Microstructural Characterization: use SEM-EDS to study steel-concrete interface.
• Model Integration: translate bench data into inputs for numerical/structural models.
• Uncertainty Quantification: apply Bayesian methods and Monte Carlo simulations to predictions.
• Code & Standard Development: contribute to ASTM/ACI committee proposals.

Skills

Corrosion science

Cementitious materials science

Electrochemistry

Education

Ph.D. in Chemistry/Physics/Mechanical/Chemical/Civil/Materials Science

Tools

XRF

GEMS/PHREEQC

XRD

TGA

SEM-EDS

OCP

EIS

Job description

PREP Research Associate

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: Accelerated Corrosion Studies of Reinforced Concrete

The Infrastructure Materials Group (IMG) is seeking a highly motivated Research Associate to be a part of the Next-Generation Building Standards initiative within NIST.

Degradation of reinforced concrete due to embedded steel corrosion remains a monumental challenge, with direct and indirect costs accounting for approximately 6% of the U.S. Gross Domestic Product. Current building codes, testing standards, and common-practice heuristics, such as diffusion coefficient, depth of cover, and chloride per unit mass of cement, are inadequate for assessing the complex environmental factors and novel binder chemistries that most strongly affect structural service life. To address this, the IMG "Assessing Steel Corrosion Risk in Innovative Cement Concretes" project aims to integrate advanced electrochemical characterization with species-transport modeling. We are seeking a highly motivated Postdoctoral Researcher with academic training and experience in corrosion science to develop new metrology standards specific to reinforced concrete structures, which are often in unsaturated conditions. The selected candidate will focus on measuring the precise rates of corrosion initiation and progression, ultimately providing the foundational data needed to build high-fidelity service-life and fragility models for reinforced concrete structures.

The National Institute of Standards and Technology (NIST) promotes U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology to 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.

IMG at NIST serves as an important resource for developing science-based tools and measurement standards to enhance the resilience and sustainability of the nation's physical infrastructure. As part of the Engineering Laboratory, the IMG focuses on predicting the service life of infrastructure components under real-world and accelerated weathering conditions.

We are specifically targeting a researcher with a rigorous background in developing accelerated corrosion studies to inform long-term modeling and prediction of degradation. The ideal candidate does not just run standard tests; they understand the thermodynamic mechanisms that drive durability and those that drive corrosion initiation and propagation. You should be comfortable moving between the wet lab (extracting and analyzing pore solutions) and the computer (modeling phase assemblages and quantifying uncertainty).

Experience with cement pore solution chemistry and concrete transport properties, such as determining the Formation Factor using XRF for pore solution analysis or modeling hydration kinetics using GEMS/PHREEQC, is a critical skill needed for this position. Experience designing and conducting advanced electrochemical assessments of reinforcement steel to measure corrosion initiation and progression rates under varied solution properties and environmental conditions are required.

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. Corrosion Science

Corrosion Science

• Advanced Data Collection: Utilize Electrochemical Impedance Spectroscopy (EIS), potentiodynamic polarization, open‑circuit potential (OCP), and linear polarization resistance (LPR) to accurately quantify corrosion current density, corrosion potential, and charge transfer resistance. Also, develop measurement plans to obtain Point Defect Model (PDM) parameters for modeling rebar passivation and passive film breakdown.
• Microstructural Characterization: Perform high‑resolution materials characterization utilizing Scanning Electron Microscopy‑Energy Dispersive X‑Ray Spectroscopy (SEM‑EDS) to study the steel‑concrete interface and understand the morphology of localized degradation.
• Model Integration: Translate fundamental bench‑top corrosion data and transport property measurements into accurate inputs for numerical and structural models, connecting atomic‑level physicochemical mechanisms to building‑scale performance.
• 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.

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 or corrosion.
• 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).
  • 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.
• Corrosion Science Background: Demonstrated expertise in investigating corrosion mechanisms of metallic systems under a range of environmental and solution conditions.
  • Strong experience designing and executing laboratory experiments to study corrosion processes, including controlled electrochemical testing and environmental exposure studies.
  • Hands‑on laboratory experience with Electrochemical Impedance Spectroscopy (EIS) and Mott‑Schottky Analysis.
  • Experience with atmospheric corrosion and field exposure studies in marine environments, including sample design, deployment, and post‑exposure analysis.
  • Familiarity with accelerated corrosion testing methodologies and relevant ASTM and AMPP standards, particularly those related to corrosion rate measurements and chloride‑induced corrosion in reinforced concrete systems.
• A strong record of scientific productivity, evidenced by publications in peer‑reviewed journals.

Preferred

• 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.
• Proficiency in surface/sample preparation of metals for metallographic analysis and advanced microstructural characterization techniques, specifically Scanning Electron Microscopy‑Energy Dispersive X‑Ray Spectroscopy (SEM/EDS), Raman spectroscopy, X‑Ray Photoelectron Spectroscopy (XPS), optical profilometry, optical microscopy, and ion chromatography.

U.S. Citizen is Preferred

Salary Range

The referenced salary range represents the minimum and maximum salaries for this position and is based on Johns Hopkins University's good faith belief at the time of posting. Not all candidates will be eligible for the upper end of the salary range. The actual compensation offered to the selected candidate may vary and will ultimately depend on multiple factors, which may include the successful candidate's geographic location, skills, work experience, internal equity, market conditions, education/training and other factors, as reasonably determined by the University.

Total Rewards

Johns Hopkins offers a total rewards package that supports our employees' health, life, career and retirement. More information can be found here: https://hr.jhu.edu/benefits-worklife/.

Equal Opportunity Employer

The Johns Hopkins University is committed to equal opportunity for its faculty, staff, and students. To that end, the university does not discriminate on the basis of sex, gender, marital status, pregnancy, race, color, ethnicity, national origin, age, disability, religion, sexual orientation, gender identity or expression, veteran status or other legally protected characteristics. The university is committed to providing qualified individuals access to all academic and employment programs, benefits and activities on the basis of demonstrated ability, performance and merit without regard to personal factors or demographic characteristics that are irrelevant to the program involved.

Pre-Employment Information

If you are interested in applying for employment with Johns Hopkins University and require special assistance or accommodation during any part of the pre‑employment process, please contact the HR Business Services Office at [e-mail]. For TTY users, call via Maryland Relay or dial 711. For more information about workplace accommodations at Johns Hopkins University for disabilities, medical conditions (including medical conditions related to pregnancy or childbirth), accessibility, or religious reasons, please visit accessibility.jhu.edu.

Background Checks

After receiving a conditional offer, the successful candidate(s) for this position will be subject to a pre‑employment background check including education verification. When deciding whether a candidate's conviction history is job‑disqualifying, the University considers the nature and gravity of the offense, the time that has passed since the conviction, and the nature of the job being sought.

EEO is the Law

https://www.eeoc.gov/employees-job-applicants

Vaccine Requirements

Johns Hopkins University strongly encourages, but no longer requires, at least one dose of the COVID‑19 vaccine. This change does not apply to the School of Medicine (SOM). SOM hires must be fully vaccinated with an FDA COVID‑19 vaccination and provide proof of vaccination status. We still require all faculty, staff, and students to receive the seasonal flu vaccine.

Exceptions to the seasonal flu vaccine or COVID‑19 vaccine (for SOM) requirement(s) may be provided to individuals with sincerely held religious beliefs or medical conditions that preclude them from receiving the vaccine. Requests for an exception must be submitted to the JHU vaccination registry. For additional information, applicants for SOM positions should visit https://www.hopkinsmedicine.org/coronavirus/covid-vaccine/ and all other JHU applicants should visit https://covidinfo.jhu.edu/health-safety/covid-vaccination-information/.

The following additional vaccine requirements may apply, depending upon your campus. Please contact the hiring department for more information.

The pre‑employment physical for positions in clinical areas, laboratories, working with research subjects, or involving community contact requires documentation of immune status against Rubella (German measles), Rubeola (Measles), Mumps, Varicella (chickenpox), Hepatitis B and documentation of having received the Tdap (Tetanus, diphtheria, pertussis) vaccination. This may include documentation of having two (2) MMR vaccines; two (2) Varicella vaccines; or antibody status to these diseases from laboratory testing. Blood tests for immunities to these diseases are ordinarily included in the pre‑employment physical exam except for those candidates who provide results of blood tests or immunization documentation from their own health care providers. Any vaccinations required for these diseases will be given at no cost in our Occupational Health office.