Postdoctoral researcher
Damage to concrete structures in residential and commercial construction in central Connecticut has
been attributed to the iron sulfide mineral pyrrhotite. Iron sulfides in concrete aggregate are not
desirable as their relative instability results in decomposition with associated staining, expansion, and
pop-outs near concrete surfaces or, in severe cases, cracking of the structure. There are no standardized
test methods to assess pyrrhotite occurrence and abundance in aggregate or in concrete due to its low
concentrations while still having a significant impact. Developing a standard test method, including a set
of calibration reference standards will provide a means for accurate, consistent analysis of pyrrhotite in
concrete. An improved understanding, based on modeling and experimental data, of the
pyrrhotite/aggregate/concrete reaction types, reaction rates, and reaction product impact on concrete
expansion, is needed so that the most deleterious reactions can be efficiently reduced or eliminated.
In this opportunity, the PREP researcher will develop models to better understand the
microstructural characteristics relevant to the internal sulfate expansion phenomena, including its
volume expansion.
Understanding Concrete Foundation Deterioration by Modeling the Impact of Pyrrhotite
- Ph.D. in Chemistry/ Physics/ Mechanical Engineering/ Chemical Engineering/ Civil
Engineering - Minimum of one year of experience of modeling pyrrhotite reactions and resulting
damage in concrete with proof of peer-reviewed publications - Knowledge of concrete durability, i.e., chemo-mechanical modeling, diffusion,
thermodynamic modeling. - Extensive knowledge of FEM, and programming skills in Fortran and C++.
- Strong oral and written communication skills
- Currently living in the United States
- U.S. citizenship is preferred
Key responsibilities will include but are not limited to:
- chemo-mechanical modeling to simulate the expansion and the damage in concrete,
- thermodynamic modeling to evaluate the reactions in cement phases due to pyrrhotite
oxidation, - crack progression modeling using Finite Element Model (FEM) to simulate cracking behavior due
to internal phases expansion, - moisture transport modeling that considers the distressed concrete due to pyrrhotite,
- surface coating simulation modeling,
- interfacing with NIST experimentalists to support and validate modeling work,
- analyzing modeling results and drafting manuscripts.