Opportunity at National Institute of Standards and Technology (NIST)
Microstructural Modeling of Cement-Based Materials
Engineering Laboratory, Materials and Structural Systems Division
Please note: This Agency only participates in the February and August reviews.
|Bentz, Dale Patrick
|Bullard, Jeffrey W.
The microstructure of cement-based materials, such as concrete, is complex over a wide range of length scales from nanometers to centimeters. Microstructure and its relationships to physical properties must be quantitatively understood if these widely used construction materials are to be improved and optimized. Our goal is to develop a suite of computer models to track the phase evolution and microstructure development at three scales of interest: (1) the nanostructure of the calcium silicate hydrate gel hydration product, (2) the microstructure of hydrating cement paste, and (3) the macrostructure of concrete. Computational techniques consist of cellular automata, geochemical models, hard core/soft shell models adopted from the statistical physics literature, and finite difference/finite element methods. Properties of interest include heat release, percolation of phases, diffusivity, strength, and drying and autogenous shrinkage. Model predictions are compared to experimental data from the available literature and generated from in-house studies. Experimental facilities include iosthermal calorimeters, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy with X-ray detection, atomic force microscopy, X-ray diffraction, ICP analysis, and an X-ray CT. Computers include a 600 processor Linux cluster and specialized systems for three-dimensional visualization and computer graphics.
Cement hydration; Computer simulation; Microstructure; Modeling; Transport properties;
Open to U.S. citizens
Open to Postdoctoral applicants