A5040385641- Concrete and Cement Materials Research
- Concrete Properties and Behavior
- Magnesium Oxide Properties and Applications
- Innovative concrete reinforcement materials
- Building materials and conservation
- Advanced ceramic materials synthesis
- Drilling and Well Engineering
- Laser Material Processing Techniques
- Microwave-Assisted Synthesis and Applications
- CO2 Sequestration and Geologic Interactions
- Innovations in Concrete and Construction Materials
- Calcium Carbonate Crystallization and Inhibition
- Hydrocarbon exploration and reservoir analysis
- Clay minerals and soil interactions
- Risk and Safety Analysis
- Soil and Unsaturated Flow
- Reservoir Engineering and Simulation Methods
- Non-Destructive Testing Techniques
- Infrastructure Maintenance and Monitoring
- Glass properties and applications
- Hygrothermal properties of building materials
- Occupational Health and Safety Research
- Mine drainage and remediation techniques
- Grouting, Rheology, and Soil Mechanics
- MXene and MAX Phase Materials
ExxonMobil (United States)
2024
University of Colorado Boulder
2023
Pennsylvania State University
2014-2022
Freeport-McMoRan (United States)
2014-2022
Applied Research Laboratory at Penn State
2022
GCP Applied Technologies (United States)
2021
Applied Technologies (United States)
2021
Schlumberger (United States)
2010-2018
Massachusetts Institute of Technology
2015
Schlumberger (Norway)
2014
The fundamental chemical hydration process of portland cement and its main mineral component, tricalcium silicate, was studied by investigating the effects various additives. A relatively small amount (1−4 wt %) well-dispersed calcium silicate hydrate (C−S−H), a pure form product, significantly increases both early rate total during nucleation growth period (the first ∼24 h), as measured calorimetry. This is attributed to seeding effect whereby C−S−H additive provides new sites within pore...
The hydration kinetics of tricalcium silicate (C 3 S), the main constituent portland cement, were analyzed with a mathematical “boundary nucleation” model in which nucleation product occurs only on internal boundaries corresponding to C S particle surfaces. This more closely approximates process than does widely used Avrami and growth model. In particular, boundary accounts for important effect powder surface area kinetics. Both models applied isothermal calorimetry data from hydrating...
Cement-based materials have complex multi-component, multiscale structures that first form through chemical reaction and then continue to change with time. As most classes of materials, the porosity cement paste strongly influences its properties, including strength, shrinkage, creep, permeability diffusion. Pores in range size from nanometers millimeters, numerous investigations models been reported literature. This paper reviews some key concepts related our understanding pore system...
The importance of concrete and cement to civil infrastructure cannot be overstated, yet there are still surprising gaps in our knowledge these systems, which unexpectedly complex. One basic example is that paste shrinks when water removed from its multiscale pore network, swells added, but the mechanism unclear. In a complete reassessment this phenomenon, authors differentiate physical behavior layered nanostructures hydrates larger gel capillary pores, linking microstructure macroscopic...
Microstructure development and the kinetics of hydration pure tricalcium silicate (C3S) CaCl2-accelerated C3S pastes were investigated by performing isothermal calorimetry in situ small-angle neutron scattering (SANS) measurements on parallel specimens during first few days hydration, as well 28-day old hydrated under same curing conditions (water/cement ratio = 0.5, 20 °C). Calorimetry experiments also performed over a range temperatures from 10 to 40 °C. The data analyzed applying...
Relationships between composition, mass density, and atomic packing density for CaO−SiO2−H2O (C−S−H), the main hydration product of cement, its mineral analogues tobermorite jennite, are examined. A graphical approach, similar to a phase diagram, is used display variation in as function water content. In order provide insight into differences these phases, hypothetical transitions performed by adding stoichiometrically correct amount CaO H2O convert one another, then molar volumes before...
The effects of drying to various relative humidity (RH) levels on the internal structure hydrated cement paste were investigated using small‐angle neutron scattering (SANS). Specimens young and mature portland analyzed in initial saturated state, dried then again after resaturation, allowing reversible irreversible be separated. While observed changes are mainly physical nature, ability microstructure resist permanent structural rearrangement increased over time as hydration aging reactions...
The kinetics of hydration magnesium oxide (MgO) powder to form hydroxide (Mg(OH) 2 ) were measured using isothermal calorimetry at different temperatures, and the morphology powders before after examined. light‐burned MgO exhibit a rate peak similar that portland cement hydration, whereas hard‐burned are comparatively slower same temperature, continuously declining first several minutes reaction. both can be fit boundary nucleation growth model has previously been applied tricalcium...