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Christopher C. White, Kar T. Tan, Donald L. Hunston, Walter E. Byrd
Effective fire protection of steel can be fully realized when spray-applied fire resistive materials (SFRMs) are bonded sufficiently to structural steel during the event of fire. The adhesion mechanisms and characterization at elevated temperatures
Christopher C. White, Kar T. Tan, Donald L. Hunston, Kristen L. Steffens, Deborah S. Jacobs, Bulent Akgun, Vogt D. Bryan
Moisture attack on adhesive joints is a long-standing scientific and engineering problem. A particularly interesting observation is that when the moisture level in certain systems exceeds a critical concentration, the bonded joint shows a dramatic loss of
Christopher C. White, Kar T. Tan, Donald L. Hunston, Adam L. Pintar, James J. Filliben
An empirically-based model has been created to predict the change in modulus for a sealant exposed to outdoor weathering. The underlying high precision data supporting this model was obtained using the NIST SPHERE (Simulated Photo degradation by High
Construction aggregate particles, fine or coarse, can be mathematically characterized using spherical harmonic series and used to simulate random parking of irregular aggregates to form a virtual mortar or concrete using the Anm model. Any other similar
Yaghoob Farnam, M R. Geiker, Dale P. Bentz, Jason Weiss
Different constituents of concrete can have cracking behavior that varies in terms of the acoustic waveform that is generated. Understanding the waveform may provide insight into the source and behavior of a crack that occurs in a cementitious composite
William Ha, Dale P. Bentz, Wyatt Kahler, Laurence Walsh
Introduction: The setting times of commercial mineral trioxide aggregate (MTA) and Portland cements vary. It was hypothesized that much of this variation was due to differences in particle size distribution. Methods: Two gram samples from 11 MTA-type
Chiara F. Ferraris, Nicos Martys, Myoungsung Choi, Van Bui, Trey Hamilton, Didier Lootens
With the increasing use of pumping to place concrete, the development and refinement of the industry practice to ensure successful concrete pumping is becoming an important need for the concrete construction industry. To date, research on concrete pumping
One approach to increasing the sustainability of concrete construction is to replace a significant portion of the ordinary portland cement (OPC) with a supplementary cementitious material, such as fly ash. This paper presents mixture proportions and
Edward Garboczi, Aaron Forster, Jan Miller, Chen-Luh Lin, Cesar Chan, Kumar Natesaiyer, David Song, Suman Sinha-Ray
A combined computational/experimental materials science technique was developed for acquiring the structure of a rigid organic foam (ROHACELL) using X-ray computed tomography with appropriate image analysis, computing the elastic moduli using large-scale
Christopher C. White, Kar T. Tan, Donald L. Hunston, Aaron M. Forster, Deborah S. Jacobs
Accelerated and natural aging of safety films used in protective glazing systems was investigated by the use of Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy and tensile tests. Accelerated conditions involved simultaneous
Rick D. Davis, Yu-Chin Li, Michelle R. Gervasio, Yeon S. Kim
In this manuscript, natural materials were combined into a single pot to produce flexible, highly fire resistant, and bioinspired coatings on flexible polyurethane foam (PUF). In one step, PUF was coated with a fire protective layer constructed of a
Li xiodan, Zachary Grasley, Jeffrey W. Bullard, Edward Garboczi
A computational model has been developed that combines finite element methods with microstructure development simulations to quantitatively predict the viscoelastic/viscoplastic relaxation of cement paste due to intrinsic calcium silicate hydrate
Xiaodan Li, Zachary Grasley, Edward Garboczi, Jeffrey W. Bullard
Finite element procedures combined with microstructure development modeling are integrated to quantitatively predict the viscoelastic/viscoplastic relaxation of cement paste due to intrinsic calcium silicate hydrate viscoelasticity and microstructure
A common numerical task is to compute the effective elastic properties of a random composite material based on its microstructure by operating on a 3D digital image of the microstructure obtained via X-ray computed tomography (CT). The 3-D image is usually
Dale P. Bentz, Ahmad Ardani, Tim Barrett, Scott Z. Jones, Didier Lootens, Max A. Peltz, Taijiro Sato, Paul E. Stutzman, Jussara Tanesi, Jason Weiss
Limestone (calcium carbonate) has long been a critical component of concrete, whether as the primary raw material for cement production, a fine powder added to the binder component, or a source of fine and/or coarse aggregate. This paper focuses on the
Edward Garboczi, Zhiwei Qian, Erik Schlangen, Guang Ye
The mesostructures of mortar and concrete can be represented by a model consisting of particles (sand, gravel) embedded in a cement paste matrix. Traditionally, spheres have been used to represent aggregates because of their simplicity, although the
Yaghoob Farnam, Dale P. Bentz, Allison Hampton, Jason Weiss
This paper describes a series of experiments that were performed to assess the freeze-thaw behavior of mortar samples exposed to NaCl solutions. A low-temperature longitudinal guarded comparative calorimeter was used to perform cyclic freeze-thaw testing
Polymer nanocomposites are increasingly used in outdoor structures. However, polymers are susceptible to degradation by solar ultraviolet (UV) radiation, which potentially releases nanofiller during polymer nanocomposites' life cycle. Such release may pose
The objective of this study was to investigate how the heterogeneity due to nanoparticle dispersion of polymeric coatings affects surface morphological changes during ultraviolet (UV) exposure under different weathering conditions. Three types of nano
The deterioration of stone and brick architecture or sculpture often involves damage caused by moisture. The feasibility of a non-destructive testing (NDT) method based on prompt gamma neutron activation (PGNA) for measuring the element hydrogen as an
Emilio Hernandez-Bautista, Dale P. Bentz, Sadoth Sandoval-Torres, Prisciiano Cano Barrita
Steam curing under atmospheric pressure is used routinely in the precast concrete industry because of the increase in compressive strength up to 70 % obtained in only one day. However, this process requires high-energy consumption to maintain a constant
Emilio Hernandez-Bautista, Dale P. Bentz, Sadoth Sandoval-Torres, Prisciiano Cano Barrita
The process of accelerated curing of pre-cast concrete consists in increasing the temperature within a saturated water vapor atmosphere during several hours. In this process, the cement hydration has a significant importance in the thermal behavior of
An analytical full wave model of parallel, randomly dispersed carbon nanotubes (CNTs) embedded in a dielectric slab was developed to calculate the electromagnetic scattering from simple but non-trivial CNT composites. The model focuses on empty and metal
Bulk oxide determinations from two pairs of ASTM C150 portland cements are used to calculate precision and accuracy values for X-ray fluorescence (XRF) by both the fused glass bead and the pressed powder sample preparation methods. The first pair of
Dale P. Bentz, W. S. Guthrie, Scott Z. Jones, Nicos Martys
The prediction of concrete service life is of paramount importance for upgrading our nations built infrastructure. Although computer models for predicting the service life of reinforced concrete exposed to chlorides (e.g., road salts) have been developed