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Dale P. Bentz, Scott Z. Jones, Paul E. Stutzman, Joshua Arnold, Michael Boisclair, Paul Rothfeld, Jussara Tanesi, Haejin Kim, Jose Munoz, Mengesha Beyene
While the influence of paste properties on concrete performance has been extensively studied and in many cases reduced to quantitative relationships, that between aggregate characteristics and concrete performance has not been investigated in detail. Based
This chapter reviews ash quality and performance issues, with special emphasis on air entrainment and early-age performance. Recent developments in testing procedures are reviewed and recommendations are provided for standardized testing. One of the key
The incorporation of limestone powder in cementitious binders for concrete in the U.S. has become a subject of renewed interest, in part due to the ongoing sustainability movement. In addition to accelerating the early age hydration reactions of
Edward J. Garboczi, David F. Plusquellic, Robert D. McMichael, Virgil Provenzano, Paul E. Stutzman, Jack T. Surek, Shin G. Chou, Shuangzhen Wang
Virtually every corrosion detection method reports only the presence of a material phase denoting probable corrosion, not its spectral signature. A signature specific to the type of iron oxide corrosion would not only confirm the presence of corrosion but
Edward J. Garboczi, Kenneth A. Snyder, Rolands Cepuritis, Stefan Jacobsen
The shape of concrete aggregate fines, with particle sizes between 3 µm and 250 µm, produced by high-speed vertical shaft impact (VSI) crushing of 10 different rock types from quarries in Norway, has been studied by both dynamic image analysis (DIA), which
Catherine Lucero, Robert Spragg, Dale P. Bentz, Daniel S. Hussey, David L. Jacobson, Jason Weiss
A portion of the concrete pavements in the US have recently been observed to have premature joint deterioration. While this damage has been attributed to a wide variety of potential factors, it is hypothesized that one component of this damage can be
Tinh Nguyen, Elijah J. Petersen, Bastien T. Pellegrin, Justin M. Gorham, Thomas F. Lam, Minhua Zhao, Li Piin Sung
Carbon nanotubes (CNTs) are increasingly used in consumer and structural polymeric products to enhance a variety of properties. Under weathering, the polymer matrix will degrade and the nanofillers will potentially be released from the products, which
Dale P. Bentz, Chiara F. Ferraris, Scott Z. Jones, Didier Lootens, Franco Zunino
Developing functional concrete mixtures with less ordinary portland cement (OPC) has been one of the key objectives of the 21st century sustainability movement. While the supply of many alternatives to OPC (such as fly ash or slag) may be limited, those of
Edward J. Garboczi, Chiara F. Ferraris, Rolands Cepuritis, Stefan Jacobsen, Bjorn Sorensen
The study investigates which measurement methods are best applicable to crushed concrete aggregate fines smaller than about 250 µm to determine particle size distribution (PSD) and specific surface area: wet-method laser diffraction (LD), X-ray
Alex Olivas, Michelle A. Helsel, Nicos Martys, Chiara C. Ferraris, William L. George, Raissa Ferron
The conclusion of international studies was that the optimal approach to calibrate concrete rheometers would be to develop a non-Newtonian standard reference material (SRM) that contained inclusions similar in size to aggregates used commonly in concrete
Edward Garboczi, Rolands Cepuritis, Stefan Jacobsen
We studied the 3-D shape of concrete aggregate fines (3 µm to 250 µm) produced by high-speed VSI crushing of rock types from 10 different quarries representing a wide range of local Norwegian geological variety with respect to mineralogy and mechanical
Hadi S. Esmaeeli, Yaghoob Farnam, Dale P. Bentz, Pablo Zavattieri, Jason Weiss
This paper presents a one-dimensional finite difference model that was developed to describe the freeze-thaw behavior of mortar containing deicing salt solution. The model is used to predict the temperature and the heat flow for mortar samples during
Mauro Zammarano, Shonali Nazare, John R. Shields, Kathleen M. Hoffman, Rick D. Davis
A durable and flexible silicone-based backcoating (halogen and formaldehyde free) is applied to the backside of an otherwise smoldering-prone and flammable fabric. When exposed to fire, cyclic siloxanes (produced by thermal decomposition of the backcoating
Cold weather concreting often requires the use of chemical accelerators to speed up the hydration reactions of the cement, so that setting and early-age strength development will occur in a timely manner. While calcium chloride (dihydrate CaCl2∙2H2O) is
To compute light scattering or any other quantity for a random particle, one needs to mathematically know the shape of the particle. For regular particles like spheres and ellipsoids, this is straightforward to do. For random particles, with realistic
Alex Olivas, Chiara C. Ferraris, Brian Lang, Jennifer Richter, Raissa Ferron
Cement-based materials (e.g. cement paste, mortar and concrete) are complex rheological fluids that display time-dependent and shear-dependent rheological behavior. Over the years, various concrete rheometers have been proposed and made available
Richard A Livingston, Carol A. Grissom, Edward Vicenzi, Zoe Weldon-Yochim, Nicole Little, Janet Douglas, Alexandre Fowler, Cara Santelli, Dorothea Macholdt, Diana Ortiz-Montalvo, Stephanie S. Watson
Bluish black, highly adherent patches have been observed growing on the Seneca sandstone of the Smithsonian Castle in Washington, DC. They are significantly enriched in Mn compared to the underlying sandstone, by a factor of 100, which suggests that
We study the diffusion of chloride ions in hardened cement paste (HCP) under steady-state conditions and accounting for the highly heterogenous nature of the material. The HCP microstructures are obtained through segmentation of X-ray images of real
Li Piin Sung, Karthik V. Pillai, Patrick Gray, Reiner Bleher, Timothy V. Duncan
Concomitant with the development of polymer nanocomposite (PNC) technologies across numerous industries is an expanding awareness of the uncertainty with which engineered nanoparticles embedded within these materials may be released into the external
Edward Garboczi, Isamar Rosa, Michael Lepech, Henning Roedel, David Loftus
This work focuses on a novel class of composites that can be produced extraterrestrially, or in situ, by desiccating a mixture of soil, water, and protein binder to create a strong, versatile material. To date, experimental tests of mechanical properties
Chiara F. Ferraris, Nicos Martys, William L. George, Edward J. Garboczi, Alex Olivas
The calibration of rheometers to determine the rheological properties of cement based materials ranging from cement paste to concrete cannot be done using standard oils as they are cost prohibitive and do not possess sufficient granularity to test slip
Li Piin Sung, Justin Gorham, Deborah Jacobs, Savelas A. Rabb, Lee L. Yu, Tinh Nguyen
Temperature effect on the kinetics of photodegradation, surface accumulation of nanoparticles, and nanoparticle release in an epoxy nanocoating exposed to ultraviolet light (UV) was investigated. A model epoxy coating containing 5 % untreated nanosilica
The importance of particle shape in affecting the behaviour of powders and other particulate systems has long been recognised, but until fairly recently particle shape information has been rather difficult to obtain and use compared to its more well-known
Zeeshan Ahmed, Matthew Skorski, Jake Esenther, Abigail E. Miller, Hartings Mathew
3-D printing has captured the imagination of many and has enabled a culture of makers. The ability of this process to generate intricate structures from polymer filaments has led to interest from home enthusiasts as well as laboratory scientists. From a
Previous research has demonstrated a linear relationship between compressive strength (mortar cubes and concrete cylinders) and cumulative heat release normalized per unit volume of (mixing) water for a wide variety of cement-based mixtures at ages of 1 d