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Pichet Sahachaiyunta, Kittisak Pongpaisanseree, Jeffrey W. Bullard, Paul E. Stutzman, Edward Garboczi, Wilasa Vichit-Vadakan
The cement industry is moving toward customized commodity products, requiring plants that were built to consistently produce thousands of tons of one product each day to now be versatile enough to fine-tune multiple products that meet both industry
Igor de la Varga, Javier Castro, Dale P. Bentz, Jason Weiss
Sustainability has become an important issue in the concrete industry in recent years. One way to make concrete more sustainable is through the replacement of portland cement clinker with alternative cementitious materials such as fly ash. While fly ash is
Zachary Grasley, Jones Christopher, X Li, Edward Garboczi, Jeffrey W. Bullard
In order to effectively predict the mechanical properties of concrete and other cementitious materials, it is useful to understand the properties and deformation mechanisms on the nano-metric length scale. Through a combined analytical, experimental, and
There are diverse material science problems concerned with how the presence of a low concentration of particulate inclusions having mechanical properties distinct from the matrix in which they are placed influences the elasticity of the resulting composite
In this study the hydration kinetics of four different types of cements during early ages were investigated by both chemical shrinkage and isothermal calorimetry tests. Chemical shrinkage tests were performed at both different temperatures and pressures
Jason Weiss, Dale P. Bentz, Anton Schlinder, Pietro Lura
It is often said that there are two types of concrete: concrete that has cracked and concrete that is going to crack. Unfortunately, this is true all too frequently. Many of these unwanted cracks develop shortly after the concrete is placed and in addition
Jeffrey Thomas, Joseph J. Biernacki, Jeffrey W. Bullard, Shashank Bishnoi, Jorge S. Dolado, George W. Scherer, Andreas Luttge
This review endeavors to summarize the past 40 years or so of progress towards the development of mathematical models for understanding and predicting cement hydration behavior. A complete and accurate model of hydration would enable materials engineers
Kambiz Raoufi, John Schlitter, Dale P. Bentz, Jason Weiss
This study used a finite element model to examine how the properties of cementitious mortar are related to the rate of stress development in the dual ring test. The results of this investigation are used to explain the thermal cracking behavior of mixtures
Robert J. Flatt, George W. Scherer, Jeffrey W. Bullard
Cement hydration continues to have an intriguing character, surrounded as it is by a number of intensively debated questions. Among the unresolved issues is the reason why hydration stops at a relative humidity of about 80%, even though the system still
ASTM C1585 is commonly used to determine the absorption and rate of absorption of water in unsaturated hydraulic cement concretes. ASTM C1585 preconditions the samples for a total of 18 days. Unfortunately however, the range of relative humidities that can
The connectivity of the porosity in cement-based materials has an impact on material durability, the interpretation of experimental measurements such as chemical shrinkage, and the timing of curing operations. While several techniques have been used to
Scarification and overlay (SO) procedures are often performed on concrete bridge decks to minimize the corrosion of reinforcing steel due to chloride ingress. Given the need to develop guidelines for the initial timing of SO treatments, the objectives of
The mechanical ASTM sieve analysis and roundness measurement methods are traditionally used for characterization of the glass beads utilized in traffic markings. In recent years, computerized optical testing is gaining more attention. In this study, the
We argue that only an approach rooted in fundamental, mechanistic models of concrete materials offers a viable path for handling the enormous number of new variables that are being introduced as new materials are added to the design space, and as new
Jeffrey W. Bullard, Edward Garboczi, William L. George, Nicos Martys, Steven G. Satterfield, Judith E. Terrill
Supercomputers are renowned for being used on grand challenge problems like global weather patterns, nuclear device virtual testing, galaxy formation, unraveling molecular structure - and now concrete! Why do the mysteries of concrete form this kind of a
Alejandro Duran-Herrera, Cesar Juarez, P Valdez, Dale P. Bentz
This article presents results of an experimental research work oriented to develop practical tools for the regional concrete industry, as well as to illustrate the potential benefits of the synergistic effect of an ASTM C 618 Class F fly ash (FA) produced
Edward Garboczi, Sinan T. Erdogan, Yang Lu, Xuefeng Liu, Mircea Grigoriu
The shape of particles often plays an important role in how they are used and in the properties of composite systems in which they are incorporated. When building models of systems that include real particles, it is often of interest to generate new
The three dimensional (3-D) shape of a fairly broad size range of the particles of the lunar regolith simulant JSC-1A was characterized. After wet screening with water, the size classes that were kept and investigated were: those retained on a 300
John Schlitter, Andrew Senter, Dale P. Bentz, Tommy Nantung, Jason Weiss
The standard restrained ring test (ASTM 1581-04) is a simple, economical method to evaluate a concrete mixture s susceptibility of shrinkage cracking. Unfortunately, the test only provides restraint against samples that shrink and can not be used to
Javier Castro, Ryan Henkensiefken, Tommy Nantung, Dale P. Bentz, Jason Weiss
The increased propensity for shrinkage cracking in low water-to-cement ratio (w/c) concrete has resulted in the development of new methods that can reduce the risk of early-age cracking, including internal curing. Internal curing can use water-filled
Sara Laustsen, Dale P. Bentz, Marianne Hasholt, Ole M. Jensen
This paper describes how X-ray computed tomography (CT) scanning can be used to determine the void distribution in hardened concrete. Three different approaches are used to analyse a binary data set created from CT measurement. One approach classifies a
Milani S. Sumanasooriya, Dale P. Bentz, Narayanan Neithalath
Transport properties of porous materials such as pervious concretes are inherently dependent on a variety of pore structure features. Empirical equations are typically used to relate the pore structure of a porous material to its permeability. In this
L Holzer, R Flatt, S.T. Erodgan, Jeffrey W. Bullard, Edward Garboczi
Portland cement powder has a wide particle size distribution, from approximately 0.1 υm to 60 υm. This wide powder size distribution arises via the grinding of much larger clinker particles in fact, several percent of the world s energy expenditures are
Narayanan Neithalath, Dale P. Bentz, Milani S. Sumanasooriya
Pervious concrete is receiving renewed interest as a sustainable construction material for parking lots, sidewalks, and low-traffic-volume roads. A key characteristic of this material is its coarse porosity, achieved by omitting the fine aggregates from a
The mechanical ASTM sieve analysis and roundness measurement methods are traditionally used for characterization of the glass beads utilized in traffic markings. In recent years, computerized optical testing of the glass beads has been increasingly used as