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The mineralogical and microstructural changes that occur in cementitious systems during hydration are summarized. The discussion concentrates on changes that may occur in iso-thermal systems that do not interact with the environment. The discussion
Stephanie S. Watson, Tarek Marray, Yongyan Pang, Li Piin Sung
Metal oxide fillers, such as titanium dioxide (TiO2) are commonly used in building and construction applications and are added to increase the opacity and/or to improve the mechanics of a coating. However, their photoreactivity can contribute to
Andrew J. Allen, Jeffrey J. Thomas, Hamlin M. Jennings
Microstructure development and the kinetics of hydration of pure tricalcium silicate (C3S) and CaCl2-accelerated C3S pastes were investigated by performing isothermal calorimetry and in situ small-angle neutron scattering (SANS) measurements on parallel
Kenneth A. Snyder, Paul E. Stutzman, Jacob Philip, David W. Esh
The hydration products of varying proportions of portland cement, fly ash, ground granulated blast furnace slag, and silica fume in blended systems were identified and quantified. The proportion of portland cement varied from 100 % down to 10 %. The
The purpose of this study is to develop relevant metrology to measure the appropriate structure-property relationship at a proper length scale to understand the interplay between nanoparticle and polymeric matrix. In this paper, we present the preliminary
Jeffrey W. Bullard, Paul E. Stutzman, Luis M. Ordonez-Belloc, Edward J. Garboczi, Dale P. Bentz
The NIST-Industry Virtual Cement and Concrete Testing Laboratory (VCCTL) Consortium has developed an integrated software package for performing simulations of a number of engineering test measurements, including isothermal calorimetry, adiabatic
Dale P. Bentz, Edward J. Garboczi, Nicos Martys, Kenneth A. Snyder, W. S. Guthrie, Konstantinos Kyritsis, Narayanan Neithalath
The transport properties of concrete are critical to its field performance. Commonly encountered degradation mechanisms are dependent on ionic diffusivity, sorptivity, and permeability. In this paper, virtual testing of two of these concrete transport
Ryan Henkensiefken, Javier Castro, Dale P. Bentz, Tommy Nantung, Jason Weiss
The increased propensity for shrinkage cracking in low w/c concrete has spawned the development of new technologies that can reduce the risk of early-age cracking. One of these is internal curing. Internal curing uses saturated lightweight aggregate to
Nicos Martys, William L. George, Didier Lootens, Pascal Hebraud
Spatio-temporal correlations in start-up flows of attractive colloids are explored by numerical simulations. The suspension is first allowed to flocculate during a time tw, then the stress necessary to induce its flow is computed. Whereas at low volume
Organofunctionalized montmorillonite clays (MM) have been prepared with ammonium cations having a distribution of alkyl chain lengths. Relative to clays treated with alkylammonium cations having no distribution of chain lengths, the ultimate tensile stress
The influence of water-to-cement mass ratio (w/c) on early-age properties of cement-based materials is investigated using a variety of experimental techniques. Properties that are critical to the early-age performance of these materials are tested
Ryan Henkensiefken, Javier Castro, Haejin Kim, Dale P. Bentz, Jason Weiss
Internal curing (IC) provides a set of water reservoirs within the concrete to prevent self-desiccation and promote hydration. While early research in this area focused on reductions in early-age deformation and cracking, recent efforts have demonstrated
Li Piin Sung, Dongmei Zhe, Aaron M. Forster, Peter Krommenhoek, Nancy J. Lin, Sheng Lin-Gibson
Investigation on the effect of nano-silica on the effect of nano-silica on the surface morphology and mechanical properties has been carried out on two-dimensional (2D) gradient polymer-silica composite samples varied in chemical composition (e.g., filler