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Neubauer, C.M.; Bergstrom, T. B.; Sujata, K.; Xi, Yunping; Garboczi, Edward J.; Jennings, Hamlin M.

doi:10.1023/a:1018682404655

Cited by 32 publications

(3 citation statements)

References 24 publications

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“…As noted above, D e is an effective term reflecting diffusivities of the aggregate and cement phase. In addition, greater porosity and, hence, diffusivity within interfacial transition zones (ITZs), the latter depending upon aggregate content and size, may contribute 20, 27–31. However, many literatures also reported 32–36 that lightweight aggregates (LWAs) with a porous surface layer have been noted to produce a dense ITZ microstructure that is equivalent to that of the bulk cement paste, as opposed to the more porous ITZs that typically surround normal weight aggregates.…”

Section: Resultsmentioning

confidence: 99%

Correction of chloride threshold concentration and time‐to‐corrosion due to reinforcement presence

Hartt

2011

Materials & Corrosion

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Reinforcement presence affecting corrosion threshold concentration, C t , determination and time-to-corrosion, T i , has been investigated. Elevated C t and decreased T i due to reinforcement physical obstruction on the path of chloride ingression into concrete has been examined with finite element modeling. Results indicated that reinforcement with larger size, better corrosion resistance, less cover thickness, or a more flat leading edge causes more pronounced T i reduction. Experimental results exposed aggregate content discrepancy within reinforced bar vicinity zone. According to this finding, a multi-shell chloride diffusion model, in which specific chloride ion diffusivity in each shell surrounding bar presents, is proposed. The C t results of proposed model are discussed along with those acquired from traditional onedimensional model, in which chloride diffusion follows Fick's second law without considering reinforcement presence, and two-dimensional model with the effect of reinforcement physical obstruction regarded.

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Section: Resultsmentioning

confidence: 99%

Correction of chloride threshold concentration and time‐to‐corrosion due to reinforcement presence

Hartt

2011

Materials & Corrosion

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“…At a lower-length scale level, experimental techniques such as nanoindentation [24][25][26], environmental scanning electron microscopy [27], and ultrasonic pulse velocity [22] have been used in an attempt to understand the variation in the local mechanical properties and its correlation to the phase distribution and the interfacial zones in cement pastes. In these techniques, the elastic properties can be considered to be isotropic in the sense of a statistical average that requires multiple points to be characterized to calculate the averages.…”

Section: Introductionmentioning

confidence: 99%

Constitutive Stiffness Characteristics of Cement Paste as a Multiphase Composite System—A Molecular Dynamics-Based Model

Espinosa

Hodo

Murillo

et al. 2017

Journal of Engineering Materials and Technology

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Cement paste is a material with heterogeneous composite structure consisting of hydrated and unhydrated phases at all length scales that varies depending upon the degree of hydration. In this paper, a method to model cement paste as a multiphase system at molecular level for predicting constitutive properties and for understanding the constitutive mechanical behavior characteristics using molecular dynamics is presented. The proposed method creates a framework for molecular level models suitable for predicting constitutive properties of heterogeneous cement paste that could provide potential for comparisons with low length scale experimental characterization techniques. The molecular modeling method followed two approaches: one involving admixed molecular phases and the second involving clusters of the individual phases. In particular, in the present study, cement paste is represented as two-phase composite systems consisting of the calcium silicate hydrate (CSH) phase combined with unhydrated phases tricalcium silicate (C3S) or dicalcium silicate (C2S). Predicted elastic stiffness constants based on molecular model representations employed for the two phases showed that, although the individual phases have anisotropic characteristics, the composite system behaves as an isotropic material. The isotropic characteristics seen from two-phase molecular models mimic the isotropic material nature of heterogeneous cement paste at engineering scale. Further, predicted bulk modulus of the composite system based on molecular modeling is found to be high compared to the elastic modulus, which concurs with the high compression strength of cement paste seen at engineering length scales.

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“…Literatures [2,3,4] studied the characteristics and application range of ESEM. ESEM was be used to study the shrinkage of cement paste microstructure in literature [5] and been found that the shrinkage decreased with the increase of age and the reduction of water-cement ratio. Literature [6] studied the shrinkage of cement paste at 3000 rate with the application of image matching.…”

Section: Introductionmentioning

confidence: 99%

Research on Shrinkage and Cracking of Cement Paste Based on Environmental Scanning Electron Microscope

Sui

2011

AMR

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In order to study the shrinkage characteristics of cement paste, environmental scanning electron microscope was used to observe the microstructure shrinkage of cement paste and cement mortar under different humidity. The results showed that : with the relative humidity decreased from 80% to 10%, the shrinkage cracking of paste microstructure appeared in different degree and increased continuously,also the regression analysis showed the relative humidity and shrinkage was conical relationship.

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Untitled

Cited by 32 publications

References 24 publications

Correction of chloride threshold concentration and time‐to‐corrosion due to reinforcement presence

Correction of chloride threshold concentration and time‐to‐corrosion due to reinforcement presence

Constitutive Stiffness Characteristics of Cement Paste as a Multiphase Composite System—A Molecular Dynamics-Based Model

Research on Shrinkage and Cracking of Cement Paste Based on Environmental Scanning Electron Microscope

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