Properties of high-performance concrete containing shrinkage-reducing admixture

Folliard, Kevin J.; Berke, Neal S.

doi:10.1016/s0008-8846(97)00135-x

Cited by 149 publications

(52 citation statements)

References 4 publications

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“…Because diffusion coefficients should be inversely proportional to the viscosity of the pore solution (Gordon 1937), one might expect that the diffusion coefficients in concretes prepared with SRAs could be favorably reduced by a factor of about 1.5 relative to those in concrete prepared without any SRA additions. This expectation must be contrasted against the experimental observation of Folliard and Berke (1997), who noted "no significant effect of SRA addition on the rapid chloride permeability of concrete." However, because the rapid chloride permeability test actually assesses electrical conduction and not ionic diffusion, it may be insensitive to the change in viscosity and its effect on the inherent diffusivity (physical movement) of ions in the bulk pore solution.…”

Section: Resultsmentioning

confidence: 74%

“…Originally introduced in Japan in the 1980s (Sato et al 1983), these materials became commonplace in the U.S. by the late 1990s (Folliard andBerke 1997, Nmai et al 1998). While the specific chemical compositions of the SRAs vary amongst manufacturers, they generally reduce the surface tension of the pore solution (or of distilled water) by as much as 50 % or more, at typical recommended addition rates.…”

Section: Introductionmentioning

confidence: 99%

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Influence of Shrinkage-Reducing Admixtures on Early-Age Properties of Cement Pastes

Bentz

2006

ACT

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Because most shrinkage-reducing admixtures (SRAs) significantly reduce the surface tension of a cement paste pore solution, they will naturally influence all physical properties and processes that are dependent in some way on surface tension. Such properties include internal relative humidity, capillary stresses, and freezing point depression, all via the Kelvin equation and its variants (Kelvin-Laplace, Gibbs-Thomson). Processes that will thus be strongly influenced by the presence of SRAs include drying, autogenous stress and strain development, and freezing. In this paper, experimental measurements of these processes in cement pastes and mortars with and without SRA additions will be presented in light of the Kelvin equation. The experimental measurements that are applied to early-age specimens include X-ray absorption measurements to quantify drying profiles, bulk mass loss measurements, measurements of internal relative humidity, assessments of autogenous deformation under sealed curing conditions, and low temperature calorimetry scans to quantify freezable water content. The results indicate that SRAs can provide benefits in several new applications beyond their conventional usage to reduce drying shrinkage.

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Section: Resultsmentioning

confidence: 74%

Section: Introductionmentioning

confidence: 99%

Influence of Shrinkage-Reducing Admixtures on Early-Age Properties of Cement Pastes

Bentz

2006

ACT

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“…In addition, the solubility of silymarin in FI (130.8 mg/mL) was closer to that in polysorbate 20 whose structure was similar with Cremophor EL (130 mg/mL (6)), which demonstrated that solubilization efficiency for silymarin in SMEDDS was similar to that in polysorbate 20 alone, thereby the safety was enhanced due to the fact that low content of emulsifier was used in SMEDDS. It was reported that the mechanism about solubilization of substance in microemulsion or micelle could be investigated by X-ray, UV, or nuclear magnetic resonance (25)(26)(27). As seen from Fig.…”

Section: Physicochemical Properties Of Silymarin In Microemulsionmentioning

confidence: 99%

Development of Silymarin Self-Microemulsifying Drug Delivery System with Enhanced Oral Bioavailability

Yuan

Huang

et al. 2010

AAPS PharmSciTech

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Abstract. The objective of this work was to develop a self-microemulsifying drug delivery system (SMEDDS) for improving oral absorption of poorly water-soluble drug, silymarin. The pseudo-ternary phase diagrams were constructed using ethyl linoleate, Cremophor EL, ethyl alcohol, and normal saline to identify the efficient self-microemulsification region. The particle size and its distribution of the resultant microemulsions were determined using dynamic light scattering. The optimal formulation with the best self-microemulsifying and solubilization ability consisted of 10% (w/w) of ethyl linoleate, 30% of Cremophor EL, and 60% of ethyl alcohol. The release of silymarin from SMEDDS was significantly faster than that from the commercial silymarin preparation hard capsule (Legalon®). The bioavailability results indicated that the oral absorption of silymarin SMEDDS was enhanced about 2.2-fold compared with the hard capsule in fasted dogs. It could be concluded that SMEDDS would be a promising drug delivery system for poorly water-soluble drugs by the oral route.

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“…Others have recognized that there is a relationship between surface tension and shrinkage reduction, [22][23][24][25][26] and Pease has shown a quantitative relationship between shrinkage coefficient and surface tension. 27 Kayello, et al identified 26 new structures using the I-QSPR strategy, these compounds will be henceforth described as I-QSPR compounds or the "designed" compounds.…”

Section: Resultsmentioning

confidence: 99%

An Application of Computer‐Aided Molecular Design (CAMD) Using the Signature Molecular Descriptor–Part 2. Evaluating Newly Identified Surface Tension‐Reducing Substances for Potential Use as Shrinkage‐Reducing Admixtures

et al. 2013

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In this study, the use of computer-aided molecular design (CAMD) is validated as a tool for enabling the discovery of new shrinkage-reducing compounds for possible use in portland cement composites and is framed as one of many multiscale modeling tools in a broad hierarchy of possibilities. Twelve additives were tested for their ability to inhibit shrinkage in Type I ordinary portland cement under both autogenous and drying conditions. The 12 additives included two commercial shrinkage-reducing admixtures (SRAs), two active ingredients of a commercial admixture [one of which was used to establish the quantitative structure-property relationships (QSPR)], two additional classified as potential SRA compounds based on the patent literature, four newly identified compounds predicted by using CAMD and an inverse quantitative structure-property relationship (I-QSPR), and two other compounds use to establish the QSPR relationship. The newly identified I-QSPR compounds were targeted for their ability to reduce the surface tension of water, a primary consideration for shrinkage-reducing activity. Results for both drying shrinkage and autogenous shrinkage indicate that the designed compounds perform similar to commercial admixtures, yet have different chemical functionalities. Hydration data and set measurements were also considered since selection of new SRAs is a multiparameter problem with many constraints. Thus, these newly identified shrinkage-reducing compounds can potentially provide additional options for use in portland cement concrete applications.

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Properties of high-performance concrete containing shrinkage-reducing admixture

Cited by 149 publications

References 4 publications

Influence of Shrinkage-Reducing Admixtures on Early-Age Properties of Cement Pastes

Influence of Shrinkage-Reducing Admixtures on Early-Age Properties of Cement Pastes

Development of Silymarin Self-Microemulsifying Drug Delivery System with Enhanced Oral Bioavailability

An Application of Computer‐Aided Molecular Design (CAMD) Using the Signature Molecular Descriptor–Part 2. Evaluating Newly Identified Surface Tension‐Reducing Substances for Potential Use as Shrinkage‐Reducing Admixtures

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