Comparative Study of Methods to Measure the Density of Cementitious Powders

Helsel, Michelle A.; Ferraris, Chiara F.; Bentz, Dale P.

doi:10.1520/jte20150148

Cited by 28 publications

(12 citation statements)

References 1 publication

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“…Now we first compared the elastic parameters of our biogenic CaCO 3 to those of the limestone cement. Limestone cement typically has a density of 2700-2800 kg/m 3 , the bulk modulus of elasticity of 69.8 GPa, the Young's modulus of 79.6 GPa, the shear modulus of 30.4 GPa and Poisson's ratio of 0.31 43,44 . According to Tables 2 and 3, the elastic moduli of CaCO 3 obtained from strain WH when using calcium nitrate and calcium chloride as a calcium source is comparable to those of the limestone cement.…”

Section: Discussionmentioning

confidence: 99%

Investigating mechanical properties and biocement application of CaCO3 precipitated by a newly-isolated Lysinibacillus sp. WH using artificial neural networks

Ekprasert

Fongkaew

Chainakun

et al. 2020

Sci Rep

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A newly-isolated Lysinibacillus sp. strain WH could precipitate CaCO3 using calcium acetate (Ca(C2H3O2)2), calcium chloride (CaCl2) and calcium nitrate (Ca(NO3)2) via non-ureolytic processes. We developed an algorithm to determine CaCO3 crystal structures by fitting the simulated XRD spectra to the experimental data using the artificial neural networks (ANNs). The biogenic CaCO3 crystals when using CaCl2 and Ca(NO3)2 are trigonal calcites with space group R3c, while those when using Ca(C2H3O2)2 are hexagonal vaterites with space group P6522. Their elastic properties are derived from the Voigt–Reuss–Hill (VRH) approximation. The bulk, Young's, and shear moduli of biogenic calcite are 77.812, 88.197, and 33.645 GPa, respectively, while those of vaterite are 67.082, 68.644, 25.818 GPa, respectively. Their Poisson’s ratios are ~ 0.3–0.33, suggesting the ductility behavior of our crystals. These elastic values are comparable to those found in limestone cement, but are significantly larger than those of Portland cement. Based on the biocement experiment, the maximum increase in the compressive strength of Portland cement (27.4%) was found when Ca(NO3)2 was used. An increased strength of 26.1% was also found when Ca(C2H3O2)2 was used, implying the transformation of less-durable vaterite to higher-durable calcite. CaCO3 produced by strain WH has a potential to strengthen Portland cement-based materials.

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Section: Discussionmentioning

confidence: 99%

Investigating mechanical properties and biocement application of CaCO3 precipitated by a newly-isolated Lysinibacillus sp. WH using artificial neural networks

Ekprasert

Fongkaew

Chainakun

et al. 2020

Sci Rep

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“…This value quantifies the absolute number of building units in a given amount of crystal volume, complementing the information regarding their relative amounts obtained from other characterization methods. For this purpose, the best available analyses are gas pycnometry, [44,45] mercury porosimetry, [46] and mass correlation spectroscopy. [47,48] So far, we have outlined a comprehensive albeit not necessarily complete list of analytical techniques and stressed the importance of their complementarity in gathering different types of information.…”

Section: Connection Completeness (κ) Describes the Degree Of Architecmentioning

confidence: 99%

Section: Aging Assessment: Experimental Tools For Analyzing Architectmentioning

confidence: 99%

Circumventing Wear and Tear of Adaptive Porous Materials

Canossa

Wuttke

2020

Adv Funct Materials

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The assessment of the architectural stability of molecular porous materials is not yet a common practice, but critical to their understanding and development. The conformational adaptation of porous materials to guest binding and other chemical dynamics poses a risk of architectural damage, leading to performance deterioration during their prolonged usage. The deformation of the framework backbone and the disconnection of building units are driven by chemical, mechanical, and thermal perturbations, and can be quantitatively described by the term connection completeness. Analytical means that can be used to measure this parameter are presented in order to provide a standard, practical protocol for evaluating architectural damage made to framework materials. Preventive and remedial strategies are proposed for enhancing the architectural integrity of frameworks without compromising their functional mechanisms, paving the way to the design of robust yet adaptive materials. In this way, the discussion on architectural stability is initiated, and readers are encouraged to carefully characterize molecular porous materials for a better understanding of their structure-property relationship.

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“…In addition to using the current standard method, ASTM C188-14 (Le Chatelier method), a helium pycnometer was also used to provide more consistency. A study at NIST compared the two methods for the limestone and other powders, which concluded by proposing that the helium pycnometer be a new standard method for density measurements of hydraulic cement [15]. The pycnometer provides more efficient density measurements since the testing fluid is a gas (helium) rather than a liquid (kerosene or alcohol for example); therefore, the pycnometer is capable of filling more air voids.…”

Section: Characteristics Of the Limestone And Corn Syrupmentioning

confidence: 99%

Re-Certification of SRM 2492: Bingham Paste Mixture for Rheological Measurements

Ferraris¹,

Olivas²,

Guthrie³

et al. 2015

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Rheological measurements are often performed using a rotational rheometer. In this type of rheometer, the tested fluid is sheared between two surfaces, one of which is rotating [1]. Usually, an angular velocity is imposed on the fluid (through the rotating surface) and this angular velocity determines the shear rate the fluid is subjected to. The response of the material is monitored by the measurement of the resultant torque on the shaft of the rheometer; this torque can then be converted to shear stress. In order to calibrate a rheometer, a standard oil of known viscosity should be tested in the rheometer to verify that the instrument is operating correctly. However, these standard oils are expensive; which makes it impractical for use in calibrating with the rheometer with a large capacity as needed for concrete. Additional, these standard oils that are not suspensions (i.e. they do not have solid particles suspended in the media), and thus using them may not capture some issues that may occur in a suspension rheology. Therefore, a relatively inexpensive, reference material is needed that incorporates aggregates for concrete rheometers. As concrete and mortar are non-Newtonian, the reference material should also be non-Newtonian. This report follows the development and serves as re-certification of a Standard Reference Material (SRM) for cement paste [2]. A multiscale approach will be utilized to develop SRMs for mortar and concrete in the future. The SRM 2492 will be the matrix fluid for a mortar SRM that will in turn become the matrix fluid for a concrete SRM. The report SP 260-174 Rev.2012 [2] describes how this SRM 2492, a "Bingham Paste Mixture for Rheological Measurements" was developed and provides all the details on the various ingredients. After an inter-laboratory study under the sponsorship of the American Concrete Institute (ACI) committee 238, Workability of Fresh Concrete, it was found that the instructions provided to prepare the SRM were inadequate to obtain reproducible data in all laboratories. Thus after establishing a better preparation method, new instructions were drafted and it was found that the certified values were no longer valid. Thus, it was necessary to redo a series of testing to obtain a new certified value. This report provides all measurements obtained, the calculation of the new rheological characteristics and the statistical analyses. This is report is the third edition of the report and is based on new data using a different method for preparing the mixture (see section 3.3

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Comparative Study of Methods to Measure the Density of Cementitious Powders

Cited by 28 publications

References 1 publication

Investigating mechanical properties and biocement application of CaCO3 precipitated by a newly-isolated Lysinibacillus sp. WH using artificial neural networks

Investigating mechanical properties and biocement application of CaCO3 precipitated by a newly-isolated Lysinibacillus sp. WH using artificial neural networks

Circumventing Wear and Tear of Adaptive Porous Materials

Re-Certification of SRM 2492: Bingham Paste Mixture for Rheological Measurements

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