On the interpretation of low temperature calorimetry data

Kjeldsen, Ane Mette

doi:10.1617/s11527-007-9239-8

Cited by 25 publications

(21 citation statements)

References 11 publications

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“…This means that ice formation in pores with inlet constrictions depends on ice formation in the constrictions and that water in closed pores will be included in non-freezing water. All LTC data given in the following are derived from single experiments, as repetitions undertaken in connection with earlier work, using the same experimental setup, showed limited variability in the results [49] (a general discussion of the assessment of LTC data is also given in that study). The measured heat flow as a function of temperature is shown in Fig.…”

Section: Water and Porosity From Low-temperature Calorimetry Ltcmentioning

confidence: 94%

Microstructure engineering of Portland cement pastes and mortars through addition of ultrafine layer silicates

Lindgreen¹,

Geiker²,

Krøyer³

et al. 2008

Cement and Concrete Composites

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Section: Water and Porosity From Low-temperature Calorimetry Ltcmentioning

confidence: 94%

Microstructure engineering of Portland cement pastes and mortars through addition of ultrafine layer silicates

Lindgreen¹,

Geiker²,

Krøyer³

et al. 2008

Cement and Concrete Composites

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“…The differential PSDs with respect to pore volume were re-calculated as incremental PSD (IPSD v ). In the calculations, there was estimated contribution of individual kinds of pores: nanopores (V nano , S nano for R p \ 1 nm), mesopores (V meso , S meso for 1 nm \ R p \ 25 nm) and macropores (V macro , S macro for R p [ 25 nm) [11,[26][27][28][29][30][31]. The pores of nanosize radii (R \ 1 nm) were designated as the ''nanopores'' [11,27].…”

Section: N 2 Adsorptionmentioning

confidence: 99%

Application of differential scanning calorimetry to study porous structure of hydrothermally modified silicas

Charmas

Skubiszewska–Zięba

2017

J Therm Anal Calorim

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The paper presents the studies on determination of physicochemical and structural properties of hydrothermally treated (HTT) silica gel Si-60, using the differential scanning calorimetry (DSC) and N 2 adsorption methods. Modification was performed in overheated water vapours or under the liquid water layer using various sources of thermal energy (in the classical autoclave or in the high-pressure microwave reactor). The characteristics of porous structure were determined on the basis of low-temperature nitrogen adsorption/desorption isotherms and using the calorimetric data (DSC) of thermal effects of phase transition of water introduced inside pores of the studied materials. Great compatibility of the characteristics obtained by means of the above-mentioned methods was proved. As follows from the SEM analysis, during HTT silica is rebuilt resulting in great changes of surface morphology and porous structure of the materials. The range of these changes depends on both the applied system (water vapour/liquid water) and the kind of used energy (classical/microwave).

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“…vary considerably ranging from ±1.2; ?4.1/-3.3; ±10; ±11; ±15°C/h [5,6,[29][30][31]] to more rapid rates of ±24°C/h [20] and ±88°C/h [32] and ultra-rapid rates of ±120°C/h [16] and ±230°C/h [20]. The regime adopted was thus taken to represent a compromise.…”

Section: Electrical Measurements and Data Acquisitionmentioning

confidence: 99%

Conductivity/activation energy relationships for cement-based materials undergoing cyclic thermal excursions

et al. 2014

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The electrical conductivity of a range of concrete mixes, with and without supplementary cementitious materials (SCM), is studied through multiple cycles of heating and cooling over the extended temperature range -30/?70°C. When presented in an Arrhenius format, the experimental results display hysteresis effects at the lowtemperature end of the thermal cycle and, in those concretes containing supplementary cementitious materials at higher water/binder ratios, hysteresis effects were evident over the entire temperature range becoming more discernible with increasing number of thermal cycles. The depression in both the freezing and thawing point could be clearly identified and was used to estimate pore-neck and pore-cavity radii. A simplified approach is presented to evaluate the volumetric ratio of frozen pore water in terms of conductivity measurements. The results also show that the conductivity and activation energy of the concrete specimens were related to the water/binder ratio, type of SCM, physical state of the pore water and the thermal cycling regime.

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On the interpretation of low temperature calorimetry data

Cited by 25 publications

References 11 publications

Microstructure engineering of Portland cement pastes and mortars through addition of ultrafine layer silicates

Microstructure engineering of Portland cement pastes and mortars through addition of ultrafine layer silicates

Application of differential scanning calorimetry to study porous structure of hydrothermally modified silicas

Conductivity/activation energy relationships for cement-based materials undergoing cyclic thermal excursions

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