Buscar
Mostrando ítems 61-70 de 96
The use of mo and cu monochromatic radiations for quantitative phase analysis: study of the accuracy
(2016-06-27)
Cement hydration is a very complex process in which crystalline phases are dissolving in water and after supersaturation hydrated crystalline and amorphous phases precipitate. Great efforts are being made to develop ...
Quantitative phase Analisis: A comparative study of Mo and Cu strictly monochromatic radiations
(2016-06-27)
A comparison of the Rietveld quantitative phase analyses (RQPA) obtained using Cu-Kα1, Mo-Kα1, and synchrotron strictly monochromatic radiations is presented. The main aim is to test a simple hypothesis: high energy ...
Structure-properties correlations in divalent metal phosphonates
(2016)
Crystalline metal phosphonates may offer acidic sites, structural flexibility and guest molecules (H2O, heterocyclics, etc.) which can act as proton carriers. In addition, some frameworks are also amenable for post‐synthesis ...
Clinkering and early age hydration characterization of Belite-Alite Calcium Sulfoaluminate (BACSA) cements
(2015-10-26)
In this work, four BACSA clinkers with different compositions (belite ~ 70-55 wt %, alite ~ 10-15 wt % and ye’elimite ~ 10-15 wt %) were synthesized (at laboratory scale). Lime, gypsum, kaolin and sand were used as raw ...
Pair distribution function studies in cementitious systems
(2017-10-24)
The analysis of amorphous/nanocrystalline phase(s) within cement matrices that contain high amounts of crystalline phase(s) is very challenging. Synchrotron techniques can be very useful to characterize such complex samples.1 ...
Synthesis and scaled-up of non-active and active Belite-Alite-Ye'elimite clinker (BAY)
(2017-05-17)
Ordinary Portland cement (OPC) is an environmentally contentious material, as for every ton of OPC produced, ~0.97 tons of CO2 are released. This opens the need of designing new formulations of cements formed by low calcite ...
Hydration study of alite-ye’elimite-anhydrite phases associated to BAY cement
(2017-10-18)
An alternative to decrease CO2 emissions from OPC production consists on the development of a new kind of eco-cements composed by less calcite demanding phases, such as belite and ye'elimite. That is the case of ...
Tuning Proton Conductivity in A Multifunctional Calcium Phosphonate Hybrid Framework
(2014-06-25)
Multi-chelating phosphonate ligands are organic linkers alternative to polycarboxylates and other ligands providing synthetic access to a number of thermally- and chemically-stable MOFs [1]. Metal phosphonates are amenable ...
Effect of different retarders on the hydration of calcium sulfoaluminate eco-cement pastes
(2014-07-09)
The manufacture of Calcium SulfoAluminate (CSA) cements is more environmentally friendly than that of OPC [1] as their production releases up to 40% less CO2 than the latter. The main performances of CSA cements are fast ...
X-ray powder diffraction applied to cement related phases: in-situ and high resolution applications
(2014-07-03)
XRPD is a powerful tool for material characterization in general, and for in-situ studies of chemical processes in particular. The use of an intense X-ray source, .i.e. synchrotron X-rays, coupled with fast X-ray detection ...