scispace - formally typeset
Search or ask a question
Topic

Calcium aluminates

About: Calcium aluminates is a research topic. Over the lifetime, 490 publications have been published within this topic receiving 9200 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: In this article, the TG and DTG curves of different Portland cement pastes (types I, II, III and G), with a water-to-cement ratio (W/C) equal to 0.5, were analyzed at different ages, at same operating conditions.
Abstract: The capture of CO2 and SO2 from industrial gas effluents has been done usually by lime-containing products. For this purpose, cement pastes also can be used, due mainly to their calcium hydroxide content formed during hydration. To select the best cement for this purpose, TG and DTG curves of different Portland cement pastes (types I, II, III and G), prepared with a water-to-cement ratio (W/C) equal to 0.5, were analyzed at different ages, at same operating conditions. The curves were transformed into respective cement calcined and initial mass basis, to have a common and same composition reference basis, for a correct quantitative hydration data comparison. This procedure also shows that there is an unavoidable partial drying effect of the pastes before starting their analysis, which randomly decreases the W/C ratio at which were prepared, which indicates that, when results are compared on respective paste initial mass basis, assuming that the ratio W/C has not changed, possible calculation errors may be done. Type I, II and G analyzed cements have shown similar hydration characteristics as a function of time, while the analyzed type III cement has shown a different hydration behavior, mainly due to its highest Al2O3 and lowest SO3 contents, promoting the formation of hydrated calcium aluminates, by the pozzolanic action of the excess of alumina, consuming Ca(OH)2, which final content at 28 days was the lowest one, among the hydrated cements.

15 citations

Journal ArticleDOI
TL;DR: The novel MTA, which consists of calcium silicates, calcium aluminates, and zirconium oxide, was designed to obtain fast-setting property and can achieve initial setting in 10 min and final setting in 15 min, which are much faster than commercial mineral trioxide aggregate.
Abstract: One of the main drawbacks that limits the application of mineral trioxide aggregate (MTA) in dental field is its long setting time. Mineral trioxide aggregate with accelerated setting properties and excellent chemical-physical and biological properties is still required. In this study, an innovative mineral trioxide aggregate, which consists of calcium silicates, calcium aluminates, and zirconium oxide, was designed to obtain fast-setting property. The optimized formulation can achieve initial setting in 10 min and final setting in 15 min, which are much faster than commercial mineral trioxide aggregate. In addition, the optimized fast-setting MTA showed adequate radiopacity and good biocompatibility. The ion concentrations after storage in water for 1 day were 52.3 mg/L Ca, 67.7 mg/L Al, 48.8 mg/L Si, and 11.7 mg/L Mg. The hydration products of hardened cements were investigated by X-ray diffraction, scanning electron microscopy, and Fourier transform infrared, showing the accelerated setting time was due to the formation of honeycomb-like calcium silicate hydrate gel. The novel MTA could be a promising material for dental applications.

15 citations

Journal ArticleDOI
TL;DR: In this article, two powder preparation routes were explored: aluminium and calcium or strontium nitrate hydrates were added to alumina zirconia powders and in the second only calcium or Strontium Nitrate hyDRates were used.
Abstract: This paper proposes new preparation methods for alumina–tetragonal zirconia–Ca or Sr hexaluminate composites. Two powder preparation routes were explored. In the first, aluminium and calcium or strontium nitrate hydrates were added to alumina zirconia powders and in the second only calcium or strontium nitrate hydrates were used. Powders produced by the second route are to be preferred since reinforcements do not inhibit the composite sintering process.

15 citations


Network Information
Related Topics (5)
Sintering
76K papers, 892.1K citations
77% related
Microstructure
148.6K papers, 2.2M citations
75% related
Thermogravimetric analysis
37.2K papers, 862.1K citations
75% related
Alloy
171.8K papers, 1.7M citations
73% related
Corrosion
152.8K papers, 1.9M citations
73% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20221
202112
202010
201914
201819
201715