Results 131 to 140 of about 2,024 (169)

Grinding and pozzolanic reactivity of quartz powders

Powder Technology, 1999
Abstract Cement-based materials are in wide use — partly in the belief that their reactivity is due to their glassy nature. The question we wish to investigate is: how specific is the link between the pozzolanic reaction and glassy materials? In order to answer it, we take the case of quartz, a material often used in cement-based matrices, reputed to
J.C Benezet, A Benhassaine
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Effects of the pozzolanic reactivity of nanoSiO2 on cement-based materials

Cement and Concrete Composites, 2015
Abstract The aim of this work is to understand the characteristics of the pozzolanic reactivity of nanoSiO2 from studies of its pozzolanic reaction kinetics, morphology and structure of the hydrates and the influences of these features on the properties of cement-based materials, so as to explore a more targeted way of using nanoSiO2 in cement or ...
Pengkun Hou, Surendra Shāh, Jueshi Qian   +2 more
exaly   +2 more sources

Evaluation of the Metakaolin Pozzolanic Reactivity in Cement Pastes

Materials Science Forum, 2008
The pozzolanic reactivity of a commercial metakaolin (MK) manufactured in Brazil, was evaluated in pastes prepared with a type II Portland cement, when used in cement substitution degrees from 10 to 40 mass % by thermal analysis techniques. The reactivity during the early stages of hydration was studied in real time from Non-Conventional Differential ...
Armando Lucas Cherem da Cunha, Jardel Pereira Gonçalves, Frank K. Cartledge, Romildo Dias Toledo Filho, Jo Dweck   +4 more
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Comparison of different methods for enhancing reactivity of pozzolans

Cement and Concrete Research, 2001
Abstract This paper compares three methods for the activation of pozzolanic reactivity of a natural pozzolan: (1) prolonged grinding of natural pozzolans (mechanical method), (2) elevated temperature curing of cement pastes containing a pozzolan (thermal method), and (3) use of chemical activators such as Na2SO4 and CaCl2 (chemical method).
Caijun Shi, Robert L Day
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An overview on the activation of reactivity of natural pozzolans

Canadian Journal of Civil Engineering, 2001
Natural pozzolan is one of the oldest construction materials. Lime-pozzolan cements have been used for several thousands of years and have an excellent reputation for their durability. Pozzolans are being widely used as a cement replacement in Portland cement concrete.
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Spectrophotometric method for estimating the reactivity of pozzolanic materials

Advances in Cement Research, 1988
Synopsis A spectrophotometric method is described for estimating the reactivity of pozzolanic materials. The method consists of boiling the pozzolana in 0·5 N NaOH solution for 3 min and estimating the alkali-soluble silica by spectrophotometry.
M. S. Surana, S. N. Josh
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Reactivity of lime Activated Pozzolans

SP-202: Third Canmet/ACI International Symposium: Sustainable Development of Cement and Concrete, 2001
This paper utilizes electrical methods to follow the early hydration characteristics of a range of materials activated with calcium hydroxide at room temperature (20 degrees C). The electrical response is measured in terms of the in-phase (i.e. resistance) and quadrature (i.e. capacitance) components of the sample admittance.
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Pozzolanic reactivity of silico-aluminous fly ash

Particuology, 2008
Abstract For some years it has been possible to control the particle size of fly ashes, by-products of thermal power stations. Incorporating these very fine particles (obtained by grinding and/or pneumatic selection) improves the physical–mechanical characteristics of mortars and concretes.
Pierre Adamiec, Jean-Charles Benezet, Ali Benhassaine   +2 more
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Estimating reactivity of pozzolanic materials by a spectrophotometric method

Advances in Cement Research, 1990
Following earlier work on estimating the reactivity of pozzolanic materials, three classes of pozzolanas have been further investigated, to ascertain whether or not a more linear calibration curve is possible. A better linear correlation exists when separate calibration curves between absorbance and lime-pozzolana mortar strength values for different ...
M. S. Surana, S. N. Joshi
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Influence of Mineral Impurities on the Pozzolanic Reactivity of Metakoalin

2015
In nature, kaolinite deposits are rarely completely pure. In addition to the mineral kaolinite other clay minerals such as smectites and illites, but also non-clay minerals such as quartz, feldspar, calcite and muscovite are often present in the clay.
Sofie Hollanders, Özlem Cizer, Jan Elsen   +2 more
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