Results 171 to 180 of about 4,199 (222)

Pozzolans and the Pozzolanic Reaction

1990
The most often used mineral admixture in the modern concrete industry is the pozzolan. A pozzolan, and there are many of them, is defined as “siliceous or siliceous and aluminous materials which in themselves possess little or no cementitious value but will, in finely divided form and in the presence of moisture, chemically react with calcium hydroxide
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Evaluation of pozzolanic activity of natural and artificial pozzolans by thermal analysis

Thermochimica Acta, 2004
Abstract In this research, the pozzolanic activity of natural and artificial pozzolan used for preparation of restoration mortars was evaluated. For this purpose, several pastes were prepared, by mixing two artificial pozzolans and a natural one with commercial hydrated lime, in different ratios. The pastes were cured in standard conditions (RH = 98%,
Antonia Moropoulou, Asterios Bakolas, Eleni Aggelakopoulou   +2 more
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Pozzolanic activity tests as a measure of pozzolans' performance. Part 2

Magazine of Concrete Research, 2007
Part 1 of the current paper demonstrated the lack of agreement between the results obtained from different standard pozzolanic activity tests. This can be explained by the significant differences observed in the recommended test procedures that, in some cases, allow variations in parameters which have a remarkable influence on the pozzolanic reaction.
G. P. Gava, L. R. Prudêncio
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Effects of pozzolanic and non-pozzolanic nanomaterials on cement-based materials

Construction and Building Materials, 2019
Abstract Although it has been verified that nanomaterials can improve the properties of cement-based materials, the research on the characteristics and mechanism of different types of nanomaterials is still inadequate. Two typical types of nanomaterials, nano-SiO2 (pozzolanic material) and nano-TiO2 (non-pozzolanic material), are utilized in this ...
Huigang Xiao, Fengling Zhang, Rui Liu, Rongling Zhang, Zhiguo Liu, Hongxia Liu   +5 more
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Pozzolanic activity of natural pozzolan–lime pastes and physicomechanical characteristics

Journal of Thermal Analysis and Calorimetry, 2018
In order to evaluate the pozzolanic activity of a natural pozzolan (NP) of rhyolitic composition, several pastes were prepared by mixing the pozzolan with hydrated lime, in different ratios. The pastes were stored in standard conditions (RH = 99 ± 1%, T = 25 ± 1 °C) and evaluated using thermal analysis (TG-DTA), X-ray diffraction, compressive strength ...
Asterios Bakolas, Eleni Aggelakopoulou
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POZZOLAN AND CEMENTS WITH POZZOLAN

2015
Yapı mühendisliğinin temel malzemelerinden olan çimento, yapının dayanımı ve maliyeti bakımından önemli bir yere sahiptir. İnşaat sektöründeki gelişmeye paralel olarak çimento tüketimi de artmaktadır. Çimento üreticileri açısından, yeni yeni kaynaklar bulunarak üretimin minimum maliyetle yapılması ve talebin karşılanması, yapımcı ve kontrolluk ...
KAPLAN, Hasan, BİNİCİ, Hanifi
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Trinidad porcellanite as a pozzolan

Matériaux et Constructions, 1975
“Fuel consumer” countries could save fuel and also make better use of their own resources by using pozzolans to replace part of their Portland cement requirements. A recent BRE study of porcellanite from Trinidad provides an example of the type of work needed to assess such materials.
W. Gutt, M. E. Gaze
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Pozzolan

1969
Abstract Pozzolans are finely divided siliceous or siliceous and aluminous materials that are by themselves of little or no cementitious value but that react with calcium hydroxide in the presence of water at ordinary temperatures to form cementitious compounds.
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Pozzolanic activation of metakaolin

Advances in Cement Research, 1992
Metakaolin may be calcined without grinding and suitably activated by Ca(OH)2, Na2SO4, CaSO4 (beta anhydrite) and/or NaOH. The best strengths, 50 MPa from mortar cubes at 18 months, were obtained using Ca(OH)2 and CaSO4 activators. The handling and set properties are similar to those of Portland cement; aluminous C-S-H gel is the best binder.
P. S. De Silva, F. P. Glasser
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Influence of the fineness of pozzolan on the strength of lime natural-pozzolan cement pastes

Cement and Concrete Research, 1994
Abstract The fineness of a cement is an important factor affecting the rate of strength development. This paper examines the importance of the fineness of natural pozzolans to the strength development of lime-pozzolan cements (LPCs). A natural pozzolan from Bolivia, which is typical of natural pozzolans found in South and Central America, was ground ...
Robert L. Day, Caijun Shi
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