Results 221 to 230 of about 12,946 (261)

Evaluation of the activity of pozzolanic materials

Journal of Applied Chemistry and Biotechnology, 1974
AbstractCompressive strength and solubilisation tests were carried out to evaluate the pozzolanic activity of some natural and artificial materials. Strength tests were performed on mortar made with cements composed of 61% Portland cement clinker, 35% pozzolanic material and 4% gypsum.
Kaissar M. Hanna, Aly Afify
openaire   +1 more source

Thermal treatment and pozzolanic activity of sepiolite

Applied Clay Science, 1996
Abstract Samples of standard sepiolite were calcined at 370, 570 and 830°C corresponding to the various stages of thermal reaction detected by DTA and TG. Both the raw and calcined samples, before and after being mixed with Ca(OH) 2 in the presence of simulated cement pore solution, were studied with XRD, SEM, EPMA and chemical solubility.
He, Changling, Makovicky, Emil, Osbæck, B.   +2 more
openaire   +1 more source

Pozzolanic Activity of Calcined Red Mud

"SP-132: Fly Ash, Silica Fume, Slag, and Natural Pozzolans and Natural Pozzolans in Concrete - Proceedings Fourth Interna", 1992
In order to investigate the possibility of using red mud by-product from the aluminum industry) as a pozzolan in the cement and concrete industries, tests were carried out to examine the pozzolanic properties of calcined red mud. It was found that the red mud had the maximum reactivity when calcined at 600 deg C, because on hydration the lime content ...
openaire   +1 more source

Monitoring pozzolanic activity by direct activation with calcium hydroxide

Construction and Building Materials, 1996
Abstract In this paper the change in conductivity of pozzolan/CH mixtures, at ambient temperatures, is monitored for periods extending over two days. Such a method allows the chemical activity within the mixture to be followed and it is shown that a number of features/parameters can be identified which are related to the pozzolanic reactivity of the ...
W.J. McCarter, D. Tran
openaire   +1 more source

Pozzolanic behavior of thermally activated kaolin

"SP-132: Fly Ash, Silica Fume, Slag, and Natural Pozzolans and Natural Pozzolans in Concrete - Proceedings Fourth Interna", 1992
In this study different clays were tested with various granular sizes and calcination parameters. The pozzolanic properties were investigated using metakaolin-lime mixtures by the evaluation of both the mechanical strength and combined lime. The mineralogical composition, particle size distribution and degree of amorphousness were the main factors ...
openaire   +1 more source

Pozzolanic activity of various siliceous materials

Cement and Concrete Research, 2006
Abstract The accelerated pozzolanic activity of various siliceous materials, like silica fume, fly ash (as received and fine ground), quartz, precipitated silica, metakaolin and rice husk ash (RHA; various fineness and carbon content), has been determined.
openaire   +1 more source

Pozzolanic activity of metakaolin under microwave treatment

Cement and Concrete Research, 1995
Abstract Calcium hydroxide produced by cement hydration decreases durability of concrete placed in aggressive solutions and fibrereinforced cement composites. Pozzolanic properties of metakaolin allow to avoid this drawback. In the present study the effect of a microwave curing on lime consumption in metakaolin blended cements was investigated.
M. Oriol, J. Pera
openaire   +1 more source

Pozzolanic activity of palm bunch wastes

Materials and Structures, 1989
The paper reports an investigation of the ash from the burnt stalks of oil palm bunches as a suspected agricultural waste with pozzolanic activity. Chemical analysis confirmed the presence of the major elements silica, alumina, potassium and a comparatively low content of calcium, all of which are necessary for pozzolanic activity.
openaire   +1 more source

Inexpensive intumescent alkali-activated natural pozzolan pastes

Journal of the European Ceramic Society, 2015
Abstract Perlite, a natural pozzolan, was activated with NaOH to prepare alkali-activated (AA) intumescent pastes. After curing at 100 °C for 3–24 h, the solidified pastes had medium strengths, up to 40 MPa, and low densities, ∼1500–2000 kg/m 3 , compared to Portland cement pastes.
openaire   +1 more source

Effect of Mechanical Activation on the Pozzolanic Activity of Muscovite

Clays and Clay Minerals, 2019
AbstractIn order to provide a theoretical foundation for the utilization of tailings as supplementary cementitious materials, the pozzolanic activity of muscovite—a typical mineral phase in tailings—before and after mechanical activation was investigated.
Geng Yao, Haoyu Zang, Junxiang Wang, Peng Wu, Jun Qiu, Xianjun Lyu   +5 more
openaire   +1 more source