A Multi-scale approach to characterization of volcanic natural pozzolans/

Sassani, Alireza
Three types of volcanic rocks, namely perlite, a zeolite-rich volcanic tuff and a feldspar-rich volcanic tuff were selected to represent the general group of Volcanic Natural Pozzolans (VNPs). The target group was those volcanic natural pozzolans which intrinsically possess pozzolanic properties, i.e. do not require heat-treatment to obtain pozzolanic reactivity. X-ray Fluorescence (XRF), Powder X-Ray Diffraction (XRD), Blaine air permeability test, Laser diffraction, thermogravimetry (TGA), solid-state 29Si nuclear magnetic resonance spectroscopy (NMR) and solidstate 27Al NMR techniques were utilized to characterize the unhydrated powder of the selected pozzolans. For each of the three selected VNPs the engineering performance of the respective 50 (wt%) VNP-50 (wt%) PC based system were evaluated. Mortar samples were studied for strength development and expansion due to Alkali-Silica reaction (ASR); while paste samples were studied by Isothermal Calorimetry method in order to monitor the heat evolution during the hydration. Pastes were then studied by the use of XRD, 29Si NMR, and 27Al NMR techniques vi so as to investigate the micro- and nano-structure of the hydration products of 50 (wt%)NP-50 (wt%)PC systems. The performance of the selected pozzolans with respect to pozzolanic activity and ASR expansion were almost similar; they all exhibited acceptable pozzolanic performance and ability to suppress ASR expansion. However, the pozzolans had different sources of pozzolanic reactivity, i.e. their pozzolanic property originate from different phases and/or is associated with different mechanisms. The C-S-H phases in the NP-blended pastes possessed longer silicate chains than the control samples. Aluminum incorporation into C-S-H structure was investigated and various Aluminum species were detected.


Bozkurt, Erdin; WINCHESTER, JA (Wiley, 1993-01-01)
The Menderes Massif, in western Anatolia, has been described as a lithological succession comprising a basal 'Precambrian gneissic core of sedimentary origin' overlain in sequence by 'Palaeozoic schist' and 'Mesozoic-Cenozoic marble' forming the envelope. The boundary between core and schist envelope was interpreted as a major unconformity, the 'Supra-Pan-African unconformity'. By contrast, our field observations and geochemical data show that around the southern side of Besparmak Mountain, north of Selimiy...
Reconstructing the geometry of central Anatolia during the late Cretaceous: Large-scale Cenozoic rotations and deformation between the Pontides and Taurides
Lefebvre, Come; Meijers, Maud J. M.; Kaymakcı, Nuretdin; Peynircioglu, Ahmet; Langereis, Cor G.; van Hinsbergen, Douwe J. J. (Elsevier BV, 2013-03-15)
The Central Anatolian Crystalline Complex (CACC) exposes metamorphic, ophiolitic and igneous rocks that were formed and deformed during closure of the Neotethyan ocean. The CACC is located in central Turkey, between the Pontides in the north and the Taurides in the south, separated by major fault zones. Composite plutons intruded the meta-sedimentary and ophiolitic units between similar to 95 and 75 Ma, and form linear magmatic belts (similar to 100 km long) along the western and northern margins of the CAC...
An Approach to the Central Anatolian (Avanos) Late Mesozoic Magmatism: Petrology of Cogenetic Granitic and Volcanic Rocks.
Toksoy Köksal, Fatma; Köksal, Serhat (null; 2008-03-28)
The petrology of the granitic and volcanic rocks cropping out in Avanos (Nevşehir) area sheds light on the nature of magmatism in central Anatolia. In the region while granitoids intrude the Precambrian-Paleozoic-Mesozoic metamorphic basement rocks, volcanic rocks are found as dykes cutting granitoids and blocks in Late Cretaceous (?)- Early Paleocene olistostromal unit (Göncüoğlu et al., 1997; Köksal et al., 2001). The felsic intrusive rocks in the Avanos area are quartz-syenite and alkali-feldspar quartz...
A geochemical approach to Neogene-Quaternary volcanic activity of western Anatolia: An example of episodic bimodal volcanism within the Selendi Basin, Turkey
Ersoy, Y.; Helvaci, C.; Sozbilir, H.; ERKÜL, FUAT; Bozkurt, Erdin (2008-09-30)
New radiometric age and geochemical data are presented from the late Cenozoic volcanic activity in the Selendi Basin of western Anatolia. Stratigraphical and age data show that the volcanism occurred in four distinct stages from the early Miocene to Quaternary. The first early Miocene stage includes two volcanic units with contrasting compositions: the Egreltidag volcanic unit and the Kuzayir lamproite. These volcanic units interfinger with the sedimentary rocks of the early Miocene Hacibekir Group. The Egr...
A reaction-transport-mechanical approach to modeling the interrelationships among gas generation, overpressuring, and fracturing: Implications for the Upper Cretaceous natural gas reservoirs of the Piceance basin, Colorado
Payne, DF; Tuncay, Kağan; Park, A; Comer, JB; Ortoleva, P (2000-04-01)
Predicting reservoir characteristics in tight-gas sandstone reservoirs, such as those of the Upper Cretaceous units of the Piceance basin, is difficult due to the interactions of multiple processes acting on sediments during basin development. To better understand the dynamics of these systems, a forward numerical model, which accounts for compaction, fracturing, hydrocarbon generation, and multiphase flow (BasinRTM) is used in a one-dimensional simulation of the U.S. Department of Energy's Multiwell Experi...
Citation Formats
A. Sassani, “A Multi-scale approach to characterization of volcanic natural pozzolans/,” M.S. - Master of Science, Middle East Technical University, 2014.