NISCAIR Online Periodicals Repository

NISCAIR ONLINE PERIODICALS REPOSITORY (NOPR)  >
NISCAIR PUBLICATIONS >
Research Journals >
Indian Journal of Chemical Technology (IJCT) >
IJCT Vol.14 [2007] >
IJCT Vol.14(3) [May 2007] >


Title: Hydration of calcined bentonite Portland blended cement pastes
Authors: Darweesh, H H M
Nagieb, Z A
Keywords: Blended cement
Hydration
Free lime
Combined water
Porosity
Density
Issue Date: May-2007
Publisher: CSIR
IPC CodeC04B7/02
Abstract: The formation of free lime (CH) during the hydration of Ordinary Portland Cement (OPC) decreases the durability of cement structures. The pozzolanic properties of calcined clays allow to avoid this drawback. So, the reaction kinetics of the OPC/calcined bentonite blended cement pastes were investigated. The results show that the water of consistency as well as setting time increase gradually with the addition of calcined bentonite at the expense of OPC. The combined water content also increases with the substitution of OPC by calcined bentonite up to 9-12 mass% and then decreases. The free lime content increases up to 3-7 days and then decreases. Also, the bulk density increases slightly, while the apparent porosity decreases. The compressive strength increases sharply up to 28 days, and slightly increases up to 90 days due to the pozzolanic reactions of calcined bentonite. The cement pastes containing 12 or 15 mass% bentonite were adversely affected at all curing ages of hydration. The SEM micrographs indicate that the hydration products of the OPC/calcined bentonite cement pastes are the same as those of the pure OPC pastes, but with different ratios, crystals and morphologies.
Page(s): 301-307
ISSN: 0971–457X
Source:IJCT Vol.14(3) [May 2007]

Files in This Item:

File Description SizeFormat
IJCT 14(3) (2007) 301-307.pdf563.05 kBAdobe PDFView/Open
 Current Page Visits: 758 
Recommend this item

 

National Knowledge Resources Consortium |  NISCAIR Website |  Contact us |  Feedback

Disclaimer: NISCAIR assumes no responsibility for the statements and opinions advanced by contributors. The editorial staff in its work of examining papers received for publication is helped, in an honorary capacity, by many distinguished engineers and scientists.

CC License Except where otherwise noted, the Articles on this site are licensed under Creative Commons License: CC Attribution-Noncommercial-No Derivative Works 2.5 India

Copyright © 2012 The Council of Scientific and Industrial Research, New Delhi. All rights reserved.

Powered by DSpace Copyright © 2002-2007 MIT and Hewlett-Packard | Compliant to OAI-PMH V 2.0

Home Page Total Visits: 624597 since 06-Feb-2009  Last updated on 13-Nov-2014Webmaster: nopr@niscair.res.in