Activation of Fly Ash–Lime Reactions: Kinetic Approach

Rao, Sudhakar and Asha, K (2012) Activation of Fly Ash–Lime Reactions: Kinetic Approach. In: JOURNAL OF MATERIALS IN CIVIL ENGINEERING, 24 (8). p. 1110.

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Abstract

Lime–fly ash reactions play a key role in improving the mechanical strength and tailoring the permeability characteristics of compacted fly ash. Activation of fly ash–lime pozzolanic reactions should accelerate the rate of strength development and possibly mobilize higher compressive strengths, facilitating improved engineering performance of fly ash amended materials. This paper makes an assessment of activation of lime–fly ash reactions by curing compacted fly ash–lime specimens at ambient (25°C) and at elevated temperature (80°C). The kinetics of fly ash–lime reactions are examined by monitoring the reacted lime as a function of curing period and temperature. The influence of variations in fly ash/lime content and dry density on the compressive strength developed by specimens at both temperatures is evaluated. The thermodynamic parameters for the fly ash–lime reactions have also been examined. Experimental results showed that curing at 80°C for 24 h accelerated fly ash–lime reactions such that it caused the steam cured (SC) specimens to evelop 1.21–2.44 fold larger strengths than room-temperature cured (RTC) specimens cured at 25°C for 28 days. Analysis of thermodynamic parameters indicated that the fly ash–lime reactions are thermodynamically favored at fly ash contents of 50–70% and lime additions of 16–20%, and the reactions are endothermic in nature. DOI: 10.1061/(ASCE)MT.1943-5533.0000482. © 2012 American Society of Civil Engineers.

Item Type:	Journal Article
Publication:	JOURNAL OF MATERIALS IN CIVIL ENGINEERING
Publisher:	JOURNAL OF MATERIALS IN CIVIL ENGINEERING © ASCE
Additional Information:	Copyright for this article belongs to the ASCE
Department/Centre:	Division of Mechanical Sciences > Centre for Sustainable Technologies (formerly ASTRA) Division of Mechanical Sciences > Civil Engineering
Date Deposited:	24 Jun 2014 09:25
Last Modified:	24 Jun 2014 09:25
URI:	http://eprints.iisc.ac.in/id/eprint/49343

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