Application of internal curing for mixtures containing high volumes of fly ash
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Date
2012
Journal Title
Journal ISSN
Volume Title
Publisher
ELSEVIER SCI LTD
Abstract
This paper focuses on testing performed on mixtures that would be consistent with the mortar portion of a concrete bridge deck mixture for many state departments of transportation. In this work a relatively large percentage of cement (40%, 60%, or 80% by volume) is replaced with Class C fly ash. To overcome concerns associated with slow set and early-age strength development that are often expressed with the high volume fly ash mixtures (HVFA), the water-to-cementitious materials ratio (w/cm) by mass has been reduced from a conventional value of 0.42 to 0.30. To overcome potential complications that the low w/cm may cause in terms of self-desiccation, internal curing (IC) with prewetted lightweight aggregate was used to reduce shrinkage and increase hydration. By adopting this approach (lowering the w/c and using IC) IC HVFA mixtures show additional benefits that should permit their broader application. (c) 2012 Elsevier Ltd. All rights reserved.
Description
Keywords
Autogenous shrinkage, Cracking, High volume fly ash, Hydration, Internal curing, Restrained shrinkage, SHRINKAGE CRACKING, CONCRETE, DURABILITY