ABOUT THE INTERNATIONAL CONCRETE ABSTRACTS PORTAL

  • The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal

  


Title: Lightweight Aggregate as Internal Curing Agent to Limit Concrete Shrinkage

Author(s): JoAnn Browning, David Darwin, Diane Reynolds, and Benjamin Pendergrass

Publication: Materials Journal

Volume: 108

Issue: 6

Appears on pages(s): 638-644

Keywords: Bridge decks; cracking; curing; drying shrinkage; lightweight aggregate; slag cement; vacuum saturation.

DOI: 10.14359/51683467

Date: 11/1/2011

Abstract:
The effectiveness of prewetted, vacuum saturated (PVS) lightweight aggregate (LWA) as an internal curing agent to reduce concrete shrinkage is evaluated for curing periods of 7 and 14 days. Normalweight aggregate is replaced by LWA at volume replacement levels ranging from 8.9 to 13.8%. Some mixtures contain a partial replacement of portland cement with slag cement while maintaining the paste content at approximately 24.1% of concrete volume. Comparisons are made with mixtures containing low-absorption granite and high-absorption limestone normalweight coarse aggregates. At the replacement levels used in this study, PVS LWA results in a small reduction in concrete density, no appreciable effect on concrete compressive strength, and a substantial decrease in concrete shrinkage for drying periods up to 365 days. Increasing the curing period from 7 to 14 days reduces concrete shrinkage. Thirty and 60% volume replacements of portland cement by slag cement result in reduced shrinkage when used with a porous LWA or normalweight aggregate. After 30 and 365 days of drying, all mixtures with LWA exhibited less shrinkage than the mixtures with either low- or high-absorption normalweight aggregates.


ALSO AVAILABLE IN:

Electronic Materials Journal