Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Internal Curing: A 2010 State-of-the-Art Review

Published

Author(s)

Dale P. Bentz, Jason Weiss

Abstract

The American Concrete Institute in 2010 defined internal curing as supplying water throughout a freshly placed cementitious mixture using reservoirs, via pre-wetted lightweight aggregates, that readily release water as needed for hydration or to replace moisture lost through evaporation or self-desiccation (American Concrete Institute, 2010). While internal curing has been inadvertently included in many lightweight concretes produced within the past 100 years, it is only within the first decade of the 21st century that this technology has been intentionally incorporated into concrete mixtures at the proportioning stage, using a variety of materials including pre-wetted lightweight aggregates, pre-wetted crushed returned concrete fines, superabsorbent polymers, and pre-wetted wood fibers. This report provides a state-of-the-art review of the subject of internal curing, first addressing its history and theory, and then proceeding to summarize published guidance on implementing internal curing in practice and published research on its influence on the performance properties of concrete. The ongoing exploration of extensions of the internal curing concept that employ the internal reservoirs to contain materials other than water are reviewed. Finally, the critical issue of sustainability is addressed. An extensive internal curing bibliography that is also available over the Internet is included in an appendix. The report is mainly focused on the utilization of pre-wetted lightweight aggregates as the internal reservoirs due to this being the current established practice within the U.S.
Citation
NIST Interagency/Internal Report (NISTIR) - 7765
Report Number
7765

Keywords

concrete, hydration, internal curing, lightweight aggregate, self-desiccation.

Citation

Bentz, D. and Weiss, J. (2011), Internal Curing: A 2010 State-of-the-Art Review, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.IR.7765 (Accessed July 26, 2021)
Created February 9, 2011, Updated November 10, 2018