Is Lightweight Concrete All Wet?
Lightweight concrete is occasionally
thought to be the primary culprit
in moisture-related failures...Learn more!
Internal Curing for Concrete
“The practical solution to concrete shrinkage”.
TXI ES&C’s intraCure is the internal curing process used for portland cement based products to reduce early age cracking utilizing TXI’s rotary kiln lightweight aggregate with a minimum absorption of 18%.
In the past, curing concrete was a process done using water from the outside in. But today, ES&C is used as a substitute for normal-weight aggregates to provide a source of moisture for internal curing that promotes more complete hydration of various cementitious materials.
Due to the inherently low permeability of the surrounding environment, internal curing is particularly beneficial in concrete with a low-water-cementitious material ratio (w/cm) where external curing has little effect on hydration in the internal portion of the concrete. With an emphasis on durability, and with the trend to high performance concrete, internal curing is needed to reduce both autogenous shrinkage and cracking.
With regard to high performance concrete, it is difficult to provide curing water from the top surface at the rate that is required to satisfy the ongoing chemical shrinkage, as the capillary passageways often become clogged with the products of cement hydration. However, ES&C typically contains between 18% and 25% water by weight. This water is released from the lightweight aggregate pores as the concrete cures and replaces a portion of the original mixture water that is consumed by the hydration process.
One example of TXI’s successful blend of an intermediate size lightweight aggregate into concrete mixture took place for use in residential applications in which a 3/8 in. to No. 8 (9.5) to 2.36mm ES&C aggregate met all the requirements of ASTM C 330 and replaced a portion of both the coarse and fine aggregates. This aggregate size not only enhanced the hydration of the cementitious materials, but also complemented the total aggregate grading in the concrete.
eTools
Mobile Internal Curing Calculator
Case Studies
Extending Service Life of High Performance Concrete Bridge Decks with Internal Curing
Internal Curing - Using Expanded Shale, Clay and Slate Lightweight Aggregate
Internal Curing: An Unconventional Idea...Within a Conventional Business
Benefits of Internal Curing on Service Life and Life-Cycle Cost of High Performance Concrete Bridge Decks - A Case Study
The Use of Lightweight Fines for the Internal Curing of Concrete
Featured Projects
SH 121 - Collin County, Texas
Internally Cured Concrete Used in Denver Water’s Lone Tree Tank No. 2
TXI Hydromax Internal Curing Concrete Mix used on IH-30 Bridge
Bremerton Floating Breakwater
Union Pacific Inter-modal Facility
White Papers
Internal Curing of Concrete Paving: Laboratory and Field Experience
Internal Curing - Questions and Answers
Internal Curing: A 2010 State-of-the-Art Review
Cracking Tendency of Lightweight Concrete
Internal Curing: Constructing more Robust Concrete
Early-Age Cracking Tendency and Ultimate Degree of Hydration of Internally Cured Concrete
Additional Resources
Internal Curing Presentation on Improved Service Life - Jason Weiss, Purdue University
Internal Curing: Helping Concrete Realize Its Maximum Potential
Concrete Crack Damage – A Thing of the Past?
How I Tried to Prevent The T-REX Bridges From Cracking
Internal Curing of Concrete - Frequently Asked Questions
ASTM Standard Specification for Lightweight Aggregate for Internal Curing of Concrete - C1761/C1761M - 12
Indiana Using Internally Cured Concrete to Increase Bridge Life Span
