ASTM at work on proposed lightweight aggregates standard

Words: Barbara Ambach/Public/News/20110926130000-1.jpg" width="600" height="338" border="0" alt="ASTM is developing a proposed standard, Specification for Lightweight Aggregate for Internal Curing of Concrete." />
ASTM is developing a proposed standard, Specification for Lightweight Aggregate for Internal Curing of Concrete.
While the use of internally cured concrete in construction is not new, there is now better understanding of the internal curing process and why IC using pre-wetted lightweight aggregate increases concrete durability and service life in an economical and practical way. However, there is not currently a standard for lightweight aggregates for internal curing.

ASTM International Committee C09 on Concrete and Concrete Aggregates is now developing such a proposed standard, ASTM WK34078, Specification for Lightweight Aggregate for Internal Curing of Concrete. The proposed standard is under the jurisdiction of Subcommittee C09.21 on Lightweight Aggregates and Concrete.

“Concrete, especially high performance concrete, is designed to limit the permeability and reduce chloride ingress,” says John Ries, technical director, Expanded Shale, Clay and Slate Institute, and a C09 member. “Unfortunately, these properties also limit the ability of externally applied curing water to reach the interior of the concrete. The main objective of internal curing is to provide a source of additional water to maintain saturation of the cementitious paste and avoid its self-desiccation.”

Ries says that internal curing can significantly increase the service life of concrete by increasing cement hydration, providing more complete reaction of supplementary cementitious materials and reducing chemical and drying shrinkage.

According to Ries, the proposed new standard will be useful in a variety of civil engineering projects, including roads, driveways, bridges, parking lots, water and sewage treatment tanks, and others. Users of the proposed standard will include the U.S. Federal Highway Administration, state departments of transportation, architects, and environmental, structural and civil engineers.

Interested parties are invited to join in the standards developing activities of C09. ASTM International welcomes and encourages participation in the development of its standards. For more information on becoming an ASTM member, visit www.astm.org/join.
About: Featured
Masonry Mortar: The Right Type for the Job
May 2025

When it comes to masonry construction, mortar is much more than “glue” that holds everything together — it’s a critical component of wall performance, longevity, and aesthetics. It can “make it or break it”. Whether you’re laying a foundation CMU wall or

MASONRY STRONG Podcast, Episode 20 Recap: Mark Kemp, Superior Masonry
May 2025

On this episode of the MASONRY STRONG Podcast, Mark Kemp joins the set to talk about his esteemed career in masonry, how his passion stayed strong throughout the years, and how retirement has been treating him.

How It’s Made: Clay Thin Brick
May 2025

Clay thin brick is a versatile alternative to traditional full brick. It comes in numerous colors and styles and offers something for every design preference. Thanks to the lighter weight, it is designed to reach spaces full brick cannot. From floors to c

Bonding with Masonry 2025: Q1
May 2025

This issue’s questions come from an Architect and a Mason Contractor. What questions do you have? Send them to info@masonrymagazine.com, attention Technical Talk. Q. An Architect asks how to create a narrow masonry pier between openings. Is there a min