ASTM Proposed Standard: Recycling of Returned Ready-Mixed Concrete

A proposed new ASTM International standard will cover the process, verification and record keeping procedures for recycling returned fresh concrete. The proposed standard, ASTM WK39876, Specification for Returned Fresh Concrete for Use in a New Batch of Ready-Mixed Concrete, is being developed by Subcommittee C09.40 on Ready-Mixed Concrete, part of ASTM International Committee C09 on Concrete and Concrete Aggregates.
 
A significant amount of concrete is returned to manufacturing plants, which can result in wasted material, the need for disposal and unnecessary environmental impact. These issues can, however, be minimized since some of the returned concrete is suitable for reuse and can be incorporated into new batches. A proposed ASTM International standard will ensure that returned fresh concrete mixed with new concrete has known and verifiable characteristics.

“Concrete is the most widely used building material in the world,” says Eric Koehler, VP, Verifi LLC, and chairman of the task group developing ASTM WK39876. “The proposed standard will help ready mixed concrete manufacturers reduce waste material and disposal requirements. Purchasers and specifiers of concrete can obtain concrete with greater recycled content while ensuring the concrete is of high quality.”

Koehler notes that technology available to facilitate the reuse of returned fresh concrete includes hydration stabilizing admixtures that can be used to extend the setting time of concrete and ensure that concrete can be used in a new batch. In addition, truck-mounted equipment can be used to measure, manage and record concrete slump, water content, temperature and load size throughout the delivery cycle to reduce the need for manual testing.

Subcommittee C09.40 welcomes all interested parties, particularly those with experience in using returned fresh concrete, to contribute to the ongoing development of ASTM WK39876.

ASTM International welcomes participation in the development of its standards. For more information on becoming an ASTM member, visit www.astm.org/JOIN.

Thomson Receives ASTM International Walter C. Voss Award

Margaret Thomson, Ph.D., new business development technical director at Lhoist North America in Fort Worth, Texas, has received the Walter C. Voss Award from ASTM International. The Voss Award is presented annually to an engineer or scientist who has made notable contributions in the field of building technology. 

Thomson was honored by ASTM for her numerous contributions to the development of standards and specifications for the use of lime in construction applications, especially in the area of repair and maintenance of historic mortars.

A member of ASTM International since 1996, Thomson is vice chairman of Committee C07 on Lime and chairman of Subcommittee C07.06 on Physical Tests. She also serves as a member at large on the executive subcommittee of Committee C12 on Mortars and Grout for Unity Masonry and received the Award of Merit, ASTM's highest organizational recognition for individual contributions to ASTM standards activities, from the committee in 2011. She is also a member of ASTM Committees C01 on Cement, C15 on Manufactured Masonry Units and E60 on Sustainability.

Thomson joined Lhoist North America (formerly Chemical Lime Co.) as technical manager of Chemstar Type S Hydrated Lime in 1996. She was promoted to technical director, Western Sales Division, in 2009, and received her current title in 2011. Before Lhoist, she was a research scientist focusing on performance of lime-based mortar for masonry at the National Research Council Canada's Institute for Research in Construction. A graduate of University of Western Ontario, London, Ontario, where she received a B.Sc. with honors in geology and a Ph.D. in geology, Thomson is also a member of the Masonry Society.

Papers Invited for ASTM International Symposium on Masonry

Papers are invited for the symposium Masonry 2014, to be held June 24, 2014, at the Sheraton Toronto in Toronto, Ontario, Canada. The symposium is being co-sponsored by ASTM International Committees C01 on Cement, C07 on Lime, C12 on Mortars and Grouts for Unit Masonry, and C15 on Manufactured Masonry Units, and will be held in conjunction with the standards development meetings of the committees.

The objective of Masonry 2014 is to gather and disseminate the latest information on all aspects of the innovations in masonry materials, design, specification, construction, maintenance and rehabilitation. It will emphasize the application of ASTM standards to those areas, and their coordination with building codes, project specifications and international standards.

Papers are sought on the following topics: anchors and ties; building codes; cements (portland, blended, hydraulic, masonry, plastic); flexural bond strength; limes (hydrated, hydraulic, putty); masonry inspection; mortars; plastic/stucco; structural masonry; sustainability; veneers; water penetration and more. See the full list of topics at www.astm.org/C07callforpapers.

To participate in the symposium, presenters/authors must submit a 250-300 word preliminary abstract at www.astm.org/C07callforpapers by April 4, 2013. The abstract must include a clear definition of the objective and approach of the work discussed, pointing out material that is new, and present sufficient details regarding results. The presentation and manuscript must not be of a commercial nature nor can it have been previously published. The symposium chairman will notify you via postal mail by June 1, 2013, of your paper's acceptability for presentation at the symposium.

Symposium presenters are required to submit their papers to the Selected Technical Paper (STP), an online and printed, peer-reviewed publication for the international scientific and engineering community. Manuscripts to be peer reviewed for the STP are due online no later than Sept. 8, 2013.

   

Concrete Reinforcing Steel Institute: Use Inch-Pound Markings

The Concrete Reinforcing Steel Institute (CRSI) Board of Directors is urging all CRSI producer members to revert to an inch-pound bar marking system for all sizes and grades of deformed reinforcing steel products. CRSI members produce more than 90 percent of domestic reinforcing steel.

The intention of this resolution is for all new rollings of reinforcing steel products to be marked with inch-pound bar markings no later than Jan. 1, 2014. Providing a 25-month phase in period should permit producer members sufficient time to re-tool finish roll inventory to the inch-pound marking system as rolls need to be replaced, significantly reducing or eliminating the need to unnecessarily cut new rolls to meet the resolution.

As the ASTM specifications for reinforcing steel products permit reinforcing bars to be marked in either soft metric, or inch-pound markings, existing inventory of soft metric bars can continue to be sold alongside inch-pound marked bars during and after the Jan. 1, 2014, phase-in target.

The intention of this resolution is to reduce confusion and the chance of errors or delays from the construction supply chain. CRSI members are strongly encouraged to revert to the inch-pound marking system for steel reinforcing bars as soon as practical to minimize any additional confusion to the supply chain of steel reinforcing bars.

This change is the result of several actions. The Federal Highway Administration no longer mandates metrification of federally funded road and bridge construction projects and all state Departments of Transportation no longer require materials to be specified and sourced in metric sizes/quantities. Additionally, a large majority of the non-governmental construction community never adopted metric measurements in their plans and specifications. The American Concrete Institute (ACI), through their Technical Activities Committee, has strongly encouraged CRSI members to mark reinforcing bars with traditional inch-pound size designations. ACI is the standards body within the United States responsible for developing the concrete building code. The concrete building code and other ACI documents reference the inch-pound size as the primary designation.

ASTM Concrete Committee at Work on Proposed Lightweight Aggregates Standard

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 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.

Lang Receives ASTM Award

Nicholas R. Lang, manager of the Research and Development Laboratory at the National Concrete Masonry Association in Herndon, Va., has received the 2011 President’s Leadership Award from ASTM International.

Established in 2007, the President’s Leadership Award recognizes individuals early in their ASTM careers who have significantly advanced the Society’s mission through extraordinary accomplishment, example and vision. T. Russell Gentry, Ph.D., an associate professor in the School of Architecture at the Georgia Institute of Technology in Atlanta, Ga., also was honored this year.

Lang has been a member of ASTM International since 2006. He serves as a member at large on Committees C12 on Mortars and Grouts for Unit Masonry and C15 on Manufactured Masonry Units, and is chairman of Subcommittee C15.03 on Concrete Masonry Units and Related Units. He has chaired several C12 and C15 task groups, and also is a member of Committees C09 on Concrete and Concrete Aggregates and E06 on Performance of Buildings.

After graduating from the University of Pittsburgh in 2003 with a bachelor’s degree in materials science and engineering, Lang accepted the position of laboratory inspector at the ASTM International Cement and Concrete Reference Laboratory (CCRL) in Gaithersburg, Md. In 2006, he joined the National Concrete Masonry Association as a research engineer, and he assumed his current role in 2008. As manager of the Research and Development Laboratory, he oversees a staff of technicians and masons in evaluating the performance of concrete masonry products and wall systems in both a contract capacity and on behalf of the concrete masonry industry.

ASTM Awards Dr. Margaret Thomson

ASTM International Committee C12 on Mortars and Grouts for Unit Masonry has recognized Margaret Thomson, Ph.D., director of New Business Development, Technical Services, at Lhoist North America in Fort Worth, Texas, with the ASTM Award of Merit and accompanying title of fellow. The Award of Merit is the highest organizational recognition for individual contributions to ASTM standards activities.

Committee C12 cited Thomson, a member of ASTM International since 1996, for her exceptional leadership and commitment to standards development for the committee, especially in the area of historic mortars. In addition to her work for C12, where she currently serves as a member at large, Thomson is vice chairman of Committee C07 on Lime and chairman of Subcommittee C07.06 on Physical Tests. C07 has honored her with two Awards of Appreciation for her contributions. She also works on Committees C01 on Cement, C15 on Manufactured Masonry Units and E60 on Sustainability.

Thomson joined Lhoist North America (formerly Chemical Lime Co.) as technical manager of Chemstar Type S Hydrated Lime in 1996. She was promoted to technical director, Western Sales Division, in 2009, and received her current title in 2011. Before Lhoist, she was a research scientist focusing on performance of lime-based mortar for masonry at the National Research Council Canada’s Institute for Research in Construction. Thomson received a B.Sc. with honors and a Ph.D. in geology from the University of Western Ontario, London, Ontario, Canada.

In addition to ASTM International, Thomson is a member of the Canadian Standards Association, the Masonry Society, the American Concrete Institute and the International Union of Laboratories and Experts in Construction Materials, Systems and Structures (RILEM).