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Proposed ASTM C09 standard tackles mix material incompatibility

Sources: ASTM International, West Conshohocken, Pa.; CP staff

A working document under ASTM Committee C09 on Concrete and Concrete Aggregates—ASTM WK40615, Practice for Mixing and Comparing Performance of Concrete Materials Using Mini-Mix Mortar Mixtures—enables technologists to detect and address incompatibility issues arising in mix design development.

Due to an increased focus on sustainability in the construction value chain, emergence of new admixture technologies, and decreasing availability of suitable raw materials in some regions, a wider range of mix constituents is now being used in concrete production, according to developers of the proposed standard. ASTM WK40615 will be used to test such materials’ performance, referencing two mortar mixture preparation methods.

“Adding the capability of this standard to the overall quality assurance program of a concrete producer will provide the general public and industry an increased sense of confidence that the concrete supplied for various construction projects will more consistently meet the required performance standards,” says Ara Jeknavorian, Ph.D., who is leading the WK40615 development for the Subcommittee C09.48 on Performance of Cementitious Materials and Admixture Combinations.

A Grace Construction Products veteran now heading a consultancy, he notes that the standard will likely be used to 1) act as an ongoing quality control tool to verify lot-to-lot performance uniformity for various concrete materials; 2) proactively screen the performance of a new or alternate source material under consideration; or, 3) troubleshoot an unexpected performance issue, assuming the materials associated with the problem are still available.

Subcommittee C09.48 is keen on participation from quality control and other technical professionals using paste and mortar mixtures to help predict the effect on concrete performance when a material property changes. “C09.48 is a collaboration between C09 and ASTM Committee C01 on Cement, which underscores the mutual responsibility across material suppliers and testing agencies to help improve the predictability of the performance of concrete materials,” says Jeknavorian. “The work of C09.48 can be greatly enhanced by concrete producers sharing their own experiences in dealing with material incompatibility issues.”

WK40615 will be on the agenda of Subcommittee C09.48’s next meeting, scheduled as part of C09 Committee Week, December 7-10 in New Orleans. Contacts: (technical) Ara Jeknavorian, 617/803-2612, [email protected]; (staff liaison) Scott Orthey, 610/832-9730, [email protected]