Source: ASTM International, West Conshohocken, Pa.
A proposed standard, WK37029, Test Method for Measurement of Mass Loss Versus Time for One-Dimensional Drying of Saturated Concretes, will enable ready mixed producers to characterize the drying behavior of new and existing concrete mixture proportions.
“[It] is being developed to support the modeling of concrete service life,” says Dale Bentz, chair of a WK37029 task group under ASTM Subcommittee C09.66 on Concrete’s Resistance to Fluid Penetration. In many applications, concrete is exposed to wetting and drying conditions such that the slab or structure is partially saturated, notes Bentz, a chemical engineer at National Institute for Standards and Technology Engineering Laboratory/Materials and Structural Systems Division.
The proposed standard can provide information on the mass loss versus time (drying) behavior of an initially saturated concrete specimen exposed to one-dimensional drying in a controlled temperature and relative humidity environment. “The information can be used to directly assess the drying propensity of a given concrete mixture, [and] could be valuable for industrial flooring applications where quick drying is often desirable,” explains Bentz, adding that the data can also be analyzed for estimates of the mixture’s vapor diffusivity and liquid permeability characteristics.
Along with ready mixed producers, testing laboratories and concrete consultants will be the primary ASTM WK37029 users. Subcommittee C09.66 remains open to stakeholders interested in participating in the proposed standard and future efforts, especially representatives of testing labs. ASTM Subcommittee C09.66 is part of ASTM C09 Committee on Concrete and Concrete Aggregates, whose next meeting is December 8-11 in Jacksonville, Fla. Contacts: Dale Bentz, NIST, Gaithersburg, Md., 301/975-5865; [email protected]; ASTM Committee C9 staff liaison, Scott Orthey, 610/832-9730; [email protected].