New Test Method Generates Service-Life Data for Concrete
C 1556, Test Method for Determining the Apparent Chloride Diffusion Coefficient of Cementitious Mixtures by Bulk Diffusion, provides data for time-to-corrosion service-life calculations for concrete.
This test method determines how fast chloride ion moves in wet concrete, says Matt Miltenberger, P.E., senior project engineer, Master Builders, Inc., Cleveland, who developed the standard with a task group of academics, material engineers, testing laboratories, and representatives from chemical admixture manufacturers. The apparent chloride diffusion coefficient is used to estimate the corrosion service life of new structures, he explains. With this standard, engineers responsible for designing durable concrete structures can specify a concrete property that can be used to calculate how long it will take for corrosion to start.
The test method generates data that can be used to predict the corrosion service life of concrete structures such as seawalls and interstate-highway bridges. As demands for our infrastructure tax dollars increase, demands for more efficient use of public funds is being mandated, Miltenberger says. Coupled with service life estimation and lifecycle cost analysis, project specifications incorporating this standard will help improve the quality of our transportation infrastructure.
The task group developed new standard C 1556 from the Scandinavian standard NT BUILD 443. Currently, consultants are using a multitude of methods to obtain the apparent diffusion coefficient, and each method can produce a different value for the same material, wrote the task group in their rationale for the new standard.
Variations of this test method have been used for more than a decade, Miltenberger adds. However, since the test result depends on the techniques employed while performing the test, test results varied between laboratories. Now that this procedure is standardized, it is hoped that test results will become more consistent between laboratories, thereby, improving the reliability of corrosion service life estimates.
Subcommittee C09.66 on Concretes Resistance to Fluid Penetration will maintain the standard within the guidelines of ASTM Committee C09 on Concrete and Concrete Aggregates.
For further technical information, contact Matt Miltenberger (phone: 216/839-7387). Committee C09 meets June 15-18 in Denver, Colo., and Dec. 7-10 in Tampa, Fla. For membership details, contact Jim Olshefsky, director, Committee Services, ASTM International, West Conshohocken, Pa. (phone: 610/832-9714). //
Copyright 2003, ASTM