Rock Products

AUG 2012

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Page 57 of 59

Who are Those ASTM Policy Wonks ( And What are They Up To?) By Mark S. Kuhar Many people wonder about The Ameri‐ can Society for Testing and Materials (ASTM). They just assume that those involved with ASTM committees are like mad scientists sitting in laborato‐ ries somewhere analyzing arcane data points to micromanage industry knowledge of construction materials' performance characteristics. ASTM is actually a globally recognized leader in the development and delivery of international voluntary consensus standards. More than 12,000 ASTM standards are used around the world to improve product quality, enhance safety, facilitate market access and trade and build consumer confidence. There have been some recent develop‐ ments in the area of aggregates. ASTM Subcommittee C09.20 ASTM Subcommittee C09.20 on Nor‐ mal Weight Aggregates is developing a standard to distinguish between harm‐ ful and non‐harmful fines in construc‐ tion aggregate. Ready mixed, aggregate and asphalt producers will use the ASTM WK36804 Test Method for Rapid De‐ termination of the Methylene Blue Value for Fine Aggregate and Mineral Filler to qualify new material sources and in routine quality control proce‐ dures. The proposed standard entails a method that can be performed in the field in about 10 minutes and does not involve the titration and visual assess‐ ments typically associated with such testing. "The methylene blue test has been shown to be an effective indicator of the amount and type of clay present in aggregate and can therefore help to distinguish between harmful and bene‐ ficial fines," said C09.20 member and W.R. Grace and Co. Research & Devel‐ 56 ROCKproducts • AUGUST 2012 opment Director Eric Koehler. "Once it has been approved, the proposed stan‐ dard will enable the use of a wider range of sands and limestone fillers in concrete, while also ensuring that these aggregates are of high quality. This will prevent the waste of non‐ detrimental fines, which must cur‐ rently be washed out of sand indiscriminately, [and] result in more sustainable use of limited aggregate re‐ sources." Subcommittee D04.94 Buyers and sellers of road and paving materials will be the primary users of a proposed standard under Subcommit‐ tee D04.94 on Statistical Procedures and Evaluation of Data, part of ASTM International Committee D04 on Road and Paving Materials. ASTM WK35585, Practice for Data Collection and Resolving Test Result Differences Between Buyer and Seller, will provide a rational dispute resolu‐ tion practice for contractors or mate‐ rial suppliers and agencies when numbers from two different laborato‐ ries on the same product differ. "The goal is to provide a systematic way to resolve differences in a professional atmosphere," said D04 member James Moulthrop, P.E., a senior consultant with Fugro Consultants Inc., Austin, Texas. Among the procedures to be described in WK35585 are: documentation to de‐ termine acceptable quality material; sample chain of custody; determina‐ tion of whether data comes from the same population; determination of dif‐ ferences between sets of data; and, de‐ termination of assignable cause(s) for differences between test results. "The proposed standard has been needed to provide users of ASTM Com‐ mittee D04 standards a rational sequen‐ tial process for resolving test result dif‐ ferences," said D04.94 Chairman Ervin Dukatz, P.E., of Mathy Construction Co., Onalaska, Wis., adding that subcommit‐ tee participation is open to paving ma‐ terial interests. Subcommittee E60.01 A new ASTM International standard will aid in the selection of lightweight aggre‐ gate best suited for use in the design and construction of vegetative roof sys‐ tems. ASTM E2788, Specification for Use of Expanded Shale, Clay and Slate (ESCS) as a Mineral Component in the Growing Media and Drainage Layer for Vegetative (Green) Roof Systems, was developed by Subcommittee E60.01 on Buildings and Construction, part of ASTM International Committee E60 on Sustainability. Specifiers, blenders and users of light‐ weight growing media for green roof applications will be the primary users of ASTM E2788. According to Chuck Friedrich, an E60.01 member, ASTM E2788 pro‐ vides typical gradations, physical and chemical properties of the rotary kiln expanded lightweight aggregates that can be used as a lightweight fill, drainage material or as growing media component for green roofs. "ASTM E2788 can be used to select the size and type of lightweight aggregate best suited for a project," said Friedrich, of the Carolina Stalite Co. "The selection will be determined by local availability, but the new standard gives a broad scope of the properties that will allow most ESCS products in each region to meet the specification." According to Friedrich, ESCS is regu‐ larly manufactured for use in the light‐ weight concrete industry but is also desirable for most green roof media. E

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