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2014SprShotcreteEMag

Shotcrete Corner • Canadian Standards Association (CSA) nationally recognized standards such as ASTM, • Association Francaise de Normalisation BS, and ISO. Be careful when evaluating a test (AFNOR); and that the proper conversions are done, and that the • Japanese Industrial Standard Committee (JIS). test results are in line with the specific standards In addition, there is the International Organization requirements. For example, ACI 318 specifies a for Standardization (ISO), which has adopted maximum of 0.06% water-soluble chloride ion many of the above standards. content in a concrete mixture by weight of cement China, as an example, has its own national for prestressed concrete and as measured by standards, called GB, from Guo Biao, meaning ASTM C1218. One should not use BS 1881 to National Standard. The GB 50086-2001 is meet ACI 318 requirements, for while it also specifically design for shotcrete, called “Standard measures chloride content, it does so in a substan- for Rock Anchor Shotcrete Support.” It was tially different way than ASTM and with differing developed based on BS, EN (European Stan- results. Standards that seem similar can vary dard), and ASTM test methods. Many countries significantly. Know the units and how the tests like China and Qatar have standards that specify are conducted. tests from multiple organizations such as BS, EN, In the Summer 2013 issue of Shotcrete and ASTM. magazine, Charles Hanskat updated readers on Many countries like Qatar hire design consultants U.S. shotcrete standards and tests.2 Below is a from other countries who specify standards that condensed summary of his list. they know. Thus, a project in Qatar or Singapore ACI (www.concrete.org) may have common ASTM tests specified if the • ACI 506.2-13, “Specification for Shotcrete”— designers are from the United States. recently released When comparing test results from different • ACI 506R-XX, “Guide to Shotcrete”—in parts of the world, it is important to know how ballot, needs photos tests are performed and the units used. Conversions • ACI 506.1 R-08, “Committee Report on Fiber- may be needed, and not just from metric to English. Reinforced Shotcrete” For instance, the British Standards (BS) for concrete • ACI 506.4R-94, “Guide to Evaluation of compressive strength are much different than the Shotcrete” ASTM concrete compressive strength standard. • ACI 506.5R-09, “Guide for Specifying Under- BS concrete compression is done on a concrete ground Shotcrete” cube 6 x 6 x 6 in. (150 x 150 x 150 mm), not a ASTM International (www.ASTM.org) cylinder whose height is twice the diameter (2:1). • ASTM C1140/C1140M-11, “Practice for Pre- To compare BS results to U.S. units results paring and Testing Specimens from Shotcrete requires two conversions. First, a conversion is Test Panels” needed to compare testing a cube to testing a 2:1 • ASTM C1141/C1141M-08, “Specification for cylinder. The second conversion is simply con- Admixtures for Shotcrete” verting from metric to English. As an example, • ASTM C1385/C1385M-10, “Practice for QSC 2010 C40 concrete is 40 N/mm2 compression Sampling Materials for Shotcrete” on a 6 x 6 x 6 in. (150 x 150 x 150 mm) cube, • ASTM C1436 -08, “Specification for Materials which is equivalent to 32 MPa 2:1 on a 6 in. wide for Shotcrete” x 12 in. tall (150 x 300 mm) cylinder, which in • ASTM C1480/C1480M-07, “Specification for turn is equivalent to 4600 psi on a 6 x 12 in. cyl- Packaged, Pre-Blended, Dry, Combined inder (40 N/mm2 cube = 32 MPa cylinder = Materials for Use in Wet or Dry Shotcrete 4600 psi cylinder). Application” • ASTM C1604/C1604M-05, “Standard Test Summary Method for Obtaining and Testing Drilled Testing provides verification to designers and Cores of Shotcrete” confirmation to contractors. The driving forces • ASTM C1550-12a, “Test Method for Flexural behind testing around the world are specific toughness of Fiber-Reinforced Concrete project needs, and the local codes and standards (Using Centrally Loaded Round Panel)” a project must meet will likely be specified by the • ASTM C1609/C1609M-12, “Standard Test local government regulatory agency. Standards Method for Flexural Performance of Fiber- chosen by different countries often dictate testing, Reinforced Concrete Using Beam with Third- although more countries are choosing to use Point Loading” Shotcrete • Spring 2014 23


2014SprShotcreteEMag
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