【国外标准】 Standard Practice for Fabricating and Testing Specimens of Ultra-High Performance Concrete

4.1 This practice includes procedures for measuring properties of fresh UHPC and procedures for making and testing specimens of hardened UHPC. The practice refers to existing practices and test methods and includes modifications to these referenced standards for application to UHPC.1.1 This practice covers procedures for fabricating and testing specimens in the laboratory and the field using a representative sample of ultra-high performance concrete (UHPC), for the purpose of determining the properties of the material. This practice is applicable to UHPC with a specified compressive strength of at least 120 MPa (17 000 psi), with nominal maximum size aggregate of less than 5 mm [1/4 in.] and a flow between 200 and 250 mm [8 and 10 in.] as measured by the modified flow table test described in Section 6.1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.3 If required results obtained from another standard are not reported in the same system of units as used by this standard, it is permitted to convert those results using the conversion factors found in the SI Quick Reference Guide (1).21.4 The text of this standard references notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of this standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. [WARNING—Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to exposed skin and tissue upon prolonged exposure.3 Hand protection should be worn when handling UHPC.]1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.