【国外标准】 Standard Specification for Packaged, Pre-Blended, Dry, Combined Materials for Use in Wet or Dry Shotcrete Application (Withdrawn 2021)

This specification covers laboratory performance standards for pre-blended, dry, packaged, combined materials for use in wet or dry shortcrete applications. Dry packaged shortcrete materials are categorized as to type and grade. Basic materials shall meet the requirements of this specification. Additional materials shall be permitted only if adequate test data are available to insure that the ingredient has no deleterious effects on the specified properties. Cementitious materials and aggregates shall be measured by mass (or by volume). Volumetric measurement shall be calibrated by mass. Fibres are measured by mass. Admixtures are measured by mass or volume. Shortcrete ingredients shall be thoroughly blended at a central location. Mixer performance tests shall be performed to establish the mixing time suitable for uniformity of mixing. Type FA and CA shortcrete shall meet the requirements when mixed and tested in accordance with the procedure for mixing and testing. Grade GU shortcrete shall meet the general requirements for type FA or type CA shortcrete. Grade SR shortcrete shall have sulfate resistance. Grade LP shortcrete shall have a very low chloride penetrability rating. Grade FR shotcrete shall have fiber reinforcement with a minimum average residual (Grade FR Class I) and flexural strength (Grade FR Class II) when tested.1.1 This specification covers laboratory performance standards for pre-blended, dry, packaged, combined materials for use in wet or dry shotcrete applications that are delivered to a purchaser with the ingredients uniformly mixed. The use of supplemental materials, placement, curing, or protection of the shotcrete after delivery to the purchaser is not addressed by this specification.1.2 The values stated in either SI units or inch-pound units shall be regarded separately as standard. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.1.3 The following safety hazards caveat pertains only to the test method portion of this specification: 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.