【国外标准】 Standard Test Method for Evaluation of Variability of Cement from a Single Source Based on Strength

4.1 This test method is designed to present in a standardized format information on the variability of strength of cement from a single source over a period of time. It can be applied to all hydraulic cements covered in Specifications C150, C595, and C1157. The results derived from this test method are intended for information only and are not requirements of any existing ASTM specification. A specification may refer to this test method to obtain information on the variability of cement from a single source.4.2 The procedure is based on obtaining samples from locations during the delivery of cement to the user and is more representative of the variability of cement used in concrete production than test data reported on mill test reports. Variation determined from the test results is corrected for testing error, therefore giving the user one indicator of the source variation of the cement.NOTE 1: It should be recognized that concrete strength variability is influenced by other factors in addition to cement strength variability.4.3 This test method does not provide information on the relationship between the variability of cement and the variability of concrete properties. The user can, along with supplementary information or correlative testing of concrete properties, develop quantitative estimates of the effects.1.1 This test method covers a procedure for determining the variability of a hydraulic cement produced at a single source using strength tests as the characteristic property. It is intended that this test method normally be used for the predominant cement manufactured at a cement plant. Guidelines for sampling, testing, presentation of results, and evaluation are given.1.2 The values stated in either SI units or inch-pound units are to be regarded separately as the 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. One system of units is used in the Figure and Tables in this standard to illustrate the calculation methods that are applicable independent of the system of units.1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 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.