【国外标准】 Standard Test Method for Cement Content of Hardened Soil-Cement Mixtures

5.1 This test method determines cement content in mixtures of cement with soil or aggregate by chemical analysis. It was developed primarily for testing samples for which a significant degree of cement hydration or hardening has taken place. Test Methods D2901 or D5982 may be used for determining cement content of freshly mixed soil-cement mixtures.5.2 This test method is based on determination by chemical analysis of the calcium oxide (CaO) content of the sample. The method may not be applicable to soil-cement materials containing soils or aggregates which yield significant amounts of dissolved calcium oxide (CaO) under the conditions of the test.NOTE 1: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing and sampling. Users of this standard are cautioned the compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors: Practice D3740 provides a means of evaluating some of these factors.NOTE 2: Analysis using X-ray fluorescence in accordance with C114 may also be used for determination of calcium oxide (CaO) content of hardened soil-cement.1.1 This test method covers the determination by chemical analysis of cement content of hardened soil-cement mixtures.1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026.1.3.1 For purposes of comparing a measured or calculated value(s) with the specific limits, the measured or calculated value(s) shall be rounded to the nearest decimal or significant digits in the specific limits.1.3.2 The procedures used to specify how data are collected/recorded or calculated in the standard are regarded as industry standard. In addition they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analysis methods for the engineering design.1.4 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. For specific hazard precautions, see Section 7.1.5 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.