1.1 本规程提供了通过成熟度法估算混凝土强度的程序。成熟指数用温度-时间因子或指定温度下的等效年龄表示。 1.2 该实践要求在实验室建立混凝土混合物的强度-成熟度关系，并记录待估算强度的混凝土的温度历史。 1.3 以国际单位制表示的数值将被视为确定成熟度指数的标准。为此目的，不包括其他计量单位。然而，在发展力量的过程中，表达力量的单位体系没有任何限制- 到期关系。 1.4 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 ( 警告- 新鲜的水硬性胶结混合物具有腐蚀性，长时间接触可能会导致皮肤和组织化学烧伤。 2. ) 1.5 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 该实践可用于估算混凝土的现场强度，以便开始关键施工活动，例如:( 1. )拆除模板并重新支护；( 2. )钢筋束的后张拉；( 3. )终止寒冷天气防护；和( 4. )道路通车。 5.2 本规程可用于估算在非标准温度条件下固化的实验室试样的强度。 5.3 成熟度法的主要局限性是:( 1. )混凝土必须保持在允许水泥水化的条件下；( 2. )该方法未考虑早期- 老化混凝土温度对长期强度的影响（见 附注6 ) ( 3. , 4. ) ; 和( 3. )该方法需要补充现场混凝土潜在强度的其他指标。 5.4 估计强度的准确性部分取决于使用适当的参数（基准温度或 Q )对于第节中描述的成熟度函数 6. . 注1: 基准温度的近似值， T o ，以及 Q -在中使用的值 等式1 或 公式2 分别在中给出 附录X2 . 如果需要强度估计的最大精度，则适当的 T o 或 Q 对于特定的混凝土混合物，可使用中给出的程序确定 附录X1 .

1.1 This practice provides a procedure for estimating concrete strength by means of the maturity method. The maturity index is expressed either in terms of the temperature-time factor or in terms of the equivalent age at a specified temperature. 1.2 This practice requires establishing the strength-maturity relationship of the concrete mixture in the laboratory and recording the temperature history of the concrete for which strength is to be estimated. 1.3 The values stated in SI units are to be regarded as standard for determining the maturity index. No other units of measurement are included for this purpose. There is, however, no restriction on the system of units for expressing strength in developing the strength-maturity relationship. 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. ( Warning— Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and tissue upon prolonged exposure. 2 ) 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. ====== Significance And Use ====== 5.1 This practice can be used to estimate the in-place strength of concrete to allow the start of critical construction activities such as: ( 1 ) removal of formwork and reshoring; ( 2 ) post-tensioning of tendons; ( 3 ) termination of cold weather protection; and ( 4 ) opening of roadways to traffic. 5.2 This practice can be used to estimate strength of laboratory specimens cured under non-standard temperature conditions. 5.3 The major limitations of the maturity method are: ( 1 ) the concrete must be maintained in a condition that permits cement hydration; ( 2 ) the method does not take into account the effects of early-age concrete temperature on the long-term strength (see Note 6 ) ( 3 , 4 ) ; and ( 3 ) the method needs to be supplemented by other indications of the potential strength of the field concrete. 5.4 The accuracy of the estimated strength depends, in part, on using the appropriate parameters (datum temperature or value of Q ) for the maturity functions described in Section 6 . Note 1: Approximate values of the datum temperature, T o , and the Q -value for use in Eq 1 or Eq 2 , respectively, are given in Appendix X2 . If maximum accuracy of strength estimation is desired, the appropriate values of T o or Q for a specific concrete mixture may be determined using the procedures given in Appendix X1 .