1.1 本试验方法包括测定承受持续纵向压缩载荷的模制混凝土圆柱体的蠕变。该试验方法仅限于最大骨料尺寸不超过50 mm[2 in.]的混凝土。 1.2 本标准的文本是指提供解释性材料的注释和脚注。这些注释和脚注（不包括表和图中的注释和脚注）不应被视为本标准的要求。 1.3 单位-- 以国际单位制或英寸磅单位表示的数值应单独视为标准。每个系统中规定的值不一定是完全相等的； 因此，为了确保符合标准，每个系统应独立使用，并且不得将两个系统的值组合使用。将两个系统的值合并可能导致不符合标准。 1.4 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者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。 1.5 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 4.1 该试验方法测量了在任意一组受控环境条件下，混凝土在选定龄期的荷载引起的时间相关压缩应变。 4.2 该试验方法可用于比较不同混凝土的蠕变电位。可以使用所开发的方程（或图形图），根据大块非钢筋混凝土结构内的应变数据计算应力。对于大多数特定的设计应用，必须修改本文中规定的测试条件，以更接近地模拟原型结构的预期固化、热、暴露和加载老化条件。 ACI SP-135《混凝土蠕变和收缩研讨会:材料和环境的影响》介绍了材料和环境参数的当前理论和影响。 3. 4.3 在缺乏关于蠕变现象的令人满意的假设的情况下，已经制定了许多假设，这些假设通常已通过测试和经验得到证实。 4.3.1 蠕变与0到40的应力成正比 % 混凝土抗压强度。 4.3.2 在混凝土中通常使用的糊状物含量范围内，蠕变与糊状物含量成正比。因此，含有最大尺寸大于50毫米[2英寸骨料的混凝土混合物的蠕变特性。 ]可以根据通过湿法筛分获得的-50毫米[减2英寸]级分的蠕变特性来确定。将特性值乘以全混凝土混合物中水泥浆含量（体积比）与筛分样品浆含量的比值。 4.4 对数表达式的使用（第节 9 )并不意味着蠕变-应变-时间关系必然是一个精确的对数函数；然而，在一年的时间里，该表达式以足够的精度近似于正常的蠕变行为，从而可以计算出对比较混凝土有用的参数。 4.5 没有数据支持将本试验结果外推到张力或扭转。

1.1 This test method covers the determination of the creep of molded concrete cylinders subjected to sustained longitudinal compressive load. This test method is limited to concrete in which the maximum aggregate size does not exceed 50 mm [2 in.]. 1.2 The text of this standard refers to notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard. 1.3 Units— The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. Combining values from the two systems may result in non-conformance with the standard. 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. 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 ====== 4.1 This test method measures the load-induced time-dependent compressive strain at selected ages for concrete under an arbitrary set of controlled environmental conditions. 4.2 This test method can be used to compare creep potentials of different concretes. A procedure is available, using the developed equation (or graphical plot), for calculating stress from strain data within massive non-reinforced concrete structures. For most specific design applications, the test conditions set forth herein must be modified to more closely simulate the anticipated curing, thermal, exposure, and loading age conditions for the prototype structure. Current theories and effects of material and environmental parameters are presented in ACI SP-135, Symposium on Creep and Shrinkage of Concrete: Effect of Materials and Environment. 3 4.3 In the absence of a satisfactory hypothesis governing creep phenomena, a number of assumptions have been developed that have been generally substantiated by test and experience. 4.3.1 Creep is proportional to stress from 0 to 40 % of concrete compressive strength. 4.3.2 Creep has been conclusively shown to be directly proportional to paste content throughout the range of paste contents normally used in concrete. Thus, the creep characteristics of concrete mixtures containing aggregate of maximum size greater than 50 mm [2 in.] may be determined from the creep characteristics of the minus 50-mm [minus 2-in.] fraction obtained by wet-sieving. Multiply the value of the characteristic by the ratio of the cement paste content (proportion by volume) in the full concrete mixture to the paste content of the sieved sample. 4.4 The use of the logarithmic expression (Section 9 ) does not imply that the creep strain-time relationship is necessarily an exact logarithmic function; however, for the period of one year, the expression approximates normal creep behavior with sufficient accuracy to make possible the calculation of parameters that are useful for the purpose of comparing concretes. 4.5 There are no data that would support the extrapolation of the results of this test to tension or torsion.