Abstract This paper presents a 12-year-long creep and shrinkage experimental campaign on cylindrical and prismatic concrete samples under uniaxial and biaxial stress, respectively. The motivation for the study is the need for predicting the delayed strains and the pre-stress loss of concrete containment buildings of nuclear power plants. Two subjects are central in this regard: the creep strain's long-term evolution and the creep Poisson's ratio. A greater understanding of these areas is necessary to ensure reliable predictions of the long-term behavior of the concrete containment buildings. Long-term basic creep appears to evolve as a logarithm function of time in the range of 3 to 10 years of testing. Similar trends are observed for drying creep, autogenous shrinkage, and drying shrinkage testing, which suggests that all delayed strains obtained using different loading and drying conditions originate from a common mechanism. The creep Poisson's ratio derived from the biaxial tests is approximately constant over time for both the basic and drying creep tests (creep strains corrected by the shrinkage strain). It is also shown that the biaxial non-drying samples undergo a significant increase in Young's modulus after 10 years.

中文翻译：

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单轴和双轴荷载下混凝土徐变的 12 年 EDF 研究

摘要 本文介绍了分别在单轴和双轴应力下对圆柱形和棱柱形混凝土样品进行了为期 12 年的蠕变和收缩实验。该研究的动机是需要预测核电站混凝土安全壳建筑物的延迟应变和预应力损失。在这方面有两个主题是核心：蠕变应变的长期演变和蠕变泊松比。需要对这些领域有更深入的了解，以确保对混凝土安全壳建筑物的长期行为进行可靠的预测。长期基本蠕变似乎在 3 到 10 年的测试范围内作为时间的对数函数演变。在干燥蠕变、自收缩和干燥收缩测试中观察到类似的趋势，这表明使用不同的加载和干燥条件获得的所有延迟菌株都源自一个共同的机制。对于基本蠕变试验和干燥蠕变试验（蠕变应变由收缩应变校正），从双轴试验得出的蠕变泊松比随时间近似恒定。还表明，双轴非干燥样品在 10 年后杨氏模量显着增加。