The present study investigates tensile properties of concrete with and without fly ash at early age, such as tensile Young’s modulus, strength and creep. Some Young’s modulus of fly ash concrete for thermal crack analysis was compared with the tensile Young’s modulus, secant modulus, initial tangent modulus and linear modulus obtained from the direct tension test and compression test. The tensile creep test was also performed to obtain the specific creep behavior considering decrease in elastic strain due to stiffness development at early age during creep test. The results show that the Young’s modulus for crack evaluation can be obtained from the compression test based on the stress range less than the splitting tensile strength, while the compressive secant modulus was smaller than the tensile Young’s modulus. The decrease of the elastic strain at early age contributes more to the evaluation of the tensile creep than the use of the fly ash mixing.

中文翻译：

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粉煤灰混凝土早期拉伸力学性能的热应力分析。

本研究调查了早期有无飞灰的混凝土的拉伸性能，例如拉伸杨氏模量，强度和蠕变。比较了用于热裂纹分析的粉煤灰混凝土的一些杨氏模量与直接拉伸试验和压缩试验获得的拉伸杨氏模量，割线模量，初始切线模量和线性模量。考虑到蠕变试验中由于早期时的刚度发展而导致的弹性应变降低，还进行了拉伸蠕变试验以获得特定的蠕变行为。结果表明，基于小于破裂抗拉强度的应力范围，可通过压缩试验获得用于评估裂纹的杨氏模量，而压缩割线模量小于拉伸杨氏模量。