Rebar-reinforced coarse aggregate ultra-high-performance concrete (R-CA-UHPC) has been used in the construction of new structures and strengthening of deteriorated aged infrastructures, and it inevitably sustains tension. To study the tensile behavior of R-CA-UHPC members, axial tensile tests for dog-bone-shaped specimens were designed and conducted. The investigated variables included reinforcement ratio in terms of rebar quantity/diameter, and concrete type (CA-UHPC vs. normal concrete). The test results showed that the improved rebar/CA-UHPC bond property prevents the emergence of splitting cracks, but intensifies the crack localization for CA-UHPC and strain concentration for rebar after yielding. Moreover, the restrained effect of rebar on free shrinkage of CA-UHPC leads to a decrease in the first cracking strength for R-CA-UHPC members. Based on the established development functions of elastic modulus, autogenous shrinkage, and tensile creep for CA-UHPC, the restrained effect was quantified according to Dischinger's-differential-equation-based theoretical analysis. Finally, the models to predict the first cracking stresses/strains and the yielding loads of the R-CA-UHPC members were developed and validated.

中文翻译：

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钢筋粗骨料超高性能混凝土（R-CA-UHPC）构件的拉伸行为：实验和抑制收缩徐变效应


钢筋粗骨料超高性能混凝土（R-CA-UHPC）已被用于建造新结构和加固老化的基础设施，它不可避免地会承受紧张。为了研究 R-CA-UHPC 构件的拉伸行为，设计并进行了狗骨形试样的轴向拉伸试验。研究的变量包括钢筋数量/直径的配筋率和混凝土类型（CA-UHPC 与普通混凝土）。测试结果表明，改进的钢筋/CA-UHPC粘结性能防止了劈裂裂纹的出现，但加剧了CA-UHPC的裂纹局部化和屈服后钢筋的应变集中。此外，钢筋对CA-UHPC自由收缩的抑制作用导致R-CA-UHPC构件的首次开裂强度下降。基于已建立的CA-UHPC的弹性模量、自收缩和拉伸蠕变的发展函数，根据基于Dischinger微分方程的理论分析对约束效果进行了量化。最后，开发并验证了预测 R-CA-UHPC 构件的首次开裂应力/应变和屈服载荷的模型。