Wang En, Liu Yicen, Lyu Fei, Ding Faxing, Xu Yunlong
School of Civil Engineering, Central South University, Changsha 410075, China.
Engineering Technology Research Center for Prefabricated Construction Industrialization of Hunan Province, Changsha 410075, China.
Materials (Basel). 2021 Dec 26;15(1):154. doi: 10.3390/ma15010154.
Recycled aggregate concrete-filled steel tubular (RACFST) columns are widely recognized as efficient structural members that can reduce the environmental impact of the building industry and improve the mechanical behavior of recycled aggregate concrete (RAC). The objective of this study is to investigate the behavior of recycled aggregate concrete-filled circular steel tubular (RACFCST) stub columns subjected to the axial loading. Three-dimensional finite element (FE) models were established using a triaxial plastic-damage constitutive model of RAC considering the replacement ratio of recycled aggregates. The FE analytical results revealed that the decreased ultimate bearing capacity of RACFCST stub columns compared with conventional concrete infilled steel tubular (CFST) columns was mainly due to the weakened confinement effect and efficiency. This trend will become more apparent with the larger replacement ratio of recycled aggregates. A practical design formula of the ultimate bearing capacity of RACFCST stub columns subjected to axial load was proposed on the basis of the reasonably simplified cross-sectional stress nephogram at the ultimate state. The derivation process incorporated the equilibrium condition and the superposition theory. The proposed equation was evaluated by comparing its accuracy and accessibility to some well-known design formulae proposed by other researchers and some widely used design codes.
再生骨料钢管混凝土（RACFST）柱被广泛认为是高效的结构构件，它可以减少建筑行业对环境的影响，并改善再生骨料混凝土（RAC）的力学性能。本研究的目的是研究再生骨料圆形钢管混凝土（RACFCST）短柱在轴向荷载作用下的性能。考虑再生骨料取代率，采用RAC的三轴塑性损伤本构模型建立了三维有限元（FE）模型。有限元分析结果表明，与传统钢管混凝土（CFST）柱相比，RACFCST短柱的极限承载力降低主要是由于约束效应和效率减弱。随着再生骨料取代率的增大，这种趋势将更加明显。基于极限状态下合理简化的截面应力 nephogram，提出了RACFCST短柱轴向荷载作用下极限承载力的实用设计公式。推导过程结合了平衡条件和叠加理论。通过将其准确性和易用性与其他研究人员提出的一些著名设计公式以及一些广泛使用的设计规范进行比较，对所提出的方程进行了评估。
