掺复合镍铁渣混凝土梁柱中节点变形特性

复合镍铁渣混凝土与普通混凝土在强度等同条件下，由于泌水效应，前者与水平钢筋的粘结强度显著弱于后者。针对此特性，基于已有试验，分析了掺复合镍铁渣混凝土梁柱中节点的变形特性。节点的变形主要归结为附属梁体的弯曲变形和梁纵筋滑移引起的梁柱界面附加转角变形，本文重点分析后者。从试验现象观察来看，梁体的受弯变形并不明显，而梁柱界面附加转角变形明显。采用数值方法分析了不同复合镍铁渣掺量下的梁柱界面附加转角变形对总体变形的影响。研究表明，随着复合镍铁渣掺量的增加，梁柱界面附加转角增加，占整体变形相当大的比例。提出了梁端等效塑性铰模型，确定了塑性铰长度与梁长、复合镍铁渣掺量、梁纵筋直径之间的关系，可以快速评估复合镍铁渣梁柱中节点的极限变形能力。

Deformation characteristics of interior beam-column joints made with composite ferronickel slag concrete

Under the same strength condition, the bond strength between composite ferronickel concrete and horizontal rebar is significantly weaker than that of normal concrete due to bleeding effect. In view of this characteristic and based on the previous test data, the deformation characteristics of the interior beam-column joints made with composite ferronickel concrete are analyzed theoretically. The joint deformation consists mainly of the bending deformation of the attached beam and the additional angle deformation at the beam-column interface, this paper focuses on the latter analysis. From the observation of the experimental phenomena, the bending deformation of the beam is not obvious, while the additional angle deformation at the beam-column interface is obvious. Using the numerical method verified by the experimental results, the proportion of the additional rotation angle deformation at the beam-column interface to the total deformation was analyzed. Results showed that with the increase of the composite ferronickel slag content, the additional rotation angle at the beam-column interface increases, which accounts for a large proportion of the overall deformation. The equivalent plastic hinge model at beam end was put forward, which can quickly evaluate the ultimate deformation capacity of interior beam-column joints made with composite ferronickel slag concrete. The plastic hinge length as a function of the beam length, the ferronickel slag content, and the beam longitudinal rebar diameter was determined.