型钢高强混凝土梁力学性能试验研究

EXPERIMENTAL STUDY ON MECHANICAL BEHAVIOR OF SRHSC BEAM

基于19榀型钢高强混凝土简支梁的力学性能试验,观察了诸试件的裂缝开展模式及破坏形态,揭示了影响梁力学性能的主要因素,探讨了混凝土强度、含钢率、剪跨比、荷载类型、剪切连接方式及宽度比(型钢翼缘宽度与梁宽之比)对梁力学性能的影响规律,给出了不同连接方式下型钢与混凝土界面间的剪切计算方法。依据现有型钢混凝土梁承载能力计算方法,通过引入截面对称性影响系数以考虑型钢截面形式变化对构件承载力的影响,建立了中和轴通过型钢腹板时型钢高强混凝土梁正截面抗弯承载力的计算公式。建议公式计算值与试验实测值吻合较好,表明该文提出的计算公式具有较高的精度。研究将为型钢高强混凝土梁相关计算理论的建立提供理论依据。

Experiments of 19 steel reinforced high-strength concrete （SRHSC） beams were carried out, the crack development and failure mode were observed, and main factors which affect the mechanical behavior of SRHSC beams were revealed. Then the relationships between concrete strength, steel ratio, shear span ratio, loading type, shear connection type and flange width ratio （ratio of steel flange width to beam width） were obtained. Methods for calculating the shear force at the interface of steel and concrete were proposed for different shear connection types. To modify the existing calculation methods for SRC beams, this paper introduced the influence coefficient of cross-section symmetry to reflect the effects of steel position and form on the bearing capacity of SRC beams, then the formulas for calculating bending capacity of SRHSC beams were established for the case that the neutral axis lies in steel web. The calculated values agreed well with the real values, showing the high accuracy of the proposed formulas. This research will provide theoretical support for analyzing mechanical behaviors of SRHSC beams.