新型装配式外包U形钢-混组合梁抗剪性能试验研究

Experimental study on novel prefabricated U-shaped steel and reinforced truss concrete composite beams

U形钢-混组合梁凭借承载力高、抗扭刚度大、延性好等优点在工程中广泛应用。但传统外包U形钢-混组合梁由于下部U形梁截面未闭合,导致其对内部混凝土的约束作用有限。同时,组合梁上部面板一般采用混凝土现浇,与装配式建筑发展趋势不契合。针对以上问题,提出了一种适用于装配式建筑的新型外包U形钢-钢筋桁架混凝土组合梁。对其具体构成进行了详细介绍,通过推出试验对该新型组合梁中U形钢梁与混凝土板的剪切破坏机理及协同工作性能进行了深入研究,可为此新型外包U形钢-混凝土组合梁的进一步研究和实际工程应用提供依据。

U-shaped steel and concrete composite beams(USCCB) are widely used in engineering due to its advantages of high bearing capacity, high torsional stiffness and excellent ductility.However, the traditional USCCBs have several deficiencies need to be solved.The restraint effect of the outsourcing U-shaped steel on the internal concrete is limited since its cross-section is unclosed.Meanwhile, the upper flange plate is generally cast-in-situ concrete, which cannot perfectly match the development trend of prefabricated buildings.A novel prefabricated U-shaped steel and reinforced truss concrete composite beam(PUSRTCCB) is thus proposed.Its configuration and structural measures are introduced in detail.The shear failure mechanism and cooperative performance of the U-shaped steel beam and the reinforced truss concrete slab in PUSRTCCBs are studied in depth through the push-out test.The results can provide theoretical and design guidance to the further research and practical engineering application of this kind of PUSRTCCBs.