马福栋, 邓明科, 杨勇. 超高性能混凝土装配整体式框架梁柱节点抗震性能研究[J]. 工程力学, 2021, 38(10): 90-102. DOI: 10.6052/j.issn.1000-4750.2020.09.0682
引用本文: 马福栋, 邓明科, 杨勇. 超高性能混凝土装配整体式框架梁柱节点抗震性能研究[J]. 工程力学, 2021, 38(10): 90-102. DOI: 10.6052/j.issn.1000-4750.2020.09.0682
MA Fu-dong, DENG Ming-ke, YANG Yong. SEISMIC EXPERIMENTAL STUDY ON A UHPC PRECAST MONOLITHIC CONCRETE BEAM-COLUMN CONNECTION[J]. Engineering Mechanics, 2021, 38(10): 90-102. DOI: 10.6052/j.issn.1000-4750.2020.09.0682
Citation: MA Fu-dong, DENG Ming-ke, YANG Yong. SEISMIC EXPERIMENTAL STUDY ON A UHPC PRECAST MONOLITHIC CONCRETE BEAM-COLUMN CONNECTION[J]. Engineering Mechanics, 2021, 38(10): 90-102. DOI: 10.6052/j.issn.1000-4750.2020.09.0682

超高性能混凝土装配整体式框架梁柱节点抗震性能研究

SEISMIC EXPERIMENTAL STUDY ON A UHPC PRECAST MONOLITHIC CONCRETE BEAM-COLUMN CONNECTION

  • 摘要: 为避免预制构件灌浆套筒连接定位精度要求高、连接质量不易检测等问题,提高梁柱节点的抗震性能,通过5个钢筋搭接后浇UHPC(lap-splice with UHPC,LS-UHPC)装配整体式梁柱节点及1个RC现浇整体式梁柱节点的拟静力试验,研究了LS-UHPC装配整体式梁柱节点的破坏形态、滞回特性、骨架曲线和耗能能力。结果表明:柱纵筋直筋搭接15db,梁下部纵筋设置90°弯钩搭接11db均未出现拔出破坏;梁上部纵筋锚固长度为16.7db或13.6db,虽均小于GB 50010−2010中20db的要求,但由于UHPC较高的粘结强度未发生明显滑移,均表现出较好的延性。节点核心区采用UHPC,受剪承载力明显提高,即使未配箍筋,也可以取得优于普通混凝土现浇节点的性能;节点核心区箍筋和钢纤维掺量的增加,延缓了节点核心区主斜裂缝的形成,提高了节点核心区耐损伤能力,进而提高了梁柱节点的极限位移,延性系数和耗能能力,且适当配置箍筋对核心区耐损伤能力的提高效果更显著;GB 50010−2010低估了UHPC的抗剪贡献,而高估了箍筋的抗剪贡献,美国规范ACI 318-19高估了UHPC的抗剪贡献;利用UHPC的抗压强度和抗拉强度的关系,分别对GB 50010−2010和ACI 318-19进行修正,修正后的ACI 318-19的计算方法较为准确且保守。

     

    Abstract: To avoid problems such as high required-precision and undetectable quality of grouting sleeve connections and to improve the seismic performance of beam-column connections, we studied the failure modes, hysteretic characteristics, skeleton curves, and energy dissipation capacities through the quasi-static tests of six precast concrete beam-column connections and a monolithic beam-column connection. The results indicate that it is feasible to connect the columns and beams by lap-splice with UHPC (LS-UHPC) with straight bars with a lap length of 15db or with 90° hooked bars with a lap length of 11db. No significant slippage occurred because of the high bond strength of UHPC and the specimens exhibited good ductility, although the anchorage lengths of 16.7db and 13.6db for the upper longitudinal bars in the beams did not meet the requirements of 20db specified in the GB 50010−2010. The shear capacity of the joint was significantly improved because of the use of UHPC. It exhibited a better performance than that of ordinary cast-in-place concrete joints, even if no stirrup was provided. The increase of stirrup and steel fiber content in the joint delayed the formation of the main diagonal crack in the joint, improved the damage-resistance capacity of the joint, and improved the ultimate displacement, ductility coefficient and energy consumption capacity of beam-column connection. The stirrups can further improve the damage resistance of the joint. The equations in GB 50010−2010 underestimate the shear contribution of UHPC and overestimate the shear contribution of stirrups, while those in ACI 318-19 overestimate the shear contribution of UHPC in the joint. According to the relationship between compressive and tensile strengths, the equations in GB 50010−2010 and ACI 318-19 are modified. The modified ACI 318-19 equation is more accurate while remains conservative.

     

/

返回文章
返回