卜一之, 刘欣益, 张清华. 基于截面应力法的钢-UHPC组合板初裂荷载计算方法研究[J]. 工程力学, 2020, 37(10): 209-217. DOI: 10.6052/j.issn.1000-4750.2019.12.0738
引用本文: 卜一之, 刘欣益, 张清华. 基于截面应力法的钢-UHPC组合板初裂荷载计算方法研究[J]. 工程力学, 2020, 37(10): 209-217. DOI: 10.6052/j.issn.1000-4750.2019.12.0738
BU Yi-zhi, LIU Xin-yi, ZHANG Qing-hua. CRACKING LOAD CALCULATION FOR STEEL-UHPC COMPOSITE SLABS BASED ON THE SECTION-STRESS METHOD[J]. Engineering Mechanics, 2020, 37(10): 209-217. DOI: 10.6052/j.issn.1000-4750.2019.12.0738
Citation: BU Yi-zhi, LIU Xin-yi, ZHANG Qing-hua. CRACKING LOAD CALCULATION FOR STEEL-UHPC COMPOSITE SLABS BASED ON THE SECTION-STRESS METHOD[J]. Engineering Mechanics, 2020, 37(10): 209-217. DOI: 10.6052/j.issn.1000-4750.2019.12.0738

基于截面应力法的钢-UHPC组合板初裂荷载计算方法研究

CRACKING LOAD CALCULATION FOR STEEL-UHPC COMPOSITE SLABS BASED ON THE SECTION-STRESS METHOD

  • 摘要: 负弯矩作用下钢-超高性能混凝土(ultra-high-performance concrete,UHPC)组合板结构层的局部受拉开裂问题,是该类新型组合桥面板结构体系应用和发展的基础性研究课题。基于平截面假定和双折线UHPC拉伸本构模型,提出了能够描述UHPC结构层实际应力分布的截面应力法,用于计算这种新型结构在纯弯曲作用下的开裂荷载。通过2组4个模型试验并结合相关文献试验结果对所提出的计算方法进行了验证,研究结果表明:利用截面应力法能够较为准确的描述钢-UHPC组合板在纯弯曲作用下的开裂行为,计算给出的开裂荷载与实测值比值平均为0.95;UHPC的开裂强度仅取决于其自身材料特性,钢-UHPC组合板开裂荷载的提高不会影响UHPC层的开裂强度;UHPC层在可视裂缝出现时的应变硬化高度是组合效应及配筋对其约束的直观体现;减小纵筋保护层厚度或提高配筋率能够提高UHPC应变硬化区域高度,提高钢-UHPC组合板抗弯性能。

     

    Abstract: The local cracking problem of steel-UHPC (ultra-high-performance concrete) composite structures under negative bending moments is the basis of the application and development. Based on the UHPC tensile bilinear constitutive model and plane cross-section assumption, a section stress method is set up to describe the stress distribution of the steel-UHPC composite slabs and calculate the cracking load under a pure bending condition. The proposed method is verified by 4 specimens of 2 groups and the test results in the literature. The results indicate that the section-stress method can accurately describe the cracking behavior of steel-UHPC composite plates under pure bending and the average ratio of calculated to measured values is 0.95. The UHPC cracking strength is an intrinsic property dependent on the nature of the material itself and is not influenced by the steel-UHPC composite slab. The height of the UHPC strain hardening zone represents the combination effect and reinforcement constraint when visible cracks appear. By reducing the cover thickness or increasing the reinforcement ratio, the UHPC strain hardening height can be increased and the flexural behavior of the steel-UHPC composite slab can be improved.

     

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