两跨连续钢-再生混凝土组合梁长期性能研究

Long-Term Performance of Two-Span Continuous Steel-Recycled Concrete Composite Beams

为研究再生粗骨料的掺入对两跨连续钢-混凝土组合梁长期性能的影响,考虑混凝土收缩徐变等影响,基于ABAQUS软件建立组合梁长期性能有限元模型,采用现有的3组两跨连续钢-混凝土组合梁长期试验数据验证模拟的可靠性。在此基础上,对两跨连续钢-再生混凝土组合梁进行参数分析,量化各因素对其长期性能的影响。研究结果表明:采用龄期调整的有效模量法考虑构件的长期持荷效应、采用温度场考虑混凝土的收缩效应,所建立的两跨连续组合梁跨中挠度的有限元结果与试验结果最大相差11.7%、中支座负弯矩有限元结果与试验结果相差3.77%;与普通混凝土试件相比,再生粗骨料取代率为50%和100%时,两跨连续钢-再生混凝土组合梁长期挠度增加5.52%~9.72%和12.98%~20.39%;与采用钢筋混凝土楼板(承受均匀收缩徐变影响)的试件相比,采用开口型和闭口型组合楼板的试件(承受非均匀收缩徐变影响)长期挠度与瞬时挠度的比值减少8.04%~19.56%,故应针对不同的楼板类型选用不同的收缩徐变模型。

To study the influence of recycled coarse aggregate(RCA)on the long-term performance of two-span continuous steel-concrete composite beams,a nonlinear finite element model(FEM)was established based on ABAQUS software,considering the combined effects of concrete shrinkage and creep.The reliability of the simulation was verified by three group long-term test results of two-span continuous steel-concrete composite beams.Further,the parameters of two-span continuous steel-recycled concrete composite beams were analyzed,and the influence of each parameter on their long-term performance was quantified.The results showed that the maximum difference in the mid-span deflection of two-span composite beams between the FE results and the experimental results was 11.7%,and a 3.77%difference between the FE results of the negative bending moment of the middle bearing and the experimental results was obtained.The results show that when the RCA replacement ratio is 50%and 100%,the long-term deflection of the two-span continuous steel-concrete composite beam increases by 5.52%~9.72%and 12.98%~20.39%.When the specimens using reinforced concrete slab(under the influence of uniform shrinkage and creep)are replaced with open-end and closed-end composite slab(under the influence of non-uniform shrinkage and creep),the ratio of long-term deflection to instantaneous deflection is reduced by 8.04%~19.56%.Different shrinkage creep model should be selected for different floor slab types.