两跨连续钢-再生混凝土组合板长期性能与预测

Long-Term Behavior and Design Procedure of Two-Span Steel-Recycled Aggregate Concrete Continuous Composite Slabs

为量化掺入再生粗骨料对两跨连续钢-再生混凝土组合板长期性能的影响并提出相应的设计方法,综合考虑混凝土非均匀收缩、徐变及开裂的影响,采用ABAQUS软件建立组合板长期性能有限元模型,并利用现有长期性能试验数据验证有限元模型的可靠性;进行有限元参数分析,量化再生粗骨料取代率等因素对两跨连续钢-再生混凝土组合板长期性能的影响;进而提出两跨连续钢-再生混凝土组合板长期性能设计方法,并对设计方法的可靠性进行评价。研究结果表明:所建立的有限元模型可有效预测两跨连续钢-再生混凝土组合板的长期性能,预测值与试验值相差在10%以内;再生粗骨料取代率对两跨连续组合板长期性能影响显著,再生粗骨料取代率分别取50%和100%时,组合板长期中支座负弯矩与跨中挠度分别增加7%与12%、21%与42%;考虑混凝土非均匀收缩变形影响的长期性能设计方法可有效预测两跨连续组合板的长期负弯矩作用范围、中支座负弯矩、裂缝宽度及跨中挠度,预测值与试验值最大相差15.3%。

To quantify the impact of recycled coarse aggregate(RCA)incorporation to the long-term behavior of double-span steel-recycled aggregate concrete(RAC)continuous composite slabs and to propose the corresponding design procedures,a finite element model(FEM)for the long-term behavior of the composite slabs was established by ABAQUS based on age-adjusted effective modulus method(AEMM)and considering the combined effects of non-uniform shrinkage,creep and cracking of concrete;the reliability of the FEM was benchmarked against the existing long-term performance test data;a parametric analysis was conducted to quantify the influence of RCA replacement ratio and other factors on the long-term behavior of double-span continuous steel-RAC composite slabs;furthermore,a design method for the long-term performance of double-span continuous steel-RAC composite slabs was proposed,and the reliability of the design method was evaluated.The results show that the FEM established in this paper can effectively predict the long-term performance of double-span continuous steel-RAC composite slabs,and the maximum difference between the predicted value and the experimental value was within 10%;the long-term behavior of double-span continuous composite slabs was significantly affected by the replacement ratio of recycled coarse aggregate,7%and 12%increments in the hogging moment and 21%and 42%increments in the mid-span deflection were obtained for r ratios of 50%and 100%,respectively;the long-term design method considering the influence of non-uniform shrinkage deformation of concrete can effectively predict the range of long-term hogging moment zones,the hogging moment over the interior support,crack width and the mid-span deflection of double-span continuous composite slabs,with the maximum error between the predicted and test results of 15.3%.