摘要
目的为改善再生混凝土不均匀性产生的不利影响,实现再生粗骨料利用,进行了配筋钢管再生混凝土承载力的计算方法研究。方法基于统一理论思想,充分考虑钢管和钢筋对核心再生混凝土的双重约束作用,对既有核心再生混凝土本构模型中的套箍系数等指标进行修正,得到适合配筋钢管再生混凝土的非线性数值模拟模型,并采用现有试验数据验证模型的可靠性,以修正后的套箍系数为参数对不同钢管壁厚、纵筋直径和混凝土强度等级正交得到的90根模型试件进行参数化分析。结果随着混凝土强度和钢管壁厚的增加,组合抗压强度对应的荷载值和峰值荷载后的塑性变形能力均呈现增加趋势,而纵筋直径的增加对此影响不大。基于此,以现有T/CECS625-2019规程中钢管再生混凝土短柱承载力公式为参考,提出基于统一理论思想的R-RACFST(reinforced and recycled aggregate concrete-filled steel tube)短柱承载力计算公式。为验证该计算公式的可靠性,对100组既有试验和模型试件的试验值和公式计算值进行对比分析。结果表明,直接采用CECS408-2015中的配筋钢管混凝土公式得到的试验值与计算值之比的平均值为0.95,标准偏差为0.05,采用本文推荐的配筋钢管再生混凝土短柱承载力公式试验值与计算值之比的平均值为1.11,标准偏差为0.06。结论本文提出的配筋钢管再生混凝土短柱承载力公式安全可靠,符合工程实际。
Objectives This study aims to mitigate the adverse effects caused by the inhomogeneity of recycled aggregate concrete and to promote full utilization of recycled coarse aggregate by developing a calculation method for the bearing capacity of reinforced recycled aggregate concrete-filled steel tubes(RRACFST).Methods Based on the unified theory approach,the study fully considered the dual restraining effects of the steel tubes and steel reinforcement on the core recycled concrete.It modified parameters such as the confinement coefficient in existing concrete constitutive models to derive a nonlinear numerical simulation model suitable for R-RACFST.After verifying the model’s reliability with existing experimental data,a parameterized analysis was conducted on 90 model specimens obtained through orthogonal design considering different steel tube wall thicknesses,longitudinal reinforcement diameters,and concrete strength grades,using the corrected hoop coefficient as a parameter.Results When other parameters remained unchanged,increasing the concrete strength and steel tube wall thickness led to increased ultimate compressive strength and enhanced post-peak plastic deformation capacity,whereas increasing the diameter of the longitudinal reinforcement had minimal effect.Based on these findings and considering the influence of the three parameters on bearing capacity,the study referenced the existing T/CECS625-2019 code’s formula for short-column bearing capacity of recycled aggregate concrete-filled steel tubes,and proposed a new formula for calculating R-RACFST short-column bearing capacity based on the unified theory.To validate the reliability of the proposed formula,a comparative analysis was performed between experimental and calculated values for 100 sets of existing tests and model specimens.Results showed that directly using the reinforced concrete-filled steel tube formula from CECS408-2015 yielded an average ratio of 0.95 with a standard deviation of 0.05 between experimental and calculated values.In contrast,the proposed R-RACFST formula resulted in an average ratio of 1.11 with a standard deviation of 0.06,indicating better agreement.Conclusions The formula proposed in this study for R-RACFST short-column bearing capacity is safe,reliable,and applicable to engineering practice.
作者
阿里甫江·夏木西
邵金兰
史露江
Xiamuxi Alifujiang;Shao Jinlan;Shi Lujiang(College of Civil Engineering and Architecture,Xinjiang University,Urumqi 830017,Xinjiang,China;Changzhou Construction Science Research Institute Group Co.,Ltd.,Changzhou 213000,Jiangsu,China)
出处
《河南理工大学学报(自然科学版)》
北大核心
2025年第4期179-187,共9页
Journal of Henan Polytechnic University(Natural Science)
基金
国家自然科学基金资助项目(51968068)。
关键词
配筋钢管再生混凝土
套箍系数
承载力
有限元分析
reinforced recycled aggregate concrete-filled steel tubes
confinement coefficient
bearing capacity
finite element analysis
