骨料粒径对模型骨料混凝土剪切性能影响研究  

Effect of Aggregate Particle Size on Shear Performance of Modeled Aggregate Concrete

作　　者：王之鑫 孙畅 刘琼 WANG Zhixin;SUN Chang;LIU Qiong(School of Environment and Architecture,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学环境与建筑学院,上海200093

出　　处：《粉煤灰综合利用》2025年第1期7-12,23,共7页Fly Ash Comprehensive Utilization

基　　金：国家自然科学基金(51808338)。

摘　　要：通过对17、23、30 mm三种不同骨料粒径的模型骨料混凝土试件进行剪切试验,研究骨料粒径对模型骨料混凝土剪切性能及裂缝开展规律的影响,揭示模型骨料混凝土剪力传递机理,分析不同骨料粒径对混凝土剪切性能影响。结果表明:随着骨料粒径由17 mm增大至30 mm,峰值荷载逐渐增大,增长速度逐渐下降;峰值荷载对应的剪切滑移增大,增长速度逐渐上升。三种骨料粒径的模型骨料混凝土试件荷载-位移曲线均近似呈现上升、下降及回升或平稳三个阶段。裂缝宽度-滑移曲线的增长趋势与骨料断裂情况有关。三种不同骨料粒径模型骨料混凝土试件的骨料断裂情况及裂缝发展呈现不同特征,应变集中区分布与骨料断裂情况有关。偏小粒径,骨料发生断裂,骨料裂缝间机械咬合与摩擦作用传递剪力;偏大粒径,骨料保持完整,骨料与砂浆间机械咬合与摩擦作用传递剪力;中等粒径,表现出过渡性破坏模式;不同粒径试件呈现差异化剪力传递特征。Through shear tests on modeled aggregate concrete specimens with three distinct aggregate particle sizes of 17,23,and 30 mm,this study investigates the influence of aggregate particle size on the shear performance and crack development behavior of modeled aggregate concrete.The study clarifies the shear transfer mechanism in modeled aggregate concrete and analyzes different aggregate particle sizes affect concrete's shear performance.According to the results,as the aggregate size increases from 17 mm to 30 mm,the peak load increases gradually and the growth rate decreases gradually.Correspondingly,the shear slip at peak load also increases,with its growth rate accelerating.The Load-displacement curves for specimens with the three aggregate particle sizes show approximately three stages:an initial rise,followed by a decline,and then either a secondary rise or stabilization.The fracture condition of the aggregate influences the trend of crack width-slip curves.Specimens with different aggregate particle sizes display distinct characteristics in terms of aggregate fracture and crack propagation,with strain concentration areas correlating closely with aggregate fracture patterns.Specifically,smaller particles tend to fracture,leading to mechanical interlock and friction between cracks to transfer shear forces;larger particles remain intact,relying on mechanical interlock and friction between the aggregate and mortar to transfer shear forces;medium-sized particles exhibit transitional failure modes.Overall,specimens with varying particle sizes demonstrate distinct shear force transfer characteristics.

关 键 词：模型骨料混凝土 骨料粒径 裂缝发展 剪切性能 

分 类 号：TU528[建筑科学—建筑技术科学]