振动搅拌工艺优化下C50混凝土力学性能研究  

Research on the Mechanical Properties of C50 Concrete under the Optimization of Vibration Mixing Process

作　　者：白峰 王馨日 杨飞 段坤辰 BAI Feng;WANG Xin-ri;YANG Fei;DUAN Kun-chen(CCCC Central South Engineering Bureau Co.Ltd.,Changsha 410000,China;College of Civil and Transportation Engineering,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]中交中南工程局有限公司,长沙市410000 [2]广东工业大学土木与交通工程学院,广州市510006

出　　处：《公路》2024年第9期300-306,共7页Highway

基　　金：国家自然科学基金项目,项目编号12072079。

摘　　要：为探究冲击荷载作用下振动搅拌(VM)和常规搅拌(CM)对普通C50混凝土力学性能的影响,采用分离式霍普金森压杆试验装置(SHPB)对不同搅拌方式(VM110 s、120 s、130 s以及CM180 s)的C50混凝土进行动态单轴压缩,分析振动搅拌时间对试件的平均应变率、峰值应力、冲击韧性及能量耗散的影响规律。结果表明:振动搅拌110 s、120 s、130 s的混凝土静态抗压性能相较于常规搅拌180 s分别提升7.2%、22%、3.5%,在振动搅拌120 s获得的提升最大,搅拌方式和时间对其强度存在较大影响;相同应变率时,振动搅拌下混凝土动态压缩的DIF值均比常规搅拌下的混凝土大,峰值应力明显高于常规搅拌,搅拌方式和时间对其具有明显影响,在VM120 s时动态压缩应变率效应最为显著;相近的应变率下,VM110、VM120、VM130时的冲击韧性均高于CM180,且不同振动搅拌时间对其影响较为微小,振动搅拌可以显著提高材料的抗冲击性能。通过SEM成像,观察到振动搅拌与常规搅拌混凝土破坏后的微观形貌,发现振动搅拌下的混凝土呈现更高水化程度,相较于常规搅拌混凝土,界面强度得到了有效改善。In order to explore the impact of vibration mixing(VM)and conventional mixing(CM)on the mechanical properties of standard C5o concrete under impact loading,dynamic uniaxial compression tests are conducted on C50 concrete specimens prepared using different mixing methods(VM110 s,120 s,130 s,and CM180 s)utilizing the split Hopkinson pressure bar test apparatus(SHPB).The influence of vibration mixing duration on the average strain rate,peak stress,impact toughness,and energy dissipation of the specimens is examined.The findings indicate that the static compressive characteristics of concrete subjected to vibration mixing for 110 s,120 s,and 130 s are respectively 7.2%,22%,and 3.5%higher than those of conventionally mixed concrete for 180 s.The greatest enhancement is observed with a vibration mixing duration of 120 s,highlighting the significant impact of mixing method and duration on concrete strength.Under identical strain rates,the dynamic impact resistance of concrete subjected to vibration mixing surpasses that of conventionally mixed concrete,with notably higher peak stress values.The mixing method and duration exert discernible influences on this outcome,with the dynamic compression strain rate effect most pronounced at VM12o s.At comparable strain rates,the impact toughness of VM110 s,120 s,and 130 s exceeds that of CM180,with minimal variation attributable to different vibration mixing duration.Vibration mixing substantially enhances the material's impact resistance.SEM imaging reveals distinct micro-structural characteristics of the damaged concrete following vibration mixing and conventional mixing.Notably,concrete subjected to vibration mixing exhibits enhanced hydration levels and improved interfacial strength compared to conventionally mixed concrete.

关 键 词：混凝土 振动搅拌 动态力学性能 应变率效应 微观形貌 

分 类 号：U414.18[交通运输工程—道路与铁道工程] TU528[建筑科学—建筑技术科学]