冻融环境下玄武岩纤维泡沫混凝土的损伤特性  

Damage characteristics of basalt fiber foamed concrete in freeze-thaw environment

作　　者：周兰庭[1,2] 王浩 陈波[1,2] 高志涵 周程涛[1,2] Zhou Lanting;Wang Hao;Chen Bo;Gao Zhihan;Zhou Chengtao(College of Water-conservancy and Hydropower,Hohai University,Nanjing 210098,China;State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学水利水电学院,南京210098 [2]河海大学水文水资源与水利工程科学国家重点实验室,南京210098

出　　处：《东南大学学报（自然科学版）》2024年第6期1438-1446,共9页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51209078,51739003)。

摘　　要：为探究冻融环境下玄武岩纤维泡沫混凝土的损伤特性,对纤维体积分数分别为0、0.15%、0.30%、0.45%的4种泡沫混凝土分别进行了0、20、40、60、80次冻融循环试验.通过单轴压缩-声发射联合装置,研究了泡沫混.凝土的损伤演化规律及其破裂类型和裂缝发展特征.结果表明:泡沫混凝土的受压过程存在明显的阶段性;冻融循环劣化了泡沫混凝土的力学性能,经过80次冻融循环,纤维体积分数为0、0.15%、0.30%、0.45%的4种试件的峰值抗压强度分别降低65.0%、54.4%、24.4%、36.1%;冻融循环可降低声发射活跃度,促进泡沫混凝土张拉裂纹向剪切裂纹的转变,加速混凝土内部孔隙扩展及裂缝开展;玄武岩纤维的掺入减少了泡沫混凝土内部损伤,促进张拉裂纹的产生,有效抑制大尺度裂纹的发展,显著提升力学性能.To investigate the damage characteristics of basalt fiber foamed concrete in freeze-thaw environment,four kinds of foam concrete with fiber volume fractions of 0,0.15%,0.30%and 0.45%were subjected to freeze-thaw cycle tests for 0,20,40,60 and 80 times,respectively.The damage evolution law,fracture types and crack development characteristics of foamed concrete were studied by the uniaxial compression-acoustic emission combined device.The results show that there are obvious stages in the compression process of foam concrete.Freeze-thaw cycles deteriorate the mechanical properties of foamed concrete.After 80 freeze-thaw cycles,the peak compressive strengths of four specimens with the fiber volume fractions of 0,0.15%,0.30%and 0.45%decrease by 65.0%,54.4%,24.4%and 36.1%,respectively.Freeze-thaw cycle can reduce the activity of acoustic emission,promote the transformation of tensile cracks to shear cracks in foam concrete,and accelerate the expansion of internal pores and cracks in concrete.The addition of basalt fiber can reduce the internal damage of foamed concrete,promote the generation of tensile cracks,effectively inhibit the development of large-scale cracks,and improve mechanical properties.

关 键 词：冻融循环 泡沫混凝土 玄武岩纤维 声发射 单轴压缩 

分 类 号：TU528.2[建筑科学—建筑技术科学]