| 摘要: |
| 为研究玄武岩纤维-矿渣粉-粉煤灰混凝土（BSFC）的抗冻性能，进行了单轴抗压强度试验、劈裂抗拉试验、超声波检测试验和孔结构表征试验，分析了冻融前后BSFC的质量损失率、相对波速、相对抗压强度、相对劈裂抗拉强度的变化规律以及细观结构特征.同时，运用损伤力学对BSFC的冻融损伤进行多指标评价；采用分形维数计算BSFC的气孔结构分布分形维数，拟合得到玄武岩纤维的贡献率公式，建立了基于气孔结构分布分形维数和玄武岩纤维贡献率的冻融损伤模型.结果表明：随着冻融循环次数的增加，BSFC的质量损失率增大，纵波波速、抗压强度和劈裂抗拉强度下降；BSFC的孔结构劣化，大孔径孔数量增多，气孔结构分布分形维数降低；在相同冻融次数下，玄武岩纤维掺量为0.18%时BSFC的抗冻性好；BSFC的冻融损伤与气孔分布分形维数、玄武岩纤维贡献率之间回归效果显著，可以预测经历冻融循环后BSFC的损伤劣化. |
| 关键词: 玄武岩纤维-矿渣粉-粉煤灰混凝土 压拉强度 纵波波速 分形维数 气孔结构 损伤模型 |
| DOI：10.3969/j.issn.1007-9629.2021.06.007 |
| 分类号:TU528 |
| 基金项目:安徽省高校协同创新项目（GXXT-2019-005） |
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| Frost Resistance and Damage Model of BSFC under Freeze-Thaw Cycles |
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WU Qianyun1,2, MA Qinyong1,2
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1.School of Civil Engineering and Architecture， Anhui University of Science and Technology， Huainan 232001， China;2.Engineering Research Center of Underground Mine Construction， Ministry of Education， Anhui University of Science and Technology， Huainan 232001， China
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| Abstract: |
| To study the frost resistance of basalt fiber-slag powder-fly ash concrete （BSFC）， uniaxial compressive strength test， split tensile test， ultrasonic testing test and pore structure characterization test were carried out. The change rules of mass loss rate， relative wave velocity， relative compressive strength， relative splitting tensile strength and mesostructure characteristics of BSFC before and after freeze-thaw cycle were analyzed. The damage development was evaluated by multi-index of BSFC based on damage mechanical theory. The fractal dimension of distribution of air-void structure of the BSFC was calculated using the fractal theory. The contribution rate formula of basalt fiber under different number of freeze-thaw cycle was obtained by fitting the experimental data. Finally， the freeze-thaw damage model was established based on multiple factors such as fractal dimension and basalt fiber contribution. The results show that with the increase of the number of freeze-thaw cycle， the mass loss rate increases， but the P-wave velocity， compressive strength， and splitting tensile strength decrease； the air-void structure deteriorates and the number of harmful voids increases， and the fractal dimension of the pore structure distribution decreases. Under the same number of freeze-thaw cycle， compared with other fiber dosage， BSFC mixed with basalt fiber of 0.18% has the best frost resistance. The regression effect of freeze-thaw damage and fractal dimension of air-void structure and basalt fiber contribution rate is significant， which can predict the damage deterioration of BSFC after freeze-thaw cycles. |
| Key words: basalt fiber-slag powder-fly ash concrete（BSFC） compressive and tensile strength P-wave velocity fractal dimension air-void structure damage model |
