Based on the experimental study of the internal pore structure and mechanical properties of basalt fiber concrete under different temperature damage.The pore structure and mechanical properties of basalt fiber concrete at 50 ℃,100 ℃,200 ℃ and 300 ℃ were measured by self heating nuclear magnetic resonance(NMR)and electro-hydraulic servo press.The microstructure of the specimen after high temperature was observed by SEM.The results show that the T2 spectrum of the specimen has obvious three peak characteristics and the increase of temperature increases the T2 spectrum peak and porosity.When the temperature gradually rises from 50 ℃ to 300 ℃,the average porosity of the specimen increases from 2.63％to 4.16％,and the fractal dimension of the pore structure decreases accordingly,and the variation range of DNMR(min)is significantly lower than DNMR(max).The complexity of macropores is more susceptible to the temperature under thermal damage.Compared with the strength of the specimen at 50 ℃,the uniaxial compressive strength of the coal samples at 100 ℃,200 ℃ and 300 ℃ decreases by 4.81％,16.53％and 24.90％,and the tensile strength decreases by 8.51％,25.53％and 42.55％.The increase of temperature increases the porosity of the specimen,reduces the resistance to external load and reduces the integrity.SEM test results show that there are a lot of cracks in the specimen after high temperature,and with the increase of temperature,the width and number of cracks in the specimen become larger.
关键词
玄武岩纤维混凝土/核磁共振/T2光谱/孔隙率/分形维数/力学性能/微观结构
Key words
basalt fiber concrete/nuclear magnetic resonance/T2 spectrum/porosity/fractal dimension/mechanical properties/microstructure
维普
万方数据