关键词: 玄武岩纤维混凝土;应力-应变;峰值应力;微观结构;分形维数

Abstract: In order to explore the effect of fiber content on the properties of basalt fiber reinforced concrete macro and micro , the digital image correlation method and the microscopic pore structure analyzer were used to test different fiber content of the concrete specimen .Based on data regression , the relationship between the fiber content and the average peak stress was established .And the expression of the ascent stage of stress-strain curve under uniaxial compression was also set up .Combine with microstructure , the formula of the average peak stress and the air content , the average bubble chord length , the hole spacing , the specific surface area was given .At the same time , the fractal dimension was used to quantitatively describe the relationship between microstructure and compressive strength and elastic modulus of basalt fiber reinforced concrete .The results show that the basalt fiber can improve the average peak stress and peak strain of concrete , but cannot change the ascent stage of stress-strain curve obviously .And the addition of basalt fiber not only reduce the internal defects of concrete , but reduce the gas content and the average chord length of concrete , also make the internal pore structure of concrete be optimized and the pore distribution is uniform , besides the compressive strength is improved and the secant modulus decreases .

Key words: basalt fiber reinforced concrete;stress-strain;peak strain;microstructure;fractal dimension