| Concrete is applied in current building structure extensively as a building material,but as its tensile strength is low,limit elongation is small and poor durability,people usually adopt new technology to further process it and make its performance more superior in application.At present,most of researches on fiber concrete stop at chemical synthetic fiber concrete and mineral fiber concrete.These two kinds of fiber concrete can overcome the shortages of traditional concrete,but the cost is relatively high.Natural plant fiber has the advantages of light material,wide source of raw material,low price,recyclable with natural decomposition as well as no pollution to environment,which can be taken as the reinforced material of cementitious material to replace chemical synthetic fiber and mineral fiber.It is with practical significance to study and promote plant fiber concrete.Main work of this paper includes following parts:This paper first proposes the preprocessing method of alkali liquor for jute fiber based on the physical and mechanical properties as well as chemical components of jute fiber.The optimum length size and addition ratio of jute fiber have been confirmed through orthogonal test.Experimental researches on cube compressive strength,splitting tensile strength,rupture strength,gas content and freeze-thaw test have been made for jute fiber concrete specimen.The mechanism of jute fiber was analyzed by scanning electron microscopy(SEM).Numerical simulation analysis has been made for medium section bar column products of jute fiber reinforced concrete through ANSYS finite element software.Through experimental research and analysis: After alkali treatment,the bonding and supporting effect of jute fiber and cement slurry can be effectively improved.The orthogonal test is used to prepare fiber concrete with jute fiber after treatment.The optimum mix ratio is A1B2C2.The uniaxial compression strength is increased by12.61%,Splitting strength increased by 9.52%,the mass loss rate of freeze-thaw cycle test and relative dynamic elastic modulus have been improved in varying degrees.With scanning electron microscope(SEM),the operation mechanism of jute fiber to improve concrete performance is analyzed from microcosmic perspective,and the fiber is reinforced,toughened and cracked.Jute fiber presents uniform and random distribution in concrete,it can effectively fill the micro cracks between concrete,reduce the porosity of the concrete structure to enhance the density,delay and prevent the initiation and expansion of the cracks. |
