Study On The Fluidity And Mechanical Properties Of Steel Fiber Coral Mortar Under The Action Of Magnetic Field

Fluidity is an important index to measure the working performance of fresh mortar,which has a great influence on the transportation and placing process of concrete.And the mechanical properties of mortar after hardening are an important basis to ensure the normal working of the components.The mechanical properties of mortar specimens can be improved by incorporating steel fibers in mortar,but the incorporation of steel fibers has a certain influence on the fluidity of fresh mortar,and due to the disordered distribution of steel fibers in mortar,some steel fibers do not improve the strength of mortar very well.In view of the above problems,this paper improves the fluidity and mechanical properties of fresh steel fiber mortar based on the principle of magnetic field oriented steel fiber.In this thesis,the method is introduced,the fluidity experiment and the mortar compressive and flexural test are carried out,and the fluidity and mechanical properties are compared and analyzed by using two materials,coral mortar and ordinary mortar.And based on modern electromagnetic theory,a magnetic field program was written in the extended discrete element software(EDEM)to numerically simulate the flow and mechanical properties of mortar.The details are as follows:(1)By adjusting the magnitude and direction of the magnetic field,the fluidity change law of freshly mixed steel fiber mortar under the action of different magnetic fields was studied.Subsequently,numerical simulation was carried out in EDEM and compared with the experiment.(2)The relationship between the magnetic field application time and the orientation of steel fibers at different magnetic flux densities was quantitatively investigated by numerical simulations,and the effects of the magnetic flux density,mortar resistance,and the initial position of steel fibers on the orientation of steel fibers were analyzed.(3)Taking the type of sand and the magnetic flux density applied in the pouring process as variables,the flexural and compressive tests of mortar were carried out.The flexural and compressive strength of the two materials were compared,and the influence of magnetic flux density on the flexural and compressive strength of the two materials was studied.Based on the bonding model in EDEM,the flexural and compressive tests of the two mortars were simulated and the results were compared.