Mechanical Properties And Microscopic Study Of Graphene Oxide-reinforced Fiber Cement-based Composites

With cement mortar as the matrix,polypropylene fiber is added to enhance the flexural strength of cement mortar,so as to prevent cracking.At the same time,nano-material go is added to improve the compressive strength of cement mortar,so as to make up for the brittleness.Nano-indentation technology was used to study the effect of go on the improvement of the micromechanical properties of cement-based materials,and the modification mechanism and reasons were studied in combination with the microscopic analysis.The main research contents are as follows:?1?polypropylene fiber significantly improves the flexural strength of cement mortar,and the flexural strength increases with the increase of the content of polypropylene fiber.When the content of polypropylene fiber is 2%,the enhancement effect is the best,which is 33.3%higher than that without the content of polypropylene fiber.Go significantly increased the compressive strength of cement mortar.With the increase of go content,the compressive strength gradually increased and became saturated.The compressive strength of go cement mortar with 0.04%content increased by 43.6%compared with that without addition.?2?when polypropylene fiber and go were added at the same time,the flexural strength and compressive strength of cement mortar were improved.When the content of polypropylene fiber was 2%and the content of go was 0.04%,the flexural strength of cement mortar was 13.1mpa and the compressive strength was 66.6mpa,which were 36.5%and 36.2%higher than that of the blank control group,respectively.?3?using the nano indentation meter test graphene oxide cement net pulp hardness and elastic modulus,the results showed with the increase of graphene oxide,hardness and elastic modulus increased,mainly oxidation graphene to improve the cement hydration process and hydration products of low density reduce calcium silicate gel,high density calcium silicate gel content,promote hydration particles hydration results.?4?the continuous stiffness method was used to test the effect of strain rate on the hardness and elastic modulus of the cement slurry.The results showed that thechange of strain rate had little effect on the hardness of the cement slurry.Within the range of strain rate from 0.01s^-11 to 0.5s^-1,the elastic modulus of the same amount of go cement slurry increased with the increase of the strain rate,and the elastic modulus at 0.5s^-11 increased by 46%compared with that at 0.01s^-1.