Experimental Study On Mechanical Properties Of High Ductile Fiber Concrete Under Brine Erosion

The main characteristics of the Saline Lake brine are a large amount of corrosive salt ions,especially the sulfate ion and chloride ion,and the erosive ions and the concentration of each ion in the Saline Lake brine in all regions are different.In addition,the climate conditions in some areas are bad,there is extreme temperature difference,producing dry-wet cycle effect,affecting the life of the building,and the life of the building under the long-term soaking of the brine solution would also be affected.In this paper,the mechanical properties of high ductile fiber reinforced concrete under brine erosion were studied.The mechanical properties of drying and watering cycle and long soaking were studied under the erosion of different concentration of brine solution.It can provide a theoretical basis for the application of high ductility fiber concrete in engineering,and better guide the actual project.The main research and achievements in this paper are as follows:(1)The drying and watering cycle test of high ductility fiber concrete under three concentration brine solution has been carried out for 195 times.The experimental results show that the main erosion characteristics of the specimen is crystallization on the surface,and without obvious fibrous matrix shedding,and it has good integrity after erosion.There are multiple micro cracks on the failure surface of the specimen,and the deformation amount of failure is basically maintained at 2.5?3.5mm,which belongs to ductile failure.During the whole cycle,the quality of the specimens decreased and the maximum decreased to 91%.The higher concentration of ions in the solution,the greater influence of the strength of the specimen,the compressive strength of corrosion resistance coefficients decreased to less than 0.7,the solution of 3 specimens corrosion resistance coefficient decreased to 0.669,and the flexural strength of corrosion resistant coefficient decreased to 0.512.(2)High ductility fiber concrete is soaked in six concentrations of 360d.The results show that the erosion characteristics are mainly surface crystallization,and there is no obvious loss of fiber matrix.The effect of sulfate and chloride on high ductility fiber concrete is more serious than that of chlorine salt alone.When the concentration of sulfate ion is constant,the characteristic of surface erosion is more obvious with the increase of chloride content.When reachin,the 360d immersion cycle,the quality of HDFC specimens increased.There are many fine cracks on the surface of specimens under six kinds of solution erosion,which is ductile failure.The flexural strength and compressive strength decreased after the test,of which the flexural strength decreased most and the strength decreased by 18.8%in 5 solution,and the compressive strength decreased by 15.4%in the 6 solution.(3)Under the two test conditions,the erosion characteristics of the specimen have similar characteristics.Through the contrast of the strength after erosion,it is found that the flexural strength and the compressive strength of the specimens are most affected by the drying and watering cycle.