Study On The Axial Compression Properties And The Corrosion Resistance Of Chlorine Salts In Damaged Concrete Reinforced By HDC

In order to avoid economic loss and waste of resources,it is particularly important to strengthen structure in a reasonable way.The application of high ductile concrete(HDC)in strengthening damaged concrete structures will have a great influence on the field of concrete strengthening.The strengthening method makes use of its own good fluidity,can be cast into any shape and good adhesion between the reinforced layer and the surface layer of the original member,so that the reinforced layer and the original member can work together in coordination with each other.In addition to the damage to the concrete structure caused by earthquakes or other external forces,it also be eroded by chloride ions brought in from sea water or other factors.In order to make the strengthening method widely used in works practice,this article has carried out two parts of research.The first part is the experimental study on axial compression of damaged concrete short column strengthened by HDC.In the second part,relevant experimental stucdies were carried out on the mechanical properties of HDC under the condition of chloride erosion,and its mechanical properties were analyzed after drying and wetting cycles with different concentrations of chloride salt solutionThrough the axial compression test of twenty-two strengthening damaged concrete short columns with HDC(After reinforcement,13 sizes are 240mm × 240mm × 1 000mm and 9 sizes are 280mm × 280mm × 1 200mm.),the influence of HDC on the bearing capacity and deformation capacity of damaged concrete was studied.The experimental results showed that:using good interfacial adhesion properties of HDC strengthening damaged reinforced concrete short columns,can increase the bearing capacity and ductility of the members.The stress-strain constitutive equation of HDC restrained damaged concrete is obtained through experimental analysis and derivation.It is found that there is a good agreement between the calculated value and the experimental value by comparing the calculated value of peak stress with the experimental value,and the bearing capacity formula of HDC restrained damaged concrete is given.The dry and wet cycle tests of HDC and ordinary concrete specimens were carried out under three concentrations of chlorine salts,and a total of two hundred and forty cycles were conducted.By contrast,the surface of the HDC test specimen appears fine cracks at the time of destruction.There is no phenomenon of concrete shedding in the process of soaking and testing the strength.However,the ordinary concrete specimen sloughed off in large chunks and its ductility is very poor in the test process.The higher the concentration is,the sooner the salinization appears on the surface of the specimen.With the increase of concentration,the strength and ductility of HDC specimens decrease slightly.But they are generally superior to the ordinary concrete specimen under the same conditions,the results show that the HDC specimen is more resistant to chloride corrosion than the ordinary concrete specimen.In this article,the axial compression property and chlorine salt erosion resistance of HDC strengthening damaged concrete short columns are studied,some conclusions are obtained,which provide reference value for the application of practical works.