Experimental Study Of Constitutive Relation Of Concrete Under The Loads-Chemical Corrosion

Concrete will be affected by the role of chemical corrosion in some environment,and concrete internal produce microfracture under heavy load,used to accelerate chemical corrosion and damage more serious in engineering structures.In view of this,the experiment studied the effect of load and chemical corrosion on the stress-strain relationship of concrete,so that,provided a scientific basis for the design and safety of concrete structure bearing capacity.A total 121 specimens of the stress-strain curves of concrete under the load,chemical corrosion,or the load-sulfate corrosion,which were measured under uniaxial compression by the presses of additionally rigid component in all age.In addition,Using SEM and XRD microscopic test technology,analyzes the sulfate corrosion of concrete internal structure evolution and the form of the corrosion product.Meanwhile,reveals the damage evolution process under the action of sulfate concrete mechanics performance from micro perspective.Under a single loading history,which is no significant for changing the stress-strain curves of concrete when the ratio of load is less than 30%,however,when the ratio of load is 40%,loads is obviously damaged to concrete,the peak stress decreases,meanwhile,the concrete ductility is increased.Under the continuous load,the load level is favorable to the increase of concrete peak stress before 30%,but the peak stress decreases when the load ratio is 40%.Under the effect of sulfate corrosion,before 90 days,sulfate corrosion improves the peak stress and elasticity modulus of concrete,and the peak strain is decreased.The peak stress and elasticity modulus will decrease when the corrosion 120 days.The low level of sustained load is capable of inhibition sulfate attack on concrete,at the same time,the damage of concrete is more significant with the increase of the corrosion solution concentration.120 days,the sustained load-sulfate etching effect is more seriously damaged to concrete than single loading history-sulfate corrosion under the same ratio of load.And the curves were fitted very well with the sectional form of equations.The relationship between the characteristic value of stress-strain curve and corrosion time is established.