Study On The Relationship Between Strength And Durability Of Concrete

Theoretically,the higher the strength of concrete is,the better the durability of concrete will be.However,in practical engineering applications,high-strength concrete does not necessarily have high durability,and middle-and-low strength concrete can also exhibit good durability.As a result,the relationship between the strength and durability of concrete becomes blurred.In order to explore the law between the strength and durability of concrete,this paper uses the method of “first loading and then testing” to simulate the durability test of concrete in service,which means that the specimens of different concrete strength grades are loaded first,and then the freeze-resistance,carbonation resistance,chemical resistance and other durability tests are performed on the loaded specimens.The relationship between strength and durability of concrete is studied.The results show that:(1)When the stress level(ratio between stress and strength)is 0%,that is,under the condition of pure material(the current method of testing durability),the change rule between the strength and durability of concrete conforms to the law of "the higher the strength,the higher the durability,the concrete strength grade determines the durability.(2)When the stress level is 40 to 60%,that is,in service,the durability of concrete of high,medium and low strength grades is approximately the same,and the inherent law of strength and durability is different from that of under the condition of pure materials;at this point,the strength and durability are not closely related.and stress levels play a key role.(3)The durability of the concrete under service is lower than that of under the condition of pure material.It is inaccurate to use the durability results of concrete under the condition of pure materials to guide practical engineering applications,and to exaggerate the durability of concrete under service conditions.(4)The higher the stress level of concrete,the faster the durability will decline.Therefore,for the durability design of concrete structures under complex environments,The durability of the concrete structures can be improved by increasing the excess strength of the concrete structures or reducing the actual stress level of the concrete structures.