The Effect Of Shaft Concrete In The Early-age Under Loads-Chemistry

Reinforced concrete shaft is important for mining engineering, which is mainly connects surface production systems and underground production systems. It will have a significant impact on safety production and the overall economic benefits. Due to the shaft wall during construction will be affected by freezing pressure, dead weight, permanent pressure, water seepage erosion and so on. The influence of such factors will make the shaft concrete damaged early, which easily leads to reduced endurance, shorten service life, and endanger the safety of wellbore. It's of great significant to research the damage rules of the early-age concrete under loading and chemical corrosion, which can improve the service life of the shaft concrete.Through the research, preparing strength grades for C50 and C60 concrete and designing a continuous loading device to study the stress level and load types(discontinuous load, continuous load), which will influence the 28 d compressive strength; Through the chemical corrosion test to study the types of corrosion solution(sodium chloride, sodium sulfate, and chloride-sulfate-flexure), the concentration of the solution which will influence the diffusion behavior of ion and the 28 d compressive strength of early-age concrete; Through the combination of the load and chemical corrosion to study the effect of the ion diffusion behavior and the 28 d compressive strength for early-age concrete.Test results show that under the early-age load(discontinuous load, continuous load), it can enhance the 28 d compressive strength of concrete within the certain load proportion. Chemical corrosion effects on early-age concrete can increases the corrosive ions content in concrete with the increase of the concentration gradient, the 28 d compressive strength of concrete are higher than which curing in the water, In mixed solution, the existence of chlorine salt can delay the sulfate attack of concrete. Under the combination of the load and chemical corrosion, it will accelerate the damage process of early-age shaft concrete with the two promote each other. Compared with the discontinuous load – chemical corrosion, continuous load- chemical corrosion will result in more serious impact.