Study On The Performance Of Early-age Concrete Under The Effect Of Loads And Corrosion

Concrete as a structural material is more and more widely used in the construction industry.In the actual construction process,it may be under weight and loads if not reached the design strength,or be influenced by external environment or non-artificial factors under artificial.It will be damage to the early concrete,and affect the life of the whole structure.Therefore,it is of significance to study the effect of load and sulphate erosion on concrete performance in early age.To prepare the strength of C35 and C45 of concrete,It is studied the effect of load level,discontinuous and continuous load on the concrete of early age.To study the effects of different concentrations and immersion methods on the strength of concrete and the rule of sulfate ions by soaking the early concrete in sodium sulfate solution.And to analyse the characteristics and morphology of the erosion products by using SEM and XRD method Through the combination with the load and sodium sulfate erosion,it is also studied the effect on the strength of concrete and the rule of sulfate ions.The results show that the concrete exert 15%~35% discontinuous or continuous load,the compressive strength of concrete increases first and then decreases with the increase of loading level at 30d~120d.The concrete with standard maintenance to 7d and soak in sodium sulfate of 5%~15%,the compressive strength of long-term immersion increases with the concentration increasing at 30d~120d.At the wet and dry cycle,the compressive strength increased with the concentration of C35 at 30 d or 60 d,and the compressive strength with the increase of concentration increased first and then decreased at 90 d or 120 d,but the compressive strength of C45 concrete increases first and then decreases with the increase of loading ratio.The microscopic test show that the products are ettringite and gypsum.Discontinuous and continuous load on the concrete of maintenance to 7d and immersed in 15% sodium sulfate,the compressive strength increases first and then decreases with the increase of loading level,and the sulfate ion decreases and then increases with the increase of loading level at 30d~120d.