Effect of Mixed Iron Tailings and Fly Ash Content on the Performance and Microstructure of Concrete

This is an article in the field of ceramics and composites. The changes of resistivity, compressive strength and chloride ion migration coefficient of concrete under different dosages are used to evaluate the durability of concrete. The impermeability, mechanical properties, and chloride ion corrosion resistance of concrete under the action of different iron tailings content and different fly ash content are studied. The effect of adding different proportions of iron tailings and fly ash on the performance of concrete is analyzed.The results show that the compressive strength of concrete reaches the maximum when the content of iron tailings and fly ash is 30%. However, the larger the proportion of fly ash and the smaller the proportion of iron tailings, the worse the compressive strength, impermeability and resistance to chloride ion corrosion of concrete. Therefore, in the actual preparation of concrete, a mixing ratio of a large amount of iron tailing sand and a small amount of fly ash should be used. With the increase in the content of iron tailings and fly ash, the hydration heat release rate and total heat release of iron tailings also show a decreasing trend under the same hydration time. This shows that the addition of iron tailings and fly ash greatly reduces the hydration heat release rate and total heat release of concrete. With the increase in the amount of iron tailings and fly ash, the pore size value corresponding to the peak point of the concrete pore size distribution curve is also increasing, but the increasing amplitude is getting smaller and smaller.