Effect of Iron Tailings Powder on the Mechanical Properties and Calcium Hydroxide Content in Limestone Powder Concrete

This is an article in the field of ceramics and composites. Influence of the mixed mineral powder content and proportion on the performance of concrete were studied. The results show that with the continuous increase of the proportion of mixed slag powder, the strength of the mixed slag powder concrete shows a change rule that first increases and then decreases. And the maximum value is achieved when the ratio of compound ore powder is 1∶2. Under the effect of the same number of freeze-thaw cycles, the mass loss rate of concrete shows a trend of first decreasing and then increasing with the increase of the proportion of mixed mineral powder. However the relative dynamic elastic modulus of concrete shows a trend of first increasing and then decreasing. At the same measuring position, as the proportion of compound slag powder increases, the chloride ion content in the compound slag powder concrete shows a continuous decrease. And when the ratio is 1∶2, the chloride ion content of the mixed slag powder concrete decreases faster. The comprehensive test results show that the strength characteristics of limestone tailings concrete are the best when the content of limestone tailings is 20%. The strength and durability of concrete reach the best when the ratio of mixed mineral powder is 1∶2.