Abstract: In view of the environmental problem of ammonium sulfate residue caused by rare earth mining in thesouthern part of Jiangxi, we tested the mechanical properties of corroded concrete and analyzed the regularity of strength deterioration of corroded concrete through tests of corrosion (by ammonium sulfate solution) on concretes mixed with fly ash, slag, and both fly ash and slag, respectively. Furthermore, we employed the theory of gray correlation to analyze the correlation between strength and mineral admixtures of concrete. Results show that the concrete mixed with fly ash and slag replacing cement in equal amount could significantly increase the resistance of concrete to ammonium sulfate corrosion; the strength of concrete with high content of mineral admixtures grows slowly, but the resistance to ammonium sulfate corrosion is better; mineral admixtures have good effect in delaying the decline of compressive strength of corroded concrete, but shows worse effect for flexural strength. The results of grey analysis reveal that concretes C1 (10% dosage of fly ash), C4 (40% dosage of slag), and C5 (50% dosage of slag) have the best performances in resisting ammonium sulfate corrosion.

Key words: concrete, ammonium sulfate, fly ash, slag, double mixing, correlation