Experimental investigations on the mechanical behavior of iron tailings powder with compound admixture of cement and nano-clay

In order to examine the mechanical performance of iron tailings powder (ITP) with compound admixture of cement and nano-clay, the mixture ratio of different cement and nano-clay is designed to prepare two kinds of ITP-based materials. The first kind ITP-based material is ITP mixed with 5%, 10%, 20% and 30% cement, and the second kind ITP-based material is the first kind materials mixed with 10% cement and 5% or 10% nano-clay. The unconfined compression strength (UCS) test, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) of two kind materials are measured with 7 days and 28 days curing periods, respectively. Results of the UCS test showed that cement and nano-clay are all beneficial for enhancing the UCS of iron tailings powder. When 5-10% nano-clay is substituted for 10% cement, the enhancement in the unconfined compression strength of cement iron tailings powder is nearly similar. Micro-test results showed that the increase in strength could be due to the involvement of cement in the hydration. The main function of nano-clay is to make the microstructure more compact owing to its small particle size. (C) 2020 Elsevier Ltd. All rights reserved.