A study on mechanical properties and permeability of steam-cured mortar with iron-copper tailings

With the development of construction industrialization, the use of steam curing to produce precast concrete is widely used. In order to recycle long-term stacked tailings waste, iron-copper tailings (ICT) waste is comprehensively utilized in steam-cured mortar (SCM). The effect of ICT substitution level on the mechanics and durability of steam-cured mortars is investigated in this study. The research results show that the use of appropriate ICT instead of river sand in the production of mortar is beneficial to the enhancement of the mechanics and durability of the mortar. When the replacement level of ICT is 10%, the 1-d and 28-d compressive strength of SCM are increased by 1.09% and 7.27% respectively compared with plain mortar. SCM mixed with 10-20% ICT has lower permeability compared to plain samples, and further increasing the substitution level of ICT is not benefit the development of mortar durability. Since ICT has better conductivity compared to river sand, it makes the resistivity of SCM decrease with the increase of ICT content. Microstructural studies show that the addition of a small amount of ICT reduces the porosity of SCM and refines its pore structure. Meanwhile, the ICT and cement matrix exhibits a more dense ITZ than the river sand and cement matrix. Recycling of ICT also shows better economic and environmental benefits in SCM. This study provides a theoretical basis for recycling composite tailings waste in prefabricated components.

Automated summary

With the development of construction industrialization, the use of steam curing to produce precast concrete is widely used. In this study, the comprehensive utilization of iron-copper tailings (ICT) waste in steam-cured mortar (SCM) is investigated. The results show that the addition of appropriate ICT improves the mechanics and durability of SCM. Furthermore, the recycling of ICT in SCM demonstrates better economic and environmental benefits.