Effect of siderurgical aggregates on concrete exposed to saline environments

Abstract

Using recovered waste to obtain high-performance structural concrete is possible and justified by the saving in natural resources and the avoidance of deposit in landfills. The technical justification for these new and ecological concretes must be based on proving their mechanical performance and durability. The former has been widely studied, while the latter has been very vaguely studied, with controversies being found in this regard. This research aims to shed light on the ability of concrete with siderurgical aggregates to resist processes that lead to early deterioration or alteration of its microstructure. To this end, concrete with siderurgical aggregates and limestone reference concrete were subjected to traditional durability tests, as well as novel tests consisting of exposure to saline environments. The results obtained show that the concretes with siderurgical aggregates exhibit a similar behavior in terms of gas and water permeability, accelerated carbonation and resistance to freeze-thaw cycles (except for total replacements) to the limestone reference concrete. Exposure to a salt spray chamber and to seawater show the same effect in terms of chloride profiles, while the steel reinforcements embedded in the concrete did not suffer corrosion for any of the exposure times. These results open the door to using these concretes in maritime work, both onshore and offshore.