Penetration inhibitor potential of ceramic waste–cement composites exposed to coastal environments

An intricate relationship exists between the durability performance of reinforced concrete and the migration of chloride ions, particularly in marine and coastal environments. The aim of this work was to study the influence of ceramic waste (CW) as cement replacement on the chloride migration of limestone aggregate concrete, based upon rapid chloride migration testing through the non-steady-state migration coefficient according to NT build 492. The chloride penetration inhibitor potential of CW in concrete was assessed through physical and chemical analyses. Mortar and concrete samples with two different water/binder ratios (0.5 and 0.7) were designed. The cement replacement ratios were 10, 15 and 20% by weight. The focus of the study was on the transport properties (particle size distribution, density, absorption, capillarity, sorptivity, chloride migration coefficient) and mechanical properties (compressive strength, strength activity index), along with chemical and environmental (cement intensity index) characterisation of CW–cement concretes. The results showed a significant improvement in the chloride penetration resistance of the CW–cement concrete, even considering the selection of limestone aggregates. The concomitant pozzolanic/filler effect of CW particles provided further densification and refinement of the microstructure, leading to enhancements in the physical and mechanical properties, and thus in the eco-efficiency of the CW-blended concrete.