Characterization of the mechanical properties of eco-friendly concrete made with untreated sea sand and seawater based on statistical analysis

Natural sea sand and seawater, as alternative sustainable materials for mitigating environmental pollution and resource shortage of traditional concrete production using river sand and freshwater, are gaining increasing attention from researchers worldwide. In this paper, an innovative and sustainable eco-friendly concrete using different kinds of sea sand and seawater has been investigated. The influence of incorporated ions by sea sand and/or seawater on the mechanical properties of concrete has been explored. Due to the accelerated effect of additional ions on cement hydration process at early age, the volume of intrusion capillary pores, which are responsible for the macroscopic strength of concrete, is found to be relatively higher within seawater sea-sand concrete (SWSSC). The statistical analysis of compressive strength shows that the three kinds of studied SWSSC exhibit no intrinsic difference compared to normal concrete. Although the incorporation of sea sand and especially seawater impedes somewhat the concrete strength enhancement with aging, the global mechanical behavior of SWSSC is still comparable to that of ordinary concrete. With proper selection and preliminary test, the incorporation of sea sand and/or seawater in plain concrete as well as in concrete with corrosion-free reinforcement is promising for the environmentally friendly production of concrete. (C) 2019 Elsevier Ltd. All rights reserved.