Experimental investigation on the performance of concrete incorporating fine dune sand and ground granulated blast-furnace slag

Utilization of high-volume fine dune sand (FS) as fine aggregate in the production of concrete products that incorporate industrial by-products such as ground granulated blast-furnace slag (GGBFS) is an issue that has received much attention from research scholars worldwide. This issue is particularly meaningful for countries such as Vietnam where fine aggregates (i.e., natural river sand [RS]) are scarce and sufficient quantities of local FS and industrial by-products are readily attained. This study was designed to evaluate the mechanical properties, drying shrinkage, and durability performance of concrete specimens, prepared with a water-to-binder ratio of 0.40, using, using 50% and 100% FS in combination with 35% GGBFS as RS and cement replacement, respectively. The experimental results demonstrated that replacing RS with FS negatively affects concrete performance and that replacing cement with GGBFS enhances concrete performance. The concrete specimen prepared with 50% FS and 35% GGBFS exhibited the best performance of all of the specimens, including the reference specimen, in terms of mechanical properties, drying shrinkage, and durability. Although replacing RS with FS only was found to reduce the workability, mechanical strength, and ultrasonic pulse velocity and to increase the drying shrinkage, porosity, water absorption, and chloride permeability of the concrete specimens, the specimens with 50% and 100% FS combined with 35% GGBFS exhibited significantly improved performance and exceeded the minimum standards required for use in most commercial construction activities. Furthermore, the results of the environmental assessment proved the value of combining FS and GGBFS into a green concrete solution that reduces both CO2 emissions and energy consumption to promote sustainable development. Finally, the findings of this study validate the applicability of FS and GGBFS as alternatives to conventionally mined materials in the production of environmentally friendly concrete.