Comparative fresh and hardened performances of concrete in using various artificial and natural sands

Four concrete types were experimentally investigated using different fine aggregates as follows: natural river sand (M20RS), artificial crushed sand (M20CS), artificial gravel sand (M20GS), and hybrid sand (M20HS) containing 50% river sand and 50% gravel sand by mass. First, there were little differences in both compressive strength and elastic modulus of the concretes (less than 6.4%). Second, compared to M20RS using river sand, the concretes using artificial sands positively demonstrated their higher flexural strengths (3.5-11.1%) and splitting strengths (4.4-12.8%) at 28-day age. In contrast, they negatively revealed their lower workabilities (21.4-35.7%), water permeation resistance (34.3-53.7%), and abrasion resistance (2.9-20.6%). Third, the compressive, flexural, and splitting strength of the concretes increased with time under water curing. Under sulfate attack, the compressive strengths of the concretes were observed to enhance at 56-day age but reduced at 90-day age. The reductions in compressive strengths owing to sulfate attack were 2.6-7.7% at 56-day age and 11.8-24.4% at 90-day age, in comparison to water curing. Finally, the Weibull distribution analysis was performed to explore the the effect of fine aggregate types on concrete strength sensitivity.