Application of self-produced artificial sand in the production of green mortar

Abstract

Due to the large disposal of locally industrial wastes and the shortage of natural resources, turning industrial by-products into green artificial materials has been attracting many researchers in the world. Following this trend, this study evaluated the potential application of self-produced artificial sand (AS) in the production of green mortar. The AS was produced by the alkali-activated method using a mixture of 36.4% fly ash, 36.4% slag, 3.5% 10M NaOH solution, 11% Na2SiO3 solution, and 12.7% water. The mortar mixtures were designed based on the densified mixture design algorithm with the incorporation of the AS as the substitution of natural sand (NS) by 0 – 100 wt.% (interval of 20%). The engineering properties of the mortar samples in both fresh and hardened states were evaluated through the tests of workability, compressive strength (CS), water absorption (WA), and shrinkage/ expansion. The experimental results showed that the mortar sample incorporating 20% of AS to replace NS performed superior engineering properties in comparison to other samples. Further increasing the AS content generally caused a negative impact on the mortar’s performance. Increasing AS content beyond 20% systematically decreased the CS while both WA and expansion were increased noticeably. However, the properties of the green mortar produced for this study satisfied all of the requirements of the official Vietnamese standards. Thus, the research results further confirmed a great potential in producing green mortar using AS to either partially or fully replacement of NS. In addition, the use of AS greatly contributes to not only saving natural resources but also limiting the negative effects on the environment due to the exploitation and use of naturally sourced materials.