Synthesis of construction materials from low-quality sand: Impact of reaction time and ethanol recycling

The rapid growth in the construction sector has resulted in depletion of raw materials for construction, while abundant low-quality sand remains underutilized. Previous studies synthesized hardened materials from low-quality sand using solvothermal processes, but reducing the reaction time, previously 24 h, is crucial for practicality. In this study, the effects of varying reaction times on hardening mechanisms were explored using several characterization techniques. The results indicate that the optimal reaction time, 6 h, significantly enhances compressive strength, exceeding 35 MPa, primarily due to the formation of microcline, potassium hydrogen silicate, and tetraethoxysilane. Additionally, the waste solution (ethanol) was recycled, achieving a high recycling rate that substantially reduced carbon emissions. This study demonstrates that a durable, sustainable construction material can be produced from low-quality sand with reduced reaction time, offering a partial substitute for concrete and an eco-friendly solution to raw material scarcity.