# Development of Sustainable Construction Materials from Inert Waste Mixtures Using the Mechanosynthesis Process

## TL;DR

This study explores using mechanosynthesis to turn construction waste into strong, eco-friendly building materials.

## Contribution

The novel contribution is the development of two new sustainable material formulations from inert waste using mechanosynthesis.

## Key findings

- Cement pastes with milled waste materials showed significantly higher compressive strength than unmilled ones.
- F1 formulations outperformed reference CEM II and CEM III pastes in compressive strength.
- Mechanosynthesis effectively transforms waste into sustainable construction materials with reduced CO2 emissions.

## Abstract

This research investigates the potential of mechanosynthesis to transform inert waste mixtures into sustainable construction materials. Three waste streams were employed: recycled glass, recycled concrete, and excavated soils. Two alternative material formulations, F1 (50% recycled concrete, 30% recycled glass, 20% excavated soil) and F2 (60% excavated soil, 20% recycled concrete, 20% recycled glass), were developed. Cement pastes were produced by partially substituting cement (CEM I) with 50% of either F1 or F2. Characterization techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (ATR-FTIR), and mechanical testing, were performed. Cement pastes incorporating milled waste materials exhibited significantly enhanced compressive strength compared to their unmilled counterparts. At 28 curing days, compressive strengths reached 44, 47, 45, and 49.7 MPa, and at 90 curing days, they increased to 47.5, 50, 55, and 61 MPa for milling conditions of 200 rpm for 5 min, 200 rpm for 15 min, 400 rpm for 5 min, and 400 rpm for 15 min, respectively. In addition, F1 formulations showed higher compressive strengths than the reference CEM II and CEM III pastes. These results highlight the efficacy of mechanosynthesis in valorizing construction waste, mitigating CO2 emissions, and creating environmentally friendly construction materials.