Physical and mechanical characterization of solid waste collected from rural areas of China: Experimental study

To support the landfill design and waste management in rural areas of China, solid waste covering eight provisional regions was collected and tested in the laboratory to characterize its physical properties (composition, moisture content, specific gravity, dry unit weight) and mechanical properties (compressibility and shear strength). The results show that, compared with solid wastes from urban areas (MSW), solid waste from rural areas (RSW) comprised a much lower content of soil-like, gravel, and inert waste and a significantly higher content of combustible waste, thereby yielding a much lower specific gravity and dry unit weight. Similar to MSW, the compression index of RSW correlated well with its physical properties. However, its strength properties displayed divergence. Notably, the friction angle φ' of RSW remained relatively consistent, ranging from 28.4° to 30.9°. This narrow range is attributed to RSW's higher combustible-to-inert (CI) ratio compared to MSW. The cohesion intercept c' of RSW ranged from 13.5 to 24.9 kPa, showing a positive correlation with the fiber content without considering contribution from paper waste. This finding combined with data from the literature further revealed that the trend of increasing cohesion intercept with increasing fiber content became weakened over time. Relationships between φ' and c' versus C/I for RSW observed in this study will serve as an extension to the existing finding reported for MSW in the literature, i.e., for predominately combustible waste with C/I exceeding 10, constant values of strength parameters (i.e., moderate values φ' = 30°, c' = 20 kPa) are recommended. The results of this study are useful for the capacity design and slope stability analysis of landfills as well as waste recycle and reuse, ensuring a sustainable development of environment in China.