Open Collections

Rahman, Saadman Sakib

University of British Columbia

The textile industry accounts for the increasing volume of debris in the landfills ensued by the dynamic trend of the global fashion industry. The voluminous waste is responsible for extensive environmental degradation which has led experts to introduce sustainable ways to promote its circular economy. A potential application can be the stabilization of highway subgrades. Cement is generally used as a chemical stabilizer to improve the engineering performance of subgrades which also has a massive carbon footprint. Thus, resurfaced wood ash is used in the study as an effective alternative to cement for stabilizing weak subgrades. Moreover, fiber reinforcement using cementitious materials is a well-known topic among researchers in geotechnical engineering. Hence, this study evaluated a novel application of assorted pre-consumer apparel waste as a reinforcing element in wood ash-treated subgrade. In this study, an optimized mix design of soil-ash-textile (SAT) geo-composites was formulated by varying the fabric aspect ratio, content, and mixing technique. The design was optimized based on the compaction and unconfined compressive strength (UCS) test results. Later, the optimum combination was subjected to a splitting tensile strength (STS) and direct shear tests to determine the indirect tensile strength and shearing behavior, respectively. This study also looked closely at the microstructural behavior, elemental composition, and leachate properties of the optimized SAT geo-composite to evaluate its structural integrity and environmental impacts. The results from the UCS and STS studies showed a strength gain of 170% and 87.5%, respectively. Outcomes of the direct shear test displayed a drop in the friction angle, although there were improvements in the post-peak strength retention behavior. Microstructural exploration helped decipher the reasons behind the improvement in inter-particle bonding due to the reinforcing effect, while spectroscopies highlighted no major change in the wood ash-soil chemical reactions due to the presence of textile waste. Leachate toxicity analysis unveiled a major reduction in the concentration of the constituents due to the downcycled application in contrast to traditional disposal. The findings of the study can help provide practical guidelines on this application, negating the carbon footprint of the traditional stabilization practices, serving as a cleaner alternative to landfilling.

Text

2023-03-15

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/80699

Civil Engineering

University of British Columbia

UBCO

http://creativecommons.org/licenses/by-nc-nd/4.0/