Investigating the utilization of oxidized textile residue as a strengthening substance in the composition of subgrade soil for pavement construction

The textile industry, vital in the country's industrialization and playing a crucial role in the national economy, generates solid byproducts known as textile sludge. Integrating waste into stabilized soils, along with textile sludge (TS), fly ash (FA), and asphalt additives, offers scientific, economic and sustainability benefits. This study aimed to examine the subsurface solidification technique employing sludge and two supplement additives (asphalt and fly ash additive) implemented on pavement groundwork and supporting layers. The research involved characterization tests and physical soil stabilization with TS and stabilizers (fly ash, and asphalt) at proportions of 2.5%, 5%, 7.5%, 10%, 15%, and 20% as soil additives, which were carried out experimentally. The test results highlighted the potential application of soil-textile sludge mixtures in pavement strata (support and subgrade). The inclusion of fly ash has been proven to be the most effective method for chemically stabilizing the sludge. The maximum dry density was achieved with soil containing 10% textile sludge, supplemented with 15% fly ash. This resulted in a notable increase in UCS value from 235 kN/m2 to 242 kN/m2 and an improvement in CBR value from 4.1% to 9.12%. Furthermore, the addition of 5% bitumen further enhanced the UCS value, reaching 451 kN/m2 and significantly increased the CBR value to 21.6%. Stabilizing textile sludge offers significant environmental benefits by mitigating issues associated with improper waste disposal.