Sustainable Marshall Mixes: LDPE‑Modified Asphalt mix from Waste Polythene and Milk Pouches

This Study focuses on using low-density polyethylene (LDPE) waste from polythene bags and plastic milk pouches in asphalt mix design as a sustainable modifier. The main problem with plastic waste is that it is non-biodegradable and has a considerable life span, which has caused serious problems in today's life, ranging from soil contamination to blocked drains and urban flash floods. The objective of this study is to use LDPE at varying percentages of 4.5%, 5.5%, 6.5%, and 7.5% by weight of bitumen in a marshal mix design and evaluate physical properties and Marshall mixes volumetrics. The LDPE was incorporated into the mix using the dry mix process. Waste Polythene bags and plastic milk pouches were collected and cleaned; after cleaning LDPE, they were shredded using mechanical shredding. Sieving was done, and sample sizes passed from the 2.36mm sieve were selected. These shredded LDPE particles were mixed at varying percentages of 4.5%, 5.5%, 6.5%, and 7.5% by weight of bitumen, and physical properties and Marshall mix volumetrics were determined. Binder test results show that penetration and ductility of modified bitumen decreased when the LDPE content increased, whereas the softening point increased. Marshall stability increased from 12.6 KN to 15.5 KN; flow value ranged from 2.45 mm to 1.95 mm; Voids filled with bitumen (VFB) varied from 75.02 % to 76 %, and Voids filled with aggregate (VMA) ranged from 16.36 % to 16.65 %.