Lignosulphonate as a Sustainable Asphalt Modifier: A Review

The increasing demand for sustainable pavement materials has intensified interest in bio‑based additives for bitumen modification. Among these, lignosulphonate (LS), a byproduct of the pulp and paper industry, has emerged as a promising, cost-effective, and environmentally friendly modifier for asphalt binders. This review synthesizes current research on the effects of incorporating three dosage levels of LS (low, medium, and high) on the physicochemical, rheological, and mechanical properties of bitumen and asphalt mixtures. Studies consistently report that low to medium LS contents improve binder viscosity, reduce temperature susceptibility, and enhance workability during mixing and compaction. Medium dosages often demonstrate optimal performance, contributing to increased softening point, improved rutting resistance, and better moisture sensitivity resistance in asphalt mixtures. Conversely, excessive LS addition may lead to reduced stiffness and increased moisture susceptibility due to its hydrophilic nature. The review highlights key mechanisms governing LS bitumen interaction, including hydrogen bonding, dispersion effects, and biopolymer reinforcement. Overall, the literature confirms that lignosulphonate is a viable green additive for improving asphalt performance when used within an optimal dosage range, supporting its broader adoption in sustainable pavement engineering.

کلیدواژه ها:

Lignosulphonate ، Bitumen ، Asphalt ، Bio-based modifier ، Pavement performance ، Sustainable additives