Brazil’s Sweet Asphalt: How Sugarcane Bagasse Ash Is Making BR-158 Stronger, Greener Roads

Article (with external links)

Brazil is turning a leftover from sugar production into a high-performance building material — and the results could reshape how roads are built. Researchers from Brazil demonstrated that replacing about 5% of conventional asphalt filler with sugarcane bagasse ash (SCBA) produces mixes that are stronger, more flexible and more resistant to permanent deformation; the work includes both laboratory testing and a pilot paving on a section of BR-158. Nature+1

From waste to engineering asset

Sugarcane bagasse — the fibrous residue left after juice extraction and often burned for cogeneration — produces an ash that historically posed disposal challenges. Researchers found that SCBA’s particle texture and chemistry make it a promising filler or pozzolanic supplement for bituminous mixtures, enabling reuse of an abundant local byproduct while reducing demand for quarried mineral filler. ResearchGate+1

Lab results: big gains from a small substitution

Controlled experiments substituting roughly 5% of the mineral filler with SCBA produced notable improvements in standard asphalt performance tests: increased Marshall Stability (large percentage gains reported), higher tensile strength and better rutting resistance versus the reference mix. These lab results indicated the modified mixes could deliver both greater durability and longer in-service life. Nature+1

Real road, real traffic: BR-158 pilot

Beyond the lab, a pilot section of the BR-158 highway in Paraná was paved with the SCBA-modified mix; field sampling and performance monitoring of the experimental section confirmed the laboratory trends — higher resilient modulus and improved resistance to permanent deformation under repeated loading. The pilot proves the concept at a real scale and offers a roadmap for further trials and adoption. Ecoroads+1

Why this matters — performance, cost and climate

Benefits are threefold: mechanically, SCBA-modified mixes can reduce rutting and extend pavement life; economically, they offer a local low-cost filler that shortens supply chains; environmentally, they divert ash from disposal and reduce the embodied impacts of mined fillers — supporting circular-economy goals in large sugarcane regions. Nature+1

Practical considerations and next steps

Key barriers to scale include ensuring consistent SCBA quality (ash properties vary with combustion), updating mix-design guidance to accommodate SCBA’s physical properties, setting paving best practices, and longer-term monitoring across climates and traffic classes. Regulatory acceptance and standardized testing protocols will be critical for broader adoption — steps the BR-158 pilot helps to inform. ResearchGate+1

Conclusion

The Brazilian research on sugarcane bagasse ash shows a credible path from agricultural waste to better roads. With modest substitution rates (≈5%) researchers recorded substantial durability gains in the lab and encouraging field performance on BR-158. With proper quality control, standards and scale-up trials, SCBA-modified asphalt could become a greener, more resilient option for sugarcane regions worldwide. Nature+1

External links (copyable URLs)

• Hipólito V.M., Ildefonso J.S. (2024) — Functional and structural assessment of an experimental section gap-graded modified with sugarcane bagasse ash. Scientific Reports (Nature) — article page / DOI: https://www.nature.com/articles/s41598-024-67900-2. Nature
• PubMed entry for the Scientific Reports article (includes DOI and citation metadata): https://pubmed.ncbi.nlm.nih.gov/39117764/.