Effect of recycled sugarcane bagasse as an internal curing additive on mechanical strength, abrasion resistance, and drying shrinkage of paving concrete

Abstract

The utilization of agricultural by-products in paving concrete (PC) has been increasingly explored as a strategy to reduce material-related environmental impacts in pavement construction. This study investigates the influence of recycled sugarcane bagasse (RSB), incorporated into PC at volume fractions ranging from 0 to 2.5 vol.%, on mechanical strength, abrasion resistance, and drying shrinkage behavior. Compressive, flexural, and splitting tensile strengths, surface abrasion loss, and drying shrinkage were evaluated up to 56 days in accordance with relevant Vietnamese standards. Test results indicate that increasing RSB content significantly affects concrete’s properties. At 56 days, the compressive strength of the control mixture reached 48.2 MPa, whereas the mixture containing 2.5 vol.% RSB exhibited a substantially reduced strength of 8.9 MPa. Surface abrasion loss increased progressively with RSB addition, rising from 0.42 g/cm² for the control mixture to 0.98 g/cm² at 2.5 vol.% RSB. A strong inverse linear relationship was observed between compressive strength and surface abrasion loss across all mixtures and curing ages (R² = 0.88), highlighting the dominant role of matrix compactness in controlling abrasion resistance. Drying shrinkage exhibited a non-monotonic response to RSB incorporation. Mixtures containing 0.5–1.0 vol.% RSB showed shrinkage comparable to or lower than that of the control mixture, whereas higher RSB contents resulted in increased shrinkage at later ages. Although higher RSB dosages caused a noticeable reduction in flexural performance, the mixture containing approximately 0.5 vol.% RSB satisfied the 28-day flexural strength, compressive strength, and surface abrasion requirements specified for level-IV road, while providing measurable shrinkage mitigation. Further mixture optimization is required to enable the use of higher RSB contents while maintaining adequate mechanical performance for pavement applications.