Mechanical characterization of Rice Husk Ash incorporated bituminous concrete

Effective utilization of Rice Husk Ash (RHA) effectively reduces waste, creates value-added products, and enhances environmental sustainability in rice-producing countries. The current investigation explores the potential of using RHA in pavement construction which can result not only in effective disposal of RHA but also in enhanced structural strength. The present study aims to identify an optimum dosage of RHA in bituminous mixes based on the performance characteristics of these mixes incorporating various percentages of rice husk ash as a replacement for the aggregate fillers. The dosages of RHA used in the study were 0, 5, 10, 12, and 15% of filler proportion. The surface morphology analysis of RHA was carried out using Scanning Electron Microscopy (SEM). The volumetric and mechanical properties of bituminous mixtures containing various percentages of RHA were assessed using Marshall stability, indirect tensile strength, and resilient modulus tests. The rutting and cracking performance was evaluated using dynamic creep and indirect tensile asphalt cracking tests (IDEAL CT), respectively. It was observed that an increase in the RHA content from 0 to 10% resulted in an increase in the Marshall stability, indirect tensile strength, and resilient modulus of the mixes. However, an increase in RHA content above the optimum value resulted in a reduction in the mechanical properties. The rut resistance was highest for the RHA mixes with 12% RHA both at 45^oC and 55^oC. However, the cracking tolerance of the RHA mixes was lower compared to the conventional mixes, which needs to be improved through balanced mix design approaches.