Evaluation of Sewage Sludge Ash in Asphalt Concrete Using Disk-Shaped Compact Tension Testing

A study was conducted evaluating the effects of sewage sludge ash (SSA) in hot mix asphalt (HMA) as mineral filler and/or as a fine aggregate substitute. For the purposes of this study, 0% and 2% SSA by weight of aggregates were used in HMA samples. Disk-shaped compact tension testing (DCT) was utilized to determine the fracture energy of the HMA samples. Through the DCT test method, it was found that the fracture energy for samples containing 0% and 2% SSA by weight of aggregates were 3.41 J/m2 and 3.15 J/m2 respectively. From this testing it was concluded that the HMA with 2% SSA shows similar performance as that of 0% SSA. Since the performance of the HMA does not drop with addition of 2% SSA, future studies could be conducted analyzing the effects of higher percentages of SSA, which could significantly reduce the amount of raw materials required in construction.