An in situ method for translation of acid sludge to modified asphalt paving materials

The acid sludge, which was obtained from the recovery of used oil, was disposed through an in situ mixing with styrene–butadiene–styrene (SBS) modifier during its neutralization reaction to afford an usable road paving material. Different contents of SBS (1.0%, 2.0%, 4.0%, and 6.0% by weight of asphalt) were blended, respectively, with an contrast industrial 70/100 paving grade asphalt and the neutralizing sludge binder. Unmodified (0% SBS), modified sludge asphalt (SBA), and industrial binders (IB) were subjected to the tests of physicochemical, tensile, toughness, and storage-stability. The analyses of test results show that the tensile and toughness properties of SBS modified sludge asphalt are much improved, and its storage-stability is better than conventional SBS modified industrial binders. The results revealed that SBA is a stable binder for containing calcium sulphate interacted with SBS, and it can be confidently used as paving materials, hence a promising disposal method for acid sludge of used oil.

Figure optionsDownload as PowerPoint slideHighlight
► Acid sludge was translated into paving materials.
► Styrene–butadiene–styrene was added during neutralization.
► The in situ method is promising in the disposal of acid sludge.