Research into the Shrinkage Characteristics of Cement-Stabilized Macadam Improved by Pyrolysis Residue of Oil Sludge

Pyrolysis residue of oil sludge (PROS) is a solid waste generated during the oil recovery process, which contains active ingredients to improve the mechanical properties of cement-stabilized macadam (CSM). However, the effect of PROS on the shrinkage properties of CSM needs to be further investigated. Analytical techniques such as X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), heat of hydration: Proton Nuclear Magnetic Resonance: ¹H NMR is a nuclear magnetic resonance technique used to detect the behavior of hydrogen nuclei (protons) within molecules, dry shrinkage, and temperature shrinkage were used to investigate the hydration characteristics of sludge-cement-stabilized macadam (SCSM) with different PROS dosages. The main objective was to establish the correlation between the water loss rate, shrinkage strain, shrinkage coefficient, and PROS substitution level of SCSM. The results indicated that the cumulative water loss of SCSM increased as the proportion of cement replaced by PROS increased. The internal curing effect caused by the porous structure and oil content of PROS could effectively mitigate the shrinkage and deformation of SCSM during curing. The dry shrinkage coefficients of SCSM with replacement rates of 10%, 20%, and 30% were 10%, 15%, and 22% lower, respectively, and the temperature shrinkage coefficients were 8%, 17%, and 24% lower, respectively, compared with those of CSM. The optimum percentage of cement replacement by PROS is 20%.