Crack resistance of waste cooking oil modified cement stabilized macadam

Application of waste cooking oil (WCO) in transportation infrastructure has great potential to significantly improve clean production practice in industry. In view of the successful use of WCO modified asphalt mixture, this study investigates the potential of incorporating WCO into cement stabilized macadam. The study first investigated the macro and micro structural properties of the WCO modified cement stabilized macadam in the laboratory, then a test road was paved to evaluate its performance. The preliminary results indicated that both the initial compressive strength and splitting strength of the WCO modified macadam was decreased, but their strength results were close to those of the control with age. Oil type had a significant effect on the splitting strength, but only a small influence on the compressive strength. The compressive resilient modulus of the WCO modified macadams was decreased due to the increasing flexibility. The dry shrinkage test showed that WCO could effectively reduce the dry shrinkage coefficient of the cement stabilized macadam. Moreover, the fatigue cracking resistance of WCO modified macadams was better than that of the control. One possible reason for the improved cracking resistance of WCO modified macadams was that cracks were filled or separated into smaller cracks by C–S–H glue with age, as shown by scanning electron microscopy images. The field test application reveals that the WCO modified cement stabilized macadam subbase is an acceptable and economical alternative for roadway construction