Multi‐Objective Optimization on Durability and Fatigue Properties of Unsaturated Polyester Resin Modified Composite for Bridge Deck Pavement Based on Multi‐Scale Analysis

ABSTRACT To fabricate unsaturated polyester modified composite (UPMC) with excellent durability and fatigue properties for bridge paving layer, the multi‐objective optimization of mix proportion was implemented from multi‐scale detection. In this study, waterborne unsaturated polyester resin (WUP) was pre‐processed via phase inversion emulsification; the variation law on cracking resistance and chloride permeability was studied through combination of experimental analysis and level assessment; the attenuation law and mechanism of sulfate corrosion resistance were probed by analyzing the micro‐pore morphology and phases composition; the damnification and enhancement mechanism of fatigue properties were investigated utilizing fatigue‐life analysis and nano‐indentation characterization, herein fatigue‐life prediction as a function of stress levels and failure probability was completed based on multi‐parameter Weibull distribution. The proportional optimization design was conducted by utilizing hybrid multi‐index ellipsoidal gray‐target decision (HMEGD) model. The results demonstrated that WUP incorporation exerted a remarkable inhibiting effect on cracking behavior of UPMC at ultra‐early and curing period, manifesting as a reduction of crack area and quantity and a delay in crack initiation time; concurrently, chloride ion permeation and sulfate corrosion resistance could be enhanced by 8.92%–26.17% and 9.71%–23.28% due to the replenishment of interior micropore, the abatement of pore interconnectivity; the fatigue‐life at the stress‐level of 0.65–0.90 was prolonged by 18.23%–65.08% owing to the densification of internal micro‐defects and interface transition zone (ITZ). The established fatigue‐life equation at varying failure probabilities had a certain reliability for investigation of fatigue property. Based on the coordinative optimization of HMEGD model, the proportion of 3%–6% WUP was recommended for UPMC.