Circularity-oriented optimization of plastic-modified concrete: a hybrid ai framework linking morphology, interface chemistry and durability evolution

This study presents an original computational–experimental framework for the circularity-oriented optimization of plastic-modified concrete by integrating morphology-aware mix design, chemically informed interfacial engineering, thermo-mechanical durability forecasting, lifecycle circularity assessment, and implementation feasibility analysis. Conventional plastic-modified concrete design is limited by weak polymer–cement interfacial bonding, particle morphology variability, and the absence of integrated lifecycle-aware optimization. To address these limitations, the proposed framework combines three-dimensional particle morphology characterization, spectroscopic and nano-mechanical interfacial evaluation, convolutional neural network (CNN)-based morphology classification, multi-objective mix optimization, durability prediction, and circularity assessment within a unified computational architecture. Experimental validation showed that concrete containing alkaline-treated polyethylene terephthalate (PET) at moderate replacement levels achieved compressive strengths above 35 MPa, Bonding Integrity Index values greater than 0.75, and a 1.7–1.9-fold increase in thermal-cyclic fatigue life. Life cycle assessment estimated a Circular Utilization Factor of 0.67 and a reduction of 25–30 kg CO₂/m³, primarily due to localized material sourcing, lower clinker consumption, and improved end-of-life recovery. In addition, the feasibility analysis confirmed strong potential for practical implementation, with feasibility scores exceeding 0.80 and cost–benefit ratios greater than 1.0. Under the investigated PET, HDPE, and PP systems and the specified laboratory and regional assessment conditions, the proposed framework provides a promising integrated design strategy linking particle morphology, interfacial chemistry, durability, circularity, and implementation feasibility for plastic-modified concrete.