Método integrado de análise econômica e ambiental do ciclo de vida de pavimentos aeroportuários brasileiros para apoio à tomada de decisão em manutenção e reabilitação

Abstract

The growing demand for safety and operational efficiency in airports reinforces the need for more sustainable and economically efficient solutions for airport pavement management. In this context, Life-Cycle Cost Analysis (LCCA) emerges as a tool to support rational decision-making over time, allowing the evaluation of costs associated with different maintenance and rehabilitation (M&R) strategies. However, many LCCA studies focus primarily on functional parameters, such as the Pavement Condition Index (PCI), without incorporating indicators related to skid resistance, which are essential for the safety of landing and takeoff operations. In addition, LCCA does not incorporate the environmental impacts associated with M&R interventions. Given this context, this study aimed to develop an integrated economic and environmental analysis method for the design period of Brazilian airport pavements, combining Life-Cycle Cost Analysis (LCCA) and Life-Cycle Assessment (LCA), while considering functional, structural, and skid resistance parameters. Data from a Brazilian runway, provided by the National Civil Aviation Agency, covering the period from 2014 to 2023, were used, including PCI, friction coefficient, macrotexture, and the Cumulative Damage Factor (CDF), obtained using the FAARFIELD 2.1.1 software. Prediction models were developed in Python, using Gated Recurrent Unit (GRU) recurrent neural networks for the friction coefficient and macrotexture, and a deterioration rate model for PCI. The combination of performance predictions with the structural analysis performed in FAARFIELD 2.1.1 allowed the identification of M&R needs and the simulation of different intervention scenarios for time horizons of 20, 30, and 40 years through decision trees. The proposed method integrated both financial and environmental costs. The environmental impacts were estimated through an LCA conducted in the SimaPro Demo software, using the ReCiPe Midpoint (H) method, considering a functional unit of 1 m2 of runway, followed by the monetization of CO2 equivalent emissions. Additionally, a sensitivity analysis was carried out considering different discount rates. The friction coefficient and macrotexture models presented satisfactory performance, although the accuracy of the macrotexture model decreased for higher values. Preventive maintenance proved to be the most advantageous alternative in short-term horizons, reducing the Net Present Value (NPV) of M&R costs and postponing high-cost corrective interventions. However, in longer horizons, environmental impacts increased due to the recurrence of delayed corrective interventions, making the NPV of environmental costs more sensitive to the accumulation of emissions over time. Nevertheless, the NPV of total costs remained lower in the scenario prioritizing preventive maintenance, demonstrating its economic robustness. The sensitivity analysis of the discount rate showed that, over a 20-year horizon, the total NPV presented low variation, while over 30 years the difference between discount rates was moderate. Over a 40- year horizon, delayed costs—particularly environmental costs—made the total NPV more sensitive to variations in the discount rate. Overall, the proposed method demonstrates strong potential to support decision-making in defining M&R strategies. By integrating functional performance, skid resistance, structural behavior, and environmental impacts, this research contributes to more efficient and sustainable airport pavement management practices, aligned with the increasing demands for operational safety and economic rationality in Brazilian airports.