Optimization of structural solutions for paving and artificial structures based on a multi-criteria analysis of the cost of the life cycle, durability, maintainability and carbon footprint

Abstract

The article is devoted to the optimization of structural solutions for pavement and civil engineering structures based on a multi-criteria analysis of life-cycle cost, durability, maintainability, and carbon footprint under the conditions of the industry’s transition to life-cycle contracts and climate constraints. The aim of the study is to develop a methodological and mathematical framework that allows for the selection of pavement and span structures not by minimal initial estimated cost, but by an integrated efficiency criterion aggregating economic, technical, and environmental indicators. The empirical basis consists of data on 1,240 road sections and 315 bridge structures in three road-climatic zones for the period 2010-2022, including data from PMS systems, laboratory material tests, cost estimates, and operational reports. The methodology is based on combining life-cycle cost analysis using the NPV scheme with a discount rate of 3-8% and carbon footprint assessment according to ISO 14040 standards «from cradle to grave», numerical modeling of structural stress-strain states using the finite element method, and multi-criteria optimization employing the analytic hierarchy process and genetic algorithms. It is shown that traditional asphalt concrete, modified, and cement concrete pavements form fundamentally different profiles of capital and operational costs, inter-repair periods, and CO2-equivalent emissions; rigid structures are characterized by a higher initial carbon footprint but a lower gradient of accumulated costs. For bridge structures, a fundamental contradiction is identified between reducing the mass of the span structure and increasing the energy intensity and carbon intensity of production when switching to high-strength steels and composites, partially offset by high recycling potential. It is established that an increase in initial investments by 15-20% when using optimized structures and modern materials can reduce the discounted life-cycle cost by 30-40% and the carbon footprint by up to 25% due to extended inter-repair intervals and reduced labor intensity of repair operations. The formation of a set of Pareto-efficient solutions and the calculation of a dimensionless integrated efficiency index demonstrate that environmental indicators, when the full life cycle is considered, do not contradict economic rationality but act as a driver for the implementation of innovative technologies. It is concluded that the integration of the developed algorithms into BIM environments, digital twins, and asset management systems is advisable to shift from static standardization to dynamic management of transport infrastructure based on risk-oriented and climate-resilient strategies.