Low-carbon multiobjective optimization for repetitive projects based on crew-based scheduling strategy

Repetitive projects represent a significant proportion of the construction industry. Effectively reducing carbon emissions from such projects plays an important role in mitigating climate change. This study employs the Line-of-Balance (LOB) method as a scheduling tool to explore the trade-offs among carbon emissions, duration, and costs in repetitive projects. Initially, this study addresses the limitations of traditional LOB scheduling strategies and proposes a new scheduling strategy from the perspective of crews. Moreover, the "controlled acceleration"routine is extended within the LOB framework. Subsequently, this study elucidates a calculation method for total carbon emissions during the construction phase of repetitive projects and establishes a trade-off model among carbon emissions, duration, and costs based on the proposed strategy. The NSGA-II algorithm was then devised to solve the Pareto set. Finally, the effectiveness of the proposed strategy was validated through a highway project. The research findings demonstrate that adopting the Crew-based Scheduling Strategy significantly reduces project carbon emissions and costs while shortening the duration when compared with traditional strategies. Furthermore, the controlled acceleration routine enhances resource utilization and achieves superior project performance. This study provides robust support for advancing the construction industry toward low-carbon and sustainable development.