Structural Equation Modeling PLS-SEM to investigate waste generation in roadway construction projects in Libya

The construction industry has grown rapidly worldwide in the past decade, resulting in a significant increase in construction waste. In Libya, the construction sector has been a significant contributor to environmental degradation. To control this impact, there is an urgent need to understand how this waste is generated and how to manage it. This study aims to develop a PLS-SEM model to investigate the factors influencing construction waste generation in roadway projects. A comprehensive literature review identified 26 factors contributing to waste generation, which were then grouped into six categories: Work execution, Materials management, Design and planning, Manpower, Site management, and External factors. Additionally, the review identified 13 effects of construction waste generation, categorized under three sustainability aspects: Environmental, Economic, and Social effects. To gather data on these factors and effects, a questionnaire survey was conducted among professionals (including civil engineers, quantity surveyors, designers, and site engineers) from contractor and consultant firms involved in Libyan roadway projects, specifically those with expertise in roadway construction in the north and central regions of Libya. Respondents were asked to rank the causes and effects of construction waste generation. To determine the significance of various factor groups contributing to waste generation in road construction projects and to evaluate their sustainability-related impacts, a hierarchical model was developed and analysed using the PLS-SEM method (Smart PLS software 4.0). The model's results indicate that manpower-related factors have the most substantial influence on construction waste generation. Materials management factors were the second most significant contributors to waste in roadway construction projects. Furthermore, the study found that construction waste generation significantly impacts both economic and environmental aspects. This model could assist construction stakeholders in preventing construction waste and mitigating its adverse effects on sustainable performance.