What influences the on-site recycling behaviour of C&D plastic waste in Australia? An action determination model approach

While the recycling of construction waste has received widespread attention, plastic waste generated at construction sites has been overlooked. At the same time, existing studies on pro-environmental behaviour have only considered practical knowledge of implementing recycling, while ignoring the possible impact of circular economy knowledge on recycling behaviour. This study investigates on-site personnel's behaviour regarding C&D plastic waste recycling through the lens of the comprehensive action determination model (CADM), which uniquely incorporates behaviour as a key variable and extends with moderating effect of knowledge of the circular economy. Utilizing Partial Least Squares Structural Equation Modelling (PLS-SEM), results indicate that perceived behavioural control is the most substantial factor influencing recycling behaviour of plastic waste on construction sites rather than intention. This is in stark contrast to existing pro-environmental behaviours research and reflects the importance of providing resources and encouragement to increase personnel's confidence in performing recycling behaviours on site, contributing more to actual behaviours than intention. Key areas for improvement were identified, including management encouragement, resource allocation (site area, timeline, budget), and recycling training. Contrary to expectations, awareness of the circular economy did not statistically significantly moderate the predictors of recycling behaviour and intentions, perhaps because participants had limited knowledge of plastic consumption and recycling rates in the construction industry. As construction personnel become more familiar with the circular economy, future research should re-evaluate these moderating effects and consider conducting categorical moderation analyses with larger sample sizes, incorporating variables such as work experience, project type, and project phase.