Flow modelling of construction site materials and waste logistics A case study from Cape Town, South Africa

Purpose - The purpose of this paper is to determine the nature and extent of the current practice of logistics in the construction industry and to investigate the utility of reverse logistics in a construction context. Design/methodology/approach - A pilot study was utilised to devise a method for the identification and measurement of parameters for incorporation within a process of construction site logistics optimisation. Data on vehicular movements were collected from seven sites in Cape Town. The data were used to design a flow model of material delivery and waste removal vehicular movements. Findings - The results showed that in terms of transport distribution, of all vehicle movements observed, 62.6 per cent were classified as material delivery and 26.3 per cent as construction and demolition (C&D) waste removal. This ratio approximates to 2.4 materials delivery journeys to one waste removal journey. An optimised integrated materials delivery and waste removal logistics model is presented. Practical implications - The research has highlighted the potential for integration of building materials and C&D waste logistics. Based on the ratio of 2.4: 1, up to 26.3 per cent of vehicular movements transiting sites could be eliminated by allowing material delivery vehicles to back-haul waste to points of disposal, reuse or reclamation. Originality/value - The potential use of "reverse logistics" in a construction context is demonstrated, as is the scope for the utilisation of spare capacity through the application of the reverse logistics concept and the possible reduction in unit costs and numbers of empty vehicular movements.