Concreting operations: the relationship between unit costs and unit emissions

The reduction of emissions within construction is seen as an agreed direction worldwide. In this light, the paper examines unit emissions in concreting operations, and provides guidelines for their reduction. Unit emissions and unit costs are calculated through a queuing model for concreting operations where trucks cycle between a batching plant and site. A time-production constraint exists. Sensitivity-style analyses are used to evaluate the influence of truck capacity, unloading policy, pumping rate (or the equivalent for crane usage), travel time and fuel type on optimum unit emissions and unit cost. It is demonstrated that the optimum truck fleet size for unit emissions is the same as that for unit cost under a range of different operation parameters. The results indicate the most environmentally aware way to configure and manage concreting operations. The paper demonstrates that by not operating at minimum unit cost, then emissions increase. To date, the foci of studies involving concreting operations have been on production and truck dispatching. This paper is original in establishing the configuration of concreting operations for least unit emissions.