Quantification of fresh ready-mix concrete waste: Order and truck-mixer based planning coefficients

This paper reports a study of order and truck-mixer based planning coefficients used to avoid or utilise fresh concrete waste. To achieve this objective, an original calculation procedure was proposed to quantify the fresh concrete waste, and direct quantitative measurements were performed in three batching plants in Turkey. Data obtained were analysed by descriptive statistics, one-way analysis of variance, and hypothesis testing. As a result, clients may order 8.57% more of their concrete needs instead of using much wider margins to avoid over-ordered concrete. They may also reserve 8.96% of their concrete needs in other batching plants to compensate their possible extra concrete requirements. Based on these numbers, concrete amount and cost may be better estimated, and thus, the over-ordered concrete may be eliminated. Finally, leftover concrete amount was found to be 0.33% of total concrete in a truck-mixer and to be in a relationship with the number of arrivals of a truck-mixer in an order. Through these findings, potential conflicts between contractors and concrete suppliers about the amount of delivered concrete may be prevented. Also, batching plants may save concrete and benefit from recycling. Overall, natural resources and energy may be consumed less and environmental pollution may be prevented.