Energy consumption reduction in concrete mixing process by optimizing mixing time

Abstract

Mixing process plays a very important role in the concrete microstructure which defines the quality of the final product. The improvement of energy efficiency during this process can help to reduce energy consumption and production costs, without affecting product quality. However, the current concrete mixing practice using an equal mixing time for all batches of each concrete mix design may lead to unnecessary mixing time and energy waste.The present study investigates the benefit of the mixing time optimization for energy consumption reduction during the concrete mixing process. For this purpose, a reliable method based on mixing power evolution is devised to calculate the shortest necessary mixing time (stabilisation time) of each concrete batch. The batch mixing energy consumption is also determined, through the use of power consumption and the duration of mixing cycle.Experimental data obtained from 17 concrete batches of two mix designs produced in a full-scale concrete plant were analyzed to figure out the energy consumption difference between the current mixing process of a single mixing time and the one of mixing time optimization. The research results show that by optimizing the mixing time, energy consumption is reduced by about 17% in comparison with the traditional mixing process. Productivity gains are significantly marked by obtaining a reduction in average mixing time of 32%.