A novel approach to improve quality of delivered concrete using slump estimations of the ready-mixed concrete (RMC) truck mixer

Abstract

Slump is an effective parameter in concrete quality control. It does affect the ease with which concrete can be transported, placed, and screeded, and is a relatively reliable indicator of batch-to-batch variability. Accordingly, monitoring the concrete Slump and fluidity while transporting is a proper response to many concerns in the concrete industry. Despite the aging of the existing concrete trucks, determining the relationship between the data obtained from the truck mixer and the slump, requires careful study of the components of the truck's drum. However, an advanced model for determining the slump of fresh concrete in a transporting truck, has not been presented. In this study, the relationship between a concrete Slump and hydraulic oil pressure at different drum rotation speeds and different weights has been investigated through a suitable regression model (linear or power) regarding its trendline. Moreover, using the Computational Fluid Dynamics (CFD), numerical slump model, and drum rotation, and the output power was investigated. The results clarified that by increasing the concrete weight from 6608 to 16500 kg, the hydraulic oil pressure increases 10 bar approximately. Also, changing the drum's rotation speed from 5 to 20 rpm increases the hydraulic oil pressure by 22%, while the changes in the mix design do not have much effect on the hydraulic oil pressure. Based on the results obtained for the relationship between slump value and measurable parameters in the truck mixer, a new approach to improving the quality the ready-mixed concrete (RMC) in construction projects is presented.