Concrete slump monitoring technology

In 2011, we rolled out concrete slump monitoring technology across all 130 large mixer trucks in the Central region and at all the region's concrete plants.

Following the successful trial of the monitoring system at three trial plants in the North West and installation in 15 trucks, which are fully operational, we continued rolling out the innovative technology.

When a team from contractor Extrudakerb sought to replace the M18’s metal central reservation barriers near Doncaster, South Yorkshire, with concrete ones, Tarmac supplied the concrete from its Aston, Sheffield plant. Our concrete slump monitoring technology offered a practical solution that improved the accuracy and efficiency of concrete production.

The technology works by accurately measuring and controlling concrete slump – the concrete’s consistency – at all stages of the process, from the time the concrete is loaded onto the truck until the point it is discharged, by calculating hydraulic pressure within the drum. To calculate the slump, the system records drum revolutions, drum speed and hydraulic pressure used to turn the drum. Water is added automatically to reach target slump, if required. A digital display on the side of the truck shows when the concrete has reached the specified slump and helps the driver ensure that the concrete’s consistency is exactly right.

At the end of the delivery, the truck mixer returns to the plant where the data is automatically saved to the plant computer. This recorded data enables better batching and effective performance management of drivers and trucks.

Previously, technicians had to perform a manual slump test, which made it difficult to tell if extra water had been added to the concrete during transport and delivery. Extrudakerb was so impressed with the concrete slump monitoring technology that it awarded Tarmac the contract to supply the concrete for the second phase of the job on the M18 near Doncaster. We have also won other jobs such as the contract for the M180 central reservation barrier replacement.

Benefits of the new, more controlled method include cost savings, improved concrete quality and increased customer satisfaction, with fewer complaints or returns. Andy Clarke, change agent, who is project managing the implementation across the Central region, commented, “We’ve identified around £250,000 (of savings) per annum in Central alone. By controlling and reducing the variability of water we can improve the quality and vastly reduce customer complaints and returns.”

Achieving high standards with the concrete slump monitoring technology gives us a real competitive edge and we plan further roll-out across other regions in 2011.