Verifi Concrete Quality Blog

Jobsite Slump Changes and Sustainability

by Verifi

How many times do you see the following scenario? The concrete arrives at the jobsite at or near the ordered slump.  The contractor looks at the concrete and immediately asks for more water or a higher slump.  Once water is added, the concrete should be mixed again.  If water is being added manually, this process may need to be repeated multiple times to get the desired slump.

This takes time, reduces concrete quality, and affects sustainability.

There are varied reasons for this practice.  For example, some contractors prefer to adjust slump themselves due to variability in slump delivered by the concrete producer.  (Verifi eliminates this need by adjusting slump in transit to ensure consistent slump at the jobsite.  It also precisely records the water added to ensure conformance with specifications.)

Verifi recently presented on this topic at the ACI Fall 2013 Convention in October 2013.  The presentation covered the prevalence of jobsite slump changes, the implications for mixture proportioning, and how Verifi can help.

Click the link below to view the presentation on “Effects of Jobsite Slump Adjustments on Sustainability”.

ACI Presentation


  • Carbon Footprint: Reduced concrete overdesign yields decrease in cement content
  • Embodied energy: Verifi reduces drum rotations, reduces fuel consumption, and improves concrete quality
  • Water use: Verifi changes human behaviors, resulting in the use of less water in the concrete mix
  • Waste content: The decreased number of rejected and returned loads saves on both fuel and potentially wasted loads
  • Human health and social well-being: Verifi helps increase job satisfaction for drivers and batchmen, while reducing conflict across the construction value chain, as wasted time, rejected loads, rip outs and repairs are dramatically reduced

Click here for more information on how Verifi brings benefits to concrete producers and their customers,  to people and the planet.