Verifi Concrete Quality Blog

Posts Tagged ‘batch ticket’

Concrete Batch Tickets—Explained

by Verifi

Every load of concrete comes with a concrete batch ticket. Here’s what to look for to understand what’s in your concrete at the time of batching.

Let’s start with this example ticket.  Since there is no required format, tickets may contain more or less information.

concrete batch ticket verifi

© Verifi LLC

Tickets show basic information about the purchase, such truck number, ticket number, batch time and date, mix design identity, customer, and job location.

Some tickets show batch weights. Concrete producers invest significantly to create proprietary mixture proportions, so they may choose to not provide batch weights. This ticket shows the design quantity of each material based on saturated surface dry aggregates (SSD), followed by the amount required for 10 yd3 based on aggregates in their actual moisture condition.

Most batch software programs, including the one used here, use apparent aggregate moisture content (total moisture minus absorption capacity), which is simpler but less accurate than using the total moisture content. In most cases, the error is inconsequential.  In this case, the aggregates have greater moisture than the SSD condition, so the amount batched must be increased.

The required water content is reduced by all other sources of water; that is, the free moisture in the aggregates as batched, the water estimated to be remaining in the drum before loading, and the amount of water trimmed by the batch operator. Note that water can be shown in gallons or pounds depending on whether it is measured by volume or weight. In this load, only 64% of the design water was added directly in the batch plant.

The actual amount batched varied slightly from the required quantity. This can occur, for example, due to aggregate bin gates or water valves closing too soon or late.

The amount of water is summarized at the end.  In this case, 30.9 gal of water was not added at batching and is available to be added on the truck. This water is available intentionally to account for slump loss to the jobsite.

Verifi interfaces with the batch software to obtain the actual amount of water batched and the amount remaining to be added after batching. Verifi can automatically add this water to maintain the target slump in transit. By using this number, Verifi can ensure the maximum design water content is not exceeded.

 

Verifi Feature: Ticketed Slump Override

by Verifi

Is it OK for the slump of the concrete to not match the slump on the batch ticket?

Yes…in some cases.

For example, on a pumped job, the ticket may indicate the slump at the point of placement; that is, the end of the pump line. Due to slump loss during pumping, the concrete should be discharged from the truck at a slump greater than shown on the ticket.  In this example, Verifi would need to manage the slump to a target greater than the ticketed slump.

In another example, the contractor orders one slump but after the first load quickly realizes he needs a higher slump.  The concrete producer needs to override the slump on loads that are already ticketed so Verifi can start managing to the higher slump target.

Verifi can accommodate these cases with the Ticketed Slump Override feature. With this feature, the concrete producer enters the order number, date, location, mix code, and new slump for the override. Verifi will then use the new target slump, even if different from what is shown on the ticket. Verifi typically receives the ticketed slump through an interface with the batch plant software.

concrete slump ticket

A new override has to be entered each day, as job conditions affecting the override can change daily. The override can be turned on or off at any time.

Verifi keeps a record of all ticketed slump overrides. Access can be restricted to Verifi users with authority to change the slump.

ticketed slump override

The Ticketed Slump Override feature enables Verifi to adjust to the new slump in transit, which helps save time at the jobsite and avoids imprecise manual adjustments of slump.

Verifi customers can contact their Business Analyst to get started using the Ticketed Slump Override.

Eight Sources of Water in Concrete

by Verifi
Concrete batch tickets typically have the water added in the plant neatly printed on the ticket. What may surprise you is that there are actually multiple sources of water. For the total water content in the concrete to be correct, the concrete producer must carefully control and document each source. Here are eight potential sources of water:
  1. Water from cleaning the drum after the prior load 

    Some batch software programs let users input the amount of water in the drum prior to batching. However, measuring this water accurately is a challenge. So, in most cases, the driver should reverse the drum after washing and before loading to empty out the remaining water.

  2. Aggregate free moisture

    Aggregate free moisture can account for 10 to 40% of total water. That’s why aggregate moisture measurement is crucial.

  3. Batch water

    This water is measured by volume or weight. It may be heated or chilled. Given all the other water sources, it accounts for only 60 to 90% of total water.

  4. Admixtures

    Most admixtures contain water in addition to their active ingredients. Given typical volumes of admixture, this water content is very small, but easily and accurately accounted.

  5. Ice

    One pound of ice = one pound of water.

  6. Wash down water 

    After batching, the driver needs to clean any material that got on the hopper and the top of the drum during batching. This prevents material from building up and hardening on the truck. The driver simply “washes down” this material into the drum. Usually only a few gallons of water are needed.

  7. Driver water

    If the slump after batching or at the site is less than target, the driver may add water. This water can be measured with an electronic meter, or more commonly with the sight tube on the truck water tank. However, don’t assume that the sight tube shows all water added. Some water may be used for other purposes—such as washing the truck. Any water added before the tank is filled will be missed on the sight tube. Water can also be added from a fixed hose at the plant used to wash the truck.

  8. Contractor water

    The contractor may request a higher slump than ordered. When this happens, it’s actually not uncommon for the contractor to walk over to the truck and open the water valve leading to the drum, sometimes without the driver or inspector even seeing.

Verifi helps concrete producers control each of these sources of water and provide documentation to inspectors, engineers, and owners. Learn more at VerifiConcrete.com.