Determination of Mineral Filler Speed Control Setting at JMF
- Enter the dry aggregate lbs./count into the Mineral Filler Summary worksheet below. This value was determined in Method A, Step 4 or Method B, Step 3 of the Calibration Summary-Determination of Gate Setting procedure.
- Determine the aggregate counts/minute at the desired production rate by running the aggregate belt for one minute and recording the total number of counts on the Mineral Filler Summary worksheet below.
- Multiply the dry aggregate lbs./count by the aggregate counts/minute to determine the total output of dry aggregate/minute of production.
- Record the percent mineral filler target from the JMF on the mix design on the Mineral Filler Summary worksheet example. This value can be found on the mix design. From the example mix design on page 108, the value is 1%.
- Multiply the dry aggregate lbs./minute by the target JMF percentage of mineral filler (in decimal form) to determine the mineral filler lbs./minute required to match the target JMF for this output of aggregate. In the example below, the value is 35.2 mineral filler lbs./minute.
- Enter the average mineral filler lbs./count from the Mineral Filler Calibration worksheet. From the example on page 29, this value is 0.25 lbs./count.
- Determine the mineral filler counts/minute by dividing the mineral filler lbs./minute by the mineral filler lbs./count. In the example below, the value is 141 mineral filler counts/minute.
- Adjust the mineral filler feeder to achieve 141 mineral filler counts/minute.
Inspector’s Note: Over the course of the job, occasionally verify that the mineral filler speed control and aggregate gate settings match that which was determined during calibration. If a variable speed constant displacement pump was used, verify that the flow rate setting used during calibration remains unchanged.