TANK MEASUREMENT
& ASPHALT BINDER CONTENT DETERMINATION
GENERAL
This Instructional Memorandum covers the procedures used by the contracting authority to determine: (1). The quantity of asphalt binder incorporated in a project, and (2) the asphalt binder content of individual production runs of asphalt mixtures. This IM also provides instruction for completing Form #E216 (#M216). The plant inspector is referred to the applicable specifications and instructions for the specified tolerances and measurement frequencies.
Tables are furnished for computing quantities of materials stored in standard horizontal cylindrical tanks, and for correcting volumes to standard temperature. The plant inspector is responsible for checking to see that appropriate gauging tables and calibrated sticks are available prior to beginning work on a project. The contractor is required to furnish the calibrated measuring sticks, and gauging tables, for all storage tanks.
PROCEDURES
Refer to example, Form #E216 (#M216)
PROJECT NO.
Enter the project number listed on the project plans.
CONTRACT ID
Enter the county listed on the project plans.
DATE
Enter the date the tank measurement is recorded.
REPORT NO.
Enter the report number of the Daily HMA Plant Report, which reflects the daily virgin asphalt binder tank stick information.
START OF PERIOD
TANK NO., TANK IDENTIFICATION
Each asphalt binder storage tank shall be identified by a number or letter and listed on the form. If a separate working tank or surge tank is provided, it will be necessary to establish a uniform procedure for determining the quantity or level or material in the tank. It is recommended that the plant inspector arrange with the contractor to maintain a uniform storage level in the surge tank.
Enter the tank number for each tank being used each day of production. Four tanks may be used on a given day and recorded on a single sheet.
TIME
Enter the beginning time for each tank that is measured each day of production.
TANK CAPACITY (A)
The capacity of each tank depends upon its dimensions. The capacity of standard cylindrical tanks may be computed by determining the length and radius from actual measurements. All dimensions must be inside measurements. The volume of a cylindrical tank is obtained by multiplying the length of the tank (L), by the radius of the tank (˝ the diameter) squared, by the constant pi (3.141592). That is, volume (V) = L(pi)r2. When measurements are obtained in meters, convert m3 to liters by multiplying by 1,000. When measurements are obtained in feet, convert ft.3 to gallons by multiplying by 7.48 gal./ft.3. The contractor is required to furnish the manufacturer's data for nonstandard tanks. The contractor should not be permitted to allow the level of the asphalt cement to drop below the level of the heating coils, because accurate measurements cannot be made when the cross section of the storage area varies.
Enter the tank capacity in gallons (liters) for each tank being used each day of production.
OUTAGE (PERCENT OF DIAMETER) (B)
The number entered in this row is obtained from the actual tank measurement using the calibrated stick provided for each tank. The measurement is made by placing the stick through the designated tank hatch down to the level of the stored material. The percent outage is read from the stick at the reference elevation, which is normally the inside shell wall. The reference elevation can be checked by placing the stick at the full elevation and checking to see that the zero percentage line and the top of the tank coincide. When the tank shell is full, the outage percentage is zero, and when the tank is empty the outage is 100%.
When non-standard tanks are used, the manufacturer's tables, measuring sticks, and instructions must be followed.
Enter the outage tank stick reading for each tank when the T104 tables are used. If a direct reading measurement is made for a tank stick reading, leave this row blank.
INNAGE (PERCENT OF CAPACITY) (C)
Enter the FILLED PERCENT OF CAPACITY figure from the T104 tables, which coincides with the Outage (Percent of Diameter) (B) figure listed above for each tank used. If a direct reading measurement is made for a tank stick reading, leave this row blank. Refer to the manufacturer tables for non-standard tanks.
DIRECT READING (D)
Enter the direct reading measurement figure that is calculated for each tank being used. If you do not use a direct reading tank measurement stick, leave this row blank.
TEMPERATURE (E)
The temperature of the asphalt binder in each tank must be determined at the time the measurements are made. This is done by lowering a maximum registering thermometer to the approximate center of the asphalt cement stored. The thermometer must be shook down to a temperature less than that of the asphalt cement in the storage tank and must be allowed to adjust to the temperature of the stored material. From 3 to 5 minutes should be allowed for this adjustment. Thermometers mounted permanently in the storage tanks by the manufacturers may be used if they agree with the thermometers checked by the Central Laboratory.
Enter the Fahrenheit (Celsius) temperature at the time each tank is measured.
T102 TEMPERATURE CORRECTION FACTOR (F)
The volume of asphalt in the tank at the time of measurement must be corrected to 60°F (15°C). Refer to tables T102 or T103 to obtain the appropriate four-digit correction factor which corresponds to the Celsius (Fahrenheit) temperature recorded for each tank used.
CORRECTED GALLONS (LITERS) (G)
Enter the corrected gallons (liters) at 60°F (15°C) for each tank being used by multiplying rows A, C, & F or D & F, depending on which method is used to measure the asphalt. Divide result by 100 when C is expressed as a whole number percent. This is the standard temperature at which pay quantities are determined.
TOTAL CORRECTED GALLONS (LITERS) (H)
Enter the total corrected gallons (liters) by adding the corrected gallons (liters) figures for each tank being used.
TOTAL ASPHALT BINDER ADDED
TOTAL POUNDS (KILOGRAMS) (I)
This space provides for entering the total quantity of asphalt added during the production run. Care must be exercised to ensure that weight (mass) tickets are obtained for each load placed in the storage tank during the production run. Each shipment ticket should be logged in the plant book, with the appropriate date and unloading time. The weight (mass) is converted to corrected gallons (liters) at 60°F (15°C) by dividing by the weight (mass) per gallons (liters) coefficient provided by the supplier. Quantities added shall be certified or determined at the job site.
Enter the total pounds (kilograms) added to each tank being used.
WEIGHT (MASS) PER GALLON (LITER) (J)
The asphalt binder supplier provides the average weight (mass) per gallon (liter). If asphalt binder from different sources has been used during the production run, it is necessary to compute a weighted average weight (mass) per gallon (liter) for the total quantity used. If emulsified asphalt or cutback asphalt is being used, it is necessary to reduce the mass of the diluted material to asphalt residue. The quantity of asphalt residue incorporated is determined by multiplying the total mass of emulsion or cutback by the percent residue value furnished by the supplier.
Enter the weight (mass) per gallon (liter) listed on the shipment tickets. The weight (mass) per gallon (liter) cannot change on a given day of production.
TOTAL CORRECTED GALLONS (LITERS) (K)
Enter the total corrected gallons (liters) added during the day by adding the (I) row figures together and dividing by the (J) figure.
END OF PERIOD
TIME
Enter the ending time for each tank that is measured each day of production.
TANK CAPACITY (L)
Enter the tank capacity in gallons (liters) for each tank being used each day of production.
OUTAGE (PERCENT OF DIAMETER) (M)
Enter the outage tank stick reading for each tank when the T104 tables are used. If a direct reading measurement is made for a tank stick reading, leave this row blank.
INNAGE (PERCENT OF CAPACITY) (N)
Enter the FILLED PERCENT OF CAPACITY figure from the T104 tables which coincides with the Outage (Percent of Diameter) (B) figure listed above for each tank used. If a direct reading measurement is made for a tank stick reading, leave this row blank.
DIRECT READING (O)
Enter the direct reading measurement figure that is calculated for each tank being used. If you do not use a direct reading tank measurement stick, leave this row blank.
TEMPERATURE (P)
Enter the Fahrenheit (Celsius) temperature at the time each tank is measured.
T102 TEMPERATURE CORRECTION FACTOR (Q)
The volume of asphalt in the tank at the time of measurement must be corrected to 60°F (15°C). Refer to tables T102 or T103 to obtain the appropriate four-digit correction factor which corresponds to the Fahrenheit (Celsius) temperature recorded for each tank used.
CORRECTED GALLONS (LITERS) (R)
Enter the corrected gallons (liters) at 60°F (15°C) for each tank being used by multiplying rows L, N, & Q or O & Q, depending which method is used to measure the AC. Divide result by 100 when C is expressed as a whole number percent. This is the standard temperature at which pay quantities are determined.
TOTAL CORRECTED GALLONS (LITERS) (S)
Enter the total corrected gallons (liters) by adding the corrected gallons (liters) figures for each tank being used.
CALCULATIONS
TOTAL CORRECTED GALLONS (LITERS) USED (T)
Enter the total corrected gallons (liters) used each day of production by adding (H) and (K), then subtracting (S).
WEIGHT (MASS) PER GALLON (LITER) (U)
Enter the four-digit figure listed in the (J) row from above.
TOTAL POUNDS (KILOGRAMS) OF BINDER USED (V)
This number is obtained by multiplying (T) by (U).
TOTAL POUNDS (KILOGRAMS) OF MIX PRODUCED (W)
Enter the total pounds (kilograms) of mix produced by the plant each day.
The total pounds (kilograms) of mixture are determined by adding the net weight (mass) of all the scale tickets. This total includes all mixture produced, including rejected, wasted, or commercial loads. Mixtures, such as cold mixes, which contain moisture, must be corrected for the moisture content.
TOTAL POUNDS (KILOGRAMS) OF MIX WASTED (X)
Enter the total pounds (kilograms) of mix wasted during the day. This figure includes road waste, plant waste and other mix, which was wasted, sold rejected or otherwise disposed of. All mix so wasted should be weighed, if at all possible. It may be necessary to estimate small quantities of waste in some cases.
TOTAL POUNDS (KILOGRAMS OF BINDER WASTED (Y)
This number is determined by multiplying the percent asphalt (Z) by the total pounds of mix wasted (X). This quantity will not be included in the project pay quantity total.
NET TONS (MEGAGRAMS) OF ASPHALT BINDER INCORPORATED IN THE PROJECT
This is the net quantity of asphalt binder for which the contractor is eligible to receive pay.
This number is obtained by subtracting (Y) from (V) and then dividing by 1000 for Megagrams or 2000 for Tons. THIS FIGURE SHALL BE GIVEN TO THE ROAD INSPECTOR EACH DAY.
NET TONS (MEGAGRAMS) OF MIX INCORPORATED IN THE PROJECT
This number is obtained by subtracting (X) from (W) and then dividing by 2000 for Tons or 1000 for Megagrams. This is the net quantity eligible for payment. THIS FIGURE SHALL CORRELATE WITH THE ROAD FIGURE EACH DAY.
PERCENT VIRGIN ASPHALT BINDER, BY TANK MEASUREMENT (Z)
This percent virgin binder is obtained by dividing (V) by (W) and multiplying by 100.
This percentage is obtained by dividing the total net pounds (kilograms) of asphalt binder incorporated (V) by the total net pounds (kilograms)of mix produced (W). The plant inspector is, at this point, directed to refer to appropriate specifications to determine if this percentage is within the allowable tolerance.
COMMENTS
Self-explanatory:
ALL COMPUTATIONS SHOULD BE CHECKED THOROUGHLY AND PROMPTLY; ANY CORRECTIONS SHOULD BE REPORTED TO THE CONTRACTOR AND RECORDED ON THE DAILY REPORT FORMS. UPON COMPLETION OF THE PROJECT THE COMPLETED FORM SHALL BE INCORPORATED IN THE RESIDENT OR COUNTY ENGINEER PROJECT FILE.
