to find rate of application for asphalt or aggregate
W=
9xT LxR
to find width of roadway
T=
T R
L xWxR 9
to find total gallons of asphalt or total pounds of aggregate (to convert pounds to tons, divide pounds by 2000)
x Rate of aggregate
to find pounds of aggregate needed to cover a given load
Definitions: L = Length of spread in feet R = Rate of application (asphalt in gallons per sq. yd. or aggregate in lb. per sq. yd.) W = Width of roadway T = Total gallons or pounds Formulas for Surface Treatment – Determining Distributor Speed Sf =
9 x Sbo WxR
to find feet per minute
Sm =
9 x Sbo 88 x W x R
to find miles per hour
Definitions: Sf = Speed in feet per minute Sm = Speed in miles per hour Sbo = Spray-bar output in gallons per minute W = Width of roadway in feet R=
Rate of application in gallons per square yard HMA-8-1
Hot Mix Paving Problems 1.
The Contractor has uniformly applied 610 gallons of undiluted CRS-1 emulsion to a section of roadway for a tack coat. The tack covers 5250 linear feet in length at a width of 11 feet. What is the application rate of the tack coat? _______________ gal/yd.2 Does this meet specification?
2.
The Contractor has uniformly applied 3320 gallons of undiluted CRS-1 emulsion to a section of roadway for a tack coat. The tack covers 29,040 linear feet length at a width of 12 feet. What is the application rate of the tack coat? _________________ gal/yd.2 Does this meet specification?
HMA-8-2
3.
The Contractor has uniformly applied 2154 gallons of undiluted CRS-1 emulsion to a section of roadway for a tack coat. The tack covers 38,016 linear feet in length at a width of 12 feet. What is the application rate of the tack coat? _________________ gal/yd.2 Does this meet specification?
4.
Using the information below: A) Calculate the linear feet this truckload of HMA should cover at the specified application rate. ________________ linear ft. B) How many linear feet will each ton of HMA pave? _________________ linear ft/ton Application Rate = 185 lb./yd2 Total weight shipped = 33,135 lb. Pavement width = 11 feet
HMA-8-3
5.
Using the information below: A)
Calculate the linear feet this truckload of HMA should cover at the specified application rate. _____________________ linear ft.
B)
How many linear feet will each ton of HMA pave? __________________ linear ft/ton
Application Rate Total weight shipped Pavement width
6.
= 165 lb./yd2 = 127,580 lb. = 24 ft.
Using the information below: A) Calculate the linear feet this truckload of HMA should cover at the specified application rate. _____________________ linear ft. B) How many linear feet will each ton of HMA pave? _____________________ linear ft/ton Application Rate Total weight shipped Pavement width
= 158 lb./yd2 = 46,778 lb. = 12 ft.
HMA-8-4
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HMA-8-5
Placement Limitations Section 315.04 of the Road and Bridge Specifications provide for the placement limitations of hot mix asphalt. Table III-2, also called the nomograph, is used to determine the minimum laydown temperature for a mix at a specific rate of application using either the 8-minute maximum breakdown rolling time (using two rollers) or the 15 minute maximum breakdown rolling time (using 1 roller), at a specific base temperature.
HMA-8-6
7.
A load of IM-19.0A arrived at the project to be placed at 220 lb./yd.2 with one breakdown roller on the job and a base temperature of 50°F, what is the minimum laydown temperature? A. B. C. D.
8.
A load of SM-12.5A arrived at the project to be placed at 165 lb./yd.2 with two breakdown rollers on the job and a base temperature of 40°F, what is the minimum laydown temperature? A. B. C. D.
9.
300°F 318°F 287°F 307°F
A load of IM-19.0A arrived at the project to be placed at 190 lb./yd.2 with two breakdown rollers on the job and a base temperature of 52°F, what is the minimum laydown temperature? A. B. C. D.
11.
330°F 338°F 250°F 296°F
A load of SM-12.5A arrived at the project to be placed at 185 lb./yd.2 with one breakdown roller on the job and a base temperature of 45°F, what is the minimum laydown temperature? A. B. C. D.
10.
250°F 304°F 295°F 353°F
308°F 338°F 281°F 274°F
The 8 minute maximum breakdown rolling time is specified when 2 or more rollers are used in breakdown rolling. A. True B. False
