12–44. When performing single–surface treatment  operations,  you  should ensure  aggregates  cover  the bituminous material within how many minutes after spraying? 1 1   minute 2. 10  minutes 3. 30  minutes 4. 60  minutes 12-45. To  compute  the  amount  of  aggregate per square yard required for a single-surface  treatment,  you  use what rule of thumb? 1. 10 to 15 pounds per square  yard 2. 15 to 25 pounds per square  yard 3. 25 to 30 pounds per square  yard 4. 30 to 35 pounds per square  yard 12–46. What size of aggregate is used on the second layer of a multiple- surface   treatment? 1. 1/2 the size of the previous  layer 2. 3/4 the size of the previous  layer 3. 1 1/2 the size of the previous  layer 4. 1 3/4 the size of the previous  layer Learning  Objective: Recognize the  principles  and  components of paving equipment. 12-47. Of  the  following  disadvantages, which  is  associated  with  the  use of  a  tailgate  spreader? 1. The  truck  must  be  operated in  reverse 2. A  reduction  in  steering control of the truck 3. A  reduction  in  the  operational speed of the truck 4. All of the above 12-48. Which  of  the  following  components is NOT part of an asphalt distributor   unit? 1. Insulated  storage  and  heating tank 2. Open-flame heating system and  asphalt  pump 3. Low-pressure  air  blower and  circulating  and  spraying system 4. Twin-shaft pugmill that thoroughly  mixes  the  material 12-49. Asphalt  heating  operations  can  be performed  while  the  distributor truck is traveling to the jobsite. 1. True 2. False 12-50. When  spraying  bitumen  with  a distributor  truck,  the  application rate is controlled by the length of the spray bar, the pump output, and what other factor? 1. Amount  of  material  carried 2. Existing  ground  material 3. Forward speed of the distributor  truck 4. Amount of turns on the main  control  valve 12-51. When  operating  a  distributor truck, the spray bar should be set high enough for the road surface to receive triple coverage. However,  under  heavy  wind conditions  or  depending  on  the nozzle spacing, it may be necessary to lower the spray bar more  to  ensure  the  surface receives  which  of  the  following coverages? 1. Single 2. Double 3. Triple 4. Half 12-52. When  heating  bitumen  in  a distributor truck, you should NOT use  which  of  the  following  fuels? 1. Kerosene 2. Fuel  oil 3. Diesel 4. Gasoline 93