Chapter 14, Problem 14.1P

Consider the specifications for an asphaltic concrete mixture and the results of a sieve analysis below. Coarse aggregates: Fine aggregates: Filler: 60% 35% 5% Percent of Weight of Aggregate or Filler Passing Sieve Designation Retained on Sieve Designation Coarse Aggregate Fine Aggregate Mineral Filler 3/4 in. (19 mm) 1/2 in. 6 1/2 in. (12.5 mm) 3/8 in. 15 3/8 in. (9.5 mm) No. 4 50 - No. 4 (4.75 mm) No. 10 20 1 No. 10 (2 mm) No. 40 (0.425 mm) No. 40 9 35 - No. 80 31 40 No. 80 (0.180 mm) No. 200 (0.075 mm) Total No. 200 - 33 - - 25 35 100 100 100 Determine the proportion of different aggregates to obtain the required gradation. Percent of Total Weight of Mixture Passing Sieve Designation Retained on Sieve Designation Coarse Aggregate Fine Aggregate 3/4 in. (19 mm) 1/2 in. (12.5 mm) 3/8 in. (9.5 mm) 1/2 in. 3/8 in. No. 4 No. 4 (4.75 mm) No. 10 No. 10 (2 mm) No. 40 No. 40 (0.425 mm) No. 80 No. 80 (0.180 mm) No. 200 No. 200 (0.075 mm) Total Need Help? Read It Mineral Filler Total 100

Results obtained from laboratory tests on a sample of RC-250 asphalt cement are given. Determine whether the properties of this material meet the Asphalt Institute specifications for this type of material; if not, note the differences. (For each specification, enter the minimum acceptab value in the same units as used in the test results.) • Kinematic viscosity at 140°F (60°C) = 230 centistokes • Flash point (Tagliabue open cup) = 89°F • Distillation test where distillate percent by volume of total distillate to 680°F (360ºC) • To 437°F (225°C) = 27% • To 500°F (260°C) = 69% • To 600°F (316°C) = 72% • Residue from distillation to 680°F (360°C) by volume percentage of sample by difference • Tests on Residue from Distillation: • Ductility at 77°F (25°C) = 92 cm • Absolute viscosity at 140°F (60°C) = 620 poises ⚫ Solubility = 90% Property Kinematic Viscosity = 74% Specification Test Results Were Specifications Met? centistokes 230 centistokes ---Select--- ✓ Flash Point °F 89°F…

Problem 2 Two machines produce rivets for a factory job. The number of sub-standard rivets per hour by the two machines are random variables, denoted by X1 and X2. The bivariate PMF of X1 and X2, Px,x,(x1,x2), is given in the table below. X2=0 X2=1 X2=2 X2=3 X₁-0 0.07 0.05 0.02 0.01 X₁ =1 0.05 0.16 0.12 0.02 X₁ =2 0.02 0.12 0.17 0.05 X₁ =3 0.01 0.01 0.05 0.07