When design for a cyclic load, if in one case, the designed reliability is 0.99, what is the approximate reliability factor which should be used according to the textbook?     1.0     0.9     0.81     0.75

A tension test was performed on a specimen having an original diameter of 13.7 mm and a gauge length of 50 mm. The data are listed in the table. Load (kN) Elongation (mm) 0 11.1 31.9 37.8 40.9 43.6 53.4 62.3 64.5 62.3 58.8 0 0.0175 0.0600 0.1020 0.1650 0.2490 1.0160 3.0480 6.3500 8.8900 11.9380 Plot the stress-strain diagram. Use a scale of 20 mm = 50 MPa and 20 mm = 0.05 mm/mm. Redraw the linear-elastic region, using the same stress scale but a strain scale of 20 mm = 0.001 mm/mm. From the diagram, determine approximately the modulus of elasticity. Express your answer to three significant figures and include the appropriate units. E = Submit Part B συ = Submit Part C ☐☐ μÅ of = Value Determine the ultimate stress. Express your answer to three significant figures and include the appropriate units. Request Answer μĂ Value Request Answer Units μĂ - Value Units Determine the fracture stress. Express your answer to three significant figures and include the appropriate units. ? Units ? ?

A rigid pavement on a new interstate (3 lanes each direction) has been conservatively designed with a 12- inch slab, an Ec of 5.5 x 10 Ib/in? , a concrete modulus of rupture of 700 lb/in?, a load transfer coefficient of 3.0, an initial present serviceability index of 4.5, and a terminal serviceability index of 2.5. The overall standard deviation is 0.35, the subgrade CBR is 25, and the drainage coefficient is 0.9. The pavement was designed for 600 30-kip tandem axles per day and 1400 20-kip single axle loads per day. If the desired reliability was 90%, how long was this pavement designed to last? A 46 B 42 18 D) 37