Part 2 Draw a circle on the correct answer: (18 points) In problems (1 and 2), the following data are assumed; modulus of elasticity of concrete =4x 10 psi. Poisson ratio of concrete 0.15, subgrade modulus (k)-50 pci, coefficient of thermal expansion of concrete=5X10-in./in./F. X 1. How much the curling stress in an 8-in. slab during the day under a temperature gradient of 3'F per inch of slab at an interior point? b. 200.56 psi a. 211.03 psl c. 198 psl b. 200.56 psi 20 ft x 12ft a. 211.03 psi 2. How much the curling stress in an 8-in. slab during the day under a temperature gradient of 3F per inch of slab at an edge point? c. 198 psi d. 150.03 psi d. 150.03 psl