Question 5 (Mandatory) (1 point) 30 Listen 5. When a Class 2 floor is specified, what is the 28-day compressive strength. a. 3000 b. 3500 O c. 4000 Od. 4000 or higher Question 6 (Mandatory) (1 point) Listen 6. A Class 3 floor is used for O a. Residential surfaces Ob. Offices and churches O c. Exterior walks Od. Light duty industrial floors Question 7 (Mandatory) (1 point) Listen 7. What is the recommended average air content for severe exposure when using maximum %" aggregate. a. 7.5% Ob. 7% O c. 6.5% O d. 6% Question 8 (Mandatory) (1 point) Listen 8. The subgrade must be prepared by removing Oa. Grass Ob. Roots O c. Organic matter Od. All of the above