1. A tensile-reinforced beam has b = 12 in. and d = 20 in. to the center of the bars, which are placed all in one row. If fy = 60,000 psi and fc’ = 5000 psi, find the nominal flexural strength Mn for (a) As = two No. 8 bars, (b) As = two No. 10 bars, and (c) As = three No. 8 bars.
2.Five organic compounds (A through E) were tested for suitability for biofiltration control. Their retardation ratios (in order) were 5, 8, 13, 21 and 34. Which of these is most suitable for a biofilter and why?
3. Find the concrete cross-section and steel area required for a simply supported rectangular beam with a span of 20 ft that is to carry a computed dead load of 1.3 k/ft and a service live load of 2.25 k/ft. Material strengths are fc’ = 5000 psi and fy = 60,000 psi.