Gray Matter Inc. is a structural concrete contractor that has just been awarded a contract to cast and pour the beams, columns, and slabs for a five-story commercial building. The client has requested a cost analysis of two alternatives: A) The cost to perform the work under straight-time normal working conditions. B) The cost to perform the work under a combination of straight-time and a second shift. In preparing your analysis you arrived at the following numbers: 1. Under straight-time hours the workforce works at an average rate of 10.42 labor-hours/CY of concrete. This includes all tasks: forming, reinforcement, placement, and finishing. (Assume no stripping cost.) 2. The building has 32 columns at 11xllx12' per floor, 1570 LF of 9 x 10 beam per floor (assume roof deck has same design as a standard floor), and 17,250 sf of 4 slab per floor, with the slab on grade at a 6 depth. Add 15% to the total CY for the foundation. 3. The crew consists of a foreman, five carpenters, four laborers, four rodmen, two concrete finishers, one crane operator, one oiler, and an 80-ton crane. The average base cost for the crew is $98.10 per labor-hour. Assume, on-average, the entire crew is needed each workday. Page 1 of 2 CONSTRUCTION ESTIMATING 4. Second shift work rates are 7.5 hours at 8 and a 10% shift differential. 5. Assume no productivity drop. 6. The second shift requires an extra cost of $1200/day for lighting, administrative costs, etc. 7. The client estimates an opportunity cost of $5300/day for every day the building is under construction Assume 8 hour shifts. Materials and construction pattern make curing time a non-issue. Determine the best alternative and justify your answer with a narrative explanation. Also, calculate the % Differential and % LH Growth in your analysis