Refer to the optimal reinforced concrete beam design example. Reformulate the mathematical...

Refer to the optimal reinforced concrete beam design example. Reformulate the mathematical programming model, including the cost of formwork, and under the following conditions:

concrete:   4,00 psi normal weight at $25/yd3

steel:     A615 Grade 60 at $500/ton;

formwork:   pine at $3.00/ft2 contact area;

imposed moment: 300 kip-feet

steed placement: two rows bottom (total beam height –d + 4.0 inches): and

(a) Verify that the following solution satisfies your model.

(b) Based on the model outcome, if one wanted to invest in research to reduce the cost of such beams, where would attention be most productively directed?

(c) What do you conclude about the sensitivity or the optimal beam design to inclusion of the cost of formwork in this case?