37 Prestressed Concrete Beam Camber – BT84 k f = 5 = 5 = 0.625 1+f c 1 + 7.0 k td = t = 14 = 0.30 61 – 4f c + t 61 – (4)(7.0) + 14 ε sh = (1.10)(1.02)(0.625)(0.30)(0.48x10 -3 ) = 0.00010098 Shortening from shrinkage = (1800)(0.00010098) = 0.18 inches Neglect effects of strand relaxation Total shortening at 2 weeks = 1.03 + 0.40 + 0.18 = 1.61 inches