(Solved): Masonry Structure Design :Determine the allowable value of the midspan load, Q, as well as its value ...

Problem 2 For the masonry beam shown below with the same section as used in Example 6, a single #6 rebar is provided at an effective depth of 28 in. (instead of two rebars shown on page 18 of these notes). Using the same material properties as used in Example 6, determine the allowable value of the midspan load & as well as its value Quat beam collapse. Use I = 0.80. Q self wit. = wo = 0.279 K/ft L=12ft 0.5L * + 0.5L Example 6 The grouted clay brick masonry beam shown on the next page is to carry a 10-kip midspan load on a 12 ft span. Assuming f = 3,000 psi and F= 20 ksi, determine the required amount of steel. Solution: w = Wt. of the beam = ? Brick portim weight L = 120 x 2 (3.625) (31.625) = 191.144/ft 12x12 #k/ff3 Gront portin weight = 145 (2.75) (31.625) = 87.6th/ft lb-/ff3 144 No = Brick + Grout = 191.1+87.6 Kips/ft = 0.279 Kips/ft 1000 TON d= 28" .... *** Total section depth: 28+3.625 = 31.625" The max. B.M. : 3 11 24 M= PL + WL =2.75" 10 (12) + 0.274 (12) ² VIILSU 1104 30" -3.62511 Patok $ L=12²71 M = = 30.0+ 5.014 35. 01 K-ft To arrive at an UDL= approx. amount of - W? = 0.279k/ft steel, assume j = 0.90 and check later. 19