4.22 Figure P4.22 shows details of a concrete masonry wall having an 8 ft wide open- ing. The wall is 8-in. thick (nominal) and grouted solid (medium weight units grout weight 140 lb/ft³). The reinforced masonry over the opening is to be utilized as lintel. The wall supports two superimposed concentrated loads 8 kips each (40 percent dead load and 60 percent live load), transferred to it as reactions from roof trusses spaced at 8 ft o.c. The parapet extends 2 ft 8 in. above the roof level as shown in the figure. Determine the tensile reinforcement (Grade 60) required for the lintel if f=1500 lb/in.². DESIGN OF REINFORCED MASONRY BEAMS Top of parapet FIGURE P4.22 R 8' T + 8 ft (clear) AV T R Roof level 2-8" 4' 12' 4.139