The beam depicted in Figure 4-1 carries a factored design (uniformly distributed) load, w*. This factored design load (w*) includes factored self-weight, factored dead load, and factored live load. Dead load and live load are applied on the entire length of the beam. The cross- section of the beam is illustrated in Figure 4-1. Use f'e = 32 MPa and fsy = 500 MPa. A Unit: mm 540 60 LA 400 2N20 W* stirrups 6400 60 Total Asc= 620mm 3N28 Total Ast=1860 mm Section A-A (Doubly reinforced beam) 3N28 Unit: mm f'c = 32 MPa fsy = 500 MPa E = 26600 MPa E, = 200 Gpa Ecu = 0.003 2N20 Figure 4-1 4.1 Find the depth to the neutral axis of a cross-section from the extreme compression fibre (dn) in positive pure bending at the ultimate state. (10 Marks) 4.2 Calculate the ultimate bending moment capacity (Mu). (7 Marks) 4.3 Based on the bending moment capacity of the section computed in the previous Question 4.2, calculate the maximum factored design load (w*) that the beam can resist. (3 Marks)