A concrete beam with cross section in Figure CO4-2B is simply supported over a span of 4 m. The cracking moment of the beam is 75 kN·m.
1. Find the maximum uniform load that the beam can carry without causing the concrete to crack, in kN/m.
2. Find the modulus of rapture of the concrete used in the beam.
|A. 4.12 MPa
||C. 3.77 MPa
|B. 3.25 MPa
||D. 3.54 MPa
3. If the hallow portion is replaced with a square section of side 300 mm, what is the cracking moment of the new section in kN·m?