**Situation**

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.

A. 35.2 |
C. 33.3 |

B. 37.5 |
D. 41.8 |

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?

A. 71.51 |
C. 78.69 |

B. 76.58 |
D. 81.11 |

**Answer Key**