A prestressed concrete rectangular beam of size 300 × 900 mm is prestressed with an initial prestressing force of 700 kN at an eccentricity of 350 mm at midspan, stress at top fibre at midspan due to prestress alone is :
1
3.46 MPa (tension)
2
8.64 MPa (compression)
3
2.59 MPa (compression)
4
Zero