How to reinforce a girder with a span of 5 meters?

1, concrete strength grade C25, beam section 240×500, longitudinal reinforcement grade II steel du(HRB335), stirrup grade I steel (HPB235). ?

2. Two longitudinal steel bars with a diameter of 10mm are arranged at the upper part of the beam; Five longitudinal bars with a diameter of 25 in the lower part of the beam are arranged in two rows, three in the lower row and two in the upper row; Four waist tendons with a diameter of 10mm (two on each side of the beam) are set on the beam side, and they are bound with lacing with a diameter of 6mm and a spacing of 300 mm; The stirrup is 8mm in diameter and the spacing is 150. Arrange the entire length of the beam.

Beams are generally equipped with the following kinds of reinforcement: longitudinal reinforcement, stirrup, flexural reinforcement, vertical reinforcement and longitudinal structural reinforcement.

1, longitudinal reinforcement

Generally, the number of longitudinal steel bars should not be less than two (when the Liang Kuan is less than 100mm, it can be one). When the strength grade of concrete is greater than or equal to C25, the thickness of protective layer is 25mm.

2. stirrup

Stirrup is mainly responsible for shear force, with a diameter of not less than 6mm and a stirrup diameter of not less than d/4(d is the maximum diameter of longitudinal compressive reinforcement).

3, bending steel bar

The angle between the bending steel bar and the beam axis (called bending angle) is generally 45; When the beam is 800 mm high, the bending angle is 60.