ABSTRACT
The bending moments on simple beams and slabs that are freely supported on two supports or cantilevered can be calculated from simple statics. This chapter discusses the determination of the bending moments on continuous slabs, beams and frames. In some cases, the beams are designed to act monolithically with the supporting columns, the structural frame then being analysed as a whole. For the purpose of calculating bending moments, BS8110 defines the effective span of a continuous member as the distance between the centres of the supports or from the face of a cantilever to the centre of its support. In flanged beams, it is generally an advantage to reduce the support moments as much as possible, since the area of concrete in compression in the rib at the support is so much less than that in the flange at midspan. The position and magnitude of the maximum positive bending moments are readily calculated for beams carrying concentrated loads.
