Point Loads from Beams

In a reinforced concrete framed building, the suspended beams and slabs are cast monolithically so that there is no weak joint at the beam slab interface.

The picture below shows the beams only for an RC beam and slab system. In loading, the secondary beam is assumed to sit on the two primary beams. Therefore the secondary beam has to be loaded first. The two support reactions from the secondary beam (left and right) are taken as point loads acting onto the primary beam.

Primary and secondary beams in an RC beam system (click to enlarge).

The structural analysis software will automatically factor the loading. Loading input into the software has to be unfactored.

In Malaysia, the reinforced concrete code used is BS 8110 and the load factors are:
Design Load = 1.4 G_k + 1.6 Q_k

where G_k is the Dead Load and Q_k is the Live Load.

The United Kingdom will be transitioning from BS 8110 to Eurocode 2 (EC 2). The original date set for the full implementation of EC 2 in the U.K. has been shifted from 2006 to 2008 and then it was shifted again to 2010. In the ISO-TC 71 – Concrete, Reinforced Concrete and Prestressed Concrete meeting in Istanbul in September 2004, which was attended by the author representing Malaysia, EC 2 has been accepted as to comply with ISO standards.