1. On a set of engineering drawings (Drawing no. S-05 Slab plan - first floor) for a project ("Central supermarket") on which you are working, a reinforced concrete floor slab spans over a grid of steel beams spaced at 6 metres in each direction. The drawings say that the slab is 120 mm thick and has N20 bars running in two directions both top and bottom of the slab (two-way spanning and continuous). In the specifications, cover to the reinforcement is noted as 30 mm top and 20 mm bottom and the concrete strength is noted as 32 MPa. The slab is an internal slab with no external exposure.

Although preparations for this stage of the job are some weeks away yet, compose two points that you wish to discuss with the engineer responsible for the design to address your concerns that there may be an error.

Please explain whether the cover to the reinforcements and the concrete strength MPa are accurate what changes need to be made.