YS-RCL-BS-04

BENDING, SHEAR AND PUNCHING (SLAB)

Problem

Design a grade 45 reinforced concrete slab section subjected to 9kNm bending moment, 6kN shear force and 70kN concentrated load acting over an area of 50mm x 50mm. The slab thickness is 115mm and cover to reinforcement is 25mm.

Solution

1. Determine the diameter and spacing of main reinforcement in slab.
2. Calculate the effective depth to reinforcement, as well as the total area of reinforcement.
3. Determine the bending moment resistance provided by longitudinal reinforcement based on cl.3.4.4.4, BS8110-1:1997.
4. Compare the design bending moment with the calculated bending moment resistance.
5. Determine the shear force resistance provided by longitudinal reinforcement, referring to Table 3.7, Table 3.8 & cl.3.5.5.2, BS8110-1:1997.
6. Compare the design shear force with the calculated shear force resistance.
7. Calculate the design punching shear stress by dividing design load to the loading area, as per cl.3.1.3.1, BS8110-1:1997.
8. Determine the punching shear resistance provided by longitudinal reinforcement, referring to cl.3.7.7.2, cl.3.7.7.3 & cl.3.7.7.6, BS8110-1:1997.
9. Compare the design punching shear stress with the calculated punching shear resistance.
10. Evaluate the design by inspecting whether the design forces are smaller than the section resistance.
11. Review the arrangement of reinforcement if the slab section design is inadequate.