1- Minimum 1 inch spacing between bars in beams according to ACI code.

2- Curtailment at ends in case of simply supported beams L/8 from the face of support.

3- For continuous beams curtailment at L/3.

4- Maximum spacing for stirrups is 12 inch.

5- If reinforcement is provided in two layers then the 1-inch distance between bar layers must be maintained using spacer bars.

6- If effective depth of the beam is more than 36 inch than provide skin reinforcement up to d/2 maximum Ast/2. Use at least #6 bars.

7- For simple houses, 15ft or 20ft span beams can be supported on walls. Support beams by columns where the span is more.

8- Small foundation sizes i.e. 10ft or 12ft take them as hinge support.

9- Take raft foundations as fixed support.

10- Wall is idealized as a hinge.

11- Beam supported on girder idealized as a roller. Tip of the beam is fixed or glued to hinge while roller will move a little bit.

12- To avoid movement of negative structure assume one support as a hinge and other as rollers.

13- Negative reinforcement would be more at central support and positive reinforcement would be more for end spans.

14- Total moment i.e. sums of the positive and negative moment would always be wl2/8 between two supports.

15- Minimum thickness for footing should be 12 inches. Lean concrete up to 3 inches. This will do levelling.

16- Monolithic means continuity of negative reinforcement i.e. effect of one span is transferred to another span. The structure would become monolithic if you provide negative reinforcement. It would resist cracks otherwise it would become hinge support.

17- Footing is designed only for axial loads, no need to consider moments.

18- Beam-column joint is a rigid joint, not a fixed one.

19- In Pakistan, we either provide stiff beams or no beams at all. Beams have thickened the part of the slab and are pseudo supports, not true supports.

20- Provide negative reinforcement equal to positive reinforcement of one-way slab at the joint between one way and two-way slabs.

21- It is routine practice to provide a spacing multiple of each other.

22- Average load on slabs is between 200 to 300 psf.

23- Average positive moment on beams is between 1000 to 2000 kips-inch.

24- If the beam dimension is less than column then moment may arise if you have not placed them concentrically on the column. So same dimensions of beams and columns should be provided to flush them at the joint and pass steel of beam from the inner side of the column core.

25- 3000 psi is the compressive strength of concrete. The flexural capacity of concrete would be 7.5 sqrt (FC). Modulus of Elasticity for concrete would be 57000 sqrt (FC) / 1000.

26- In SAP, use centerline length of frame elements.

27- Usual column sizes are 12 x 12 square inches,18 x18 square inches etc.

Share this