10.01.03.049-One Way Slab

1. Slab Design - One Way CE- 416 Pre-stressed Concrete Lab Sessional Presented By : Md. Abu Raihan Id No:10.01.03.049 Course teachers: Munshi Galib Muktadir Sabreena Nasrin Department Of Civil Engineering Ahsanullah University of Science & Technology 1 11/25/2013

2. Definition Of Slab Definition Of One-Way Slab Deflection Design Concept Minimum Thickness Of One-Way Slab Load Assigned To Slabs Temperature And Shrinkage Reinforcement Temperature And Shrinkage Reinforcement Ratio Design Procedure Presentation Outline 2 11/25/2013

3. Layer of reinforce-concrete with uniform/variable thickness supported by restraints Figure: Definition Of Slab 3 11/25/2013

4. The ratio of the longer to the shorter side (L/B) of the slab is at least equal to 2.0 Support conditions is an important impact . Deflection is another important factor Load is distributed to the direction perpendicular of the supporting restraints. 4 Definition Of One Way Slab 11/25/2013

5. Picture Of One Way Slab

6. 6 Picture Of One Way Slab 11/25/2013

7. 7 Picture Of One Way Slab 11/25/2013

8. 8 Deflection 11/25/2013

9. 9 Deflection 11/25/2013

10. For the purpose of analysis and design, a unit strip of a slab is cut out at right to the supported beams. The method here is used for rectangular beams . Figure 10 Design Concept 11/25/2013

11. To control deflection , ACI Code 9.5.2.1 specifies minimum thickness values for one-way solid slabs, shown in Table. 11 Minimum Thickness Of Slab Element Simply Supported One-End Continuous Both-End Continuous Cantilever One-way Slab L/20 L/24 L/28 L/10 L is the span length direction of bending. If Wc ≈ 90 – 120 psf factor will be applied by ( 1.65-0.005Wc) If Fy ≠ 60 ksi factor will be ( 0.4 + Fy/100000) 11/25/2013

12. 12 Load Assigned Of Slab 11/25/2013

13. 13 Load Assigned Of Slab 11/25/2013

14. 14 Load Assigned Of Slab

15. Concrete gets shrinks and results cracking Cracks known as Hairline cracks. provide special reinforcement for shrinkage and temperature contraction in the direction perpendicular to the main reinforcement . Maximum lateral spacing 5h or 8″ 15 Temperature and Shrinkage reinforcement 11/25/2013

16. Based on the Gross Concrete Area Slabs with 40 or 50 grade reinforcement-0.002 Slabs with 60 grade reinforcement-0.0018 Slabs where reinforcement with yield stress exceeding 60 KSI at 35% yield-(0.0018*60000)/Fy 16 Temperature and Shrinkage reinforcement Ratio 11/25/2013

17. Step-1: From given panel find out the T min. Step-2: Find out the Factored Load.(Wu = 1.2*DL + 1.6*LL) Step-3: Find out Moments of the panel. (M = Moment Coefficients*Wu*L²) Step-4: Find out maximum steel ratio ( ρ max = 0.85* β 1 *( f´c / fy )*( ε u / ε u + 0.004) Step-5: Find d req . ( ) Step-6: As and a. ( ) Step-7: Temperature and shrinkage reinforcement Step-7: Reinforcement Detailing. 17 Design Procedure 11/25/2013

18. 18 Reinforcement Detailing

19. 19 Reinforcement Detailing 11/18/2013

20. 20 Thank You 11/25/2013