The document discusses using carbon fiber reinforced polymer (CFRP) to strengthen concrete beams experiencing shear cracks. A concrete beam supporting a 200 MT load at each support was originally designed incorrectly as a slender beam rather than a deep beam. Analysis showed the beam was overstressed, exhibiting typical shear cracks. CFRP strengthening was proposed to reinforce the beam without requiring a plant shutdown during repairs. CFRP would be applied to increase the beam's shear capacity and allow it to support the required loads.

1. CFRP Strengthening of Concrete Beam Shear Cracks
Ir. Alex E. Kajuputra, MSc
Senior Structural Consultant
1Info; +60-19-397 5580 (Hp/WA)
CFRP Strengthening of Concrete Beam Shear Cracks
Ir. Alex E. Kajuputra, MSc
Senior Structural Consultant

2. CFRP Strengthening of Concrete Beam Shear Cracks
Ir. Alex E. Kajuputra, MSc
Senior Structural Consultant
2Info; +60-19-397 5580 (Hp/WA)
CONCRETE BEAM SHEAR CRACKS
Concrete Beams
Shear Cracks
200 MT LOAD at each
Support Pedestal
Objective
- Fit-For-Purpose Analysis
- Structural Repair
- Structural Strengthening
Criticality
- Load 200 MT from each
support pedestal
- Primary concrete Beam
failure propagates global
structural failure
- Plant Shutdown
- Toxic gas and liquid release
Temporary
Support

3. CFRP Strengthening of Concrete Beam Shear Cracks
Ir. Alex E. Kajuputra, MSc
Senior Structural Consultant
3Info; +60-19-397 5580 (Hp/WA)
Fit-For-Purpose Analysis
Codes, Standard and Specifications
- ACI 318 – 02 American Concrete Institute
Analysis Findings
- The concrete beam 800x1400 mm span 7200 mm is concluded as ‘Deep
Beam’ in accordance to ACI 318-02 Appendix A
- The concrete beam were originally analyzed with conventional beam
theory as ‘Slender Beam’ instead of ‘Deep Beam’
- Deep beam shall be designed using either Nonlinear Analysis or Strut &
Tie Model in accordance to ACI 318-02 Section 11.8
- Strut & Tie Model analysis indicates that the beam is overstressed with
maximum UC of 1.19 (Max allowed is 1.0).
- The cracks pattern found are typical type for shear cracks, which are
dominant forces in deep beam.
Mitigation
- Crack injection with epoxy based material to regain the friction
strength of the concrete beam
- To Install temporary support while waiting for permanent repair
and strengthening.
- Carbon Fiber Reinforced Polymer (CFRP) strengthening for clean,
fast, easy and do not require shut down during execution.

4. CFRP Strengthening of Concrete Beam Shear Cracks
Ir. Alex E. Kajuputra, MSc
Senior Structural Consultant
4Info; +60-19-397 5580 (Hp/WA)
Definition of Deep Beam
(As referred to ACI 318-02 Appendix A – American Concrete Institute)

5. CFRP Strengthening of Concrete Beam Shear Cracks
Ir. Alex E. Kajuputra, MSc
Senior Structural Consultant
5Info; +60-19-397 5580 (Hp/WA)
Strut-and-Tie Model
(As referred to ACI 318-02 Appendix A – American Concrete Institute)

6. CFRP Strengthening of Concrete Beam Shear Cracks
Ir. Alex E. Kajuputra, MSc
Senior Structural Consultant
6Info; +60-19-397 5580 (Hp/WA)
Carbon Fiber Reinforced Polymer (CFRP)
Shear Strengthening

7. CFRP Strengthening of Concrete Beam Shear Cracks
Ir. Alex E. Kajuputra, MSc
Senior Structural Consultant
7Info; +60-19-397 5580 (Hp/WA)

8. CFRP Strengthening of Concrete Beam Shear Cracks
Ir. Alex E. Kajuputra, MSc
Senior Structural Consultant
8Info; +60-19-397 5580 (Hp/WA)
Carbon Fiber Reinforced Polymer (CFRP)
Shear Strengthening

9. CFRP Strengthening of Concrete Beam Shear Cracks
Ir. Alex E. Kajuputra, MSc
Senior Structural Consultant
9Info; +60-19-397 5580 (Hp/WA)
alex.kajuputra@gmail.com
Hp/WA: +60-19-397 5580
THE END