1. ACI Fall 2016 Convention-Philadelphia
Deflection Task Group Progress Report
Long Term Deflection

2. Kiang Hwee Tan and Mithun Kumar Saha
Material Properties
Concrete
Compressive Strength (f`c) = 40 MPa
Modulus of Elasticity (Ec) = 27.2 GPa
Modulus of rupture (Er) = 4.67 MPa
Steel
Yield Strength (Fy) for T16, T10, and R6 = 525, 520, and 212 MPa
Modulus of Elasticity (Es) for T10, T6, and, R6 = 183,194, and 200 GPa
Fiber
Tensile strength = 1700 MPa
Modulus of Elasticity (E) = 71 GPa
Thickness = 0, 0.8 mm (one layer), and 2.4 mm (3 layers)

3. Kiang Hwee Tan and Mithun Kumar Saha
Resin
Tensile strength = 54 MPa
Modulus of Elasticity (Ef) = 3 GPa
Fiber Reinforced Polymer (FRP)
Modulus of Elasticity (Ef) = 39 GPa
Specimen Details
Cross section 100*125 mm, total length=2000 mm with reinforcement details shown below.
Loaded as simply supported over a 1800 mm as clear span.
Applied loads (Ps) = 15.8, 18.8, and 22.8 KN
Flexural capacity (Pu) of beams with 0 FRP= 26.8 KN
Flexural capacity (Pu) of beams with 0.64% FRP (0.8 mm, thickness) = 31.9 KN
Flexural capacity (Pu) of beams with 1.92% FRP (2.4 mm, thickness) = 38.6 KN
Long Term Deflection = 2 years

4. Kiang Hwee Tan and Mithun Kumar Saha
Deflections of FRP-Bonded RC Beams
Beam
Load
(KN)
Ps/ Pu
ratio
FRP ratio
(%)
Immediate
deflection (mm)
*Time-dependent deflection (mm)
Total deflection (mm)
Total deflection / Immediate
deflection 1
15.8
0.59
6.72
3.77
10.49
1.56 2
18.8
0.70
8.39
4.79
13.18
1.57 3
22.8
0.85
11.55
5.35
16.90
1.46
0.49
0.64
5.09
3.39
8.48
1.66
059
6.76
4.09
10.82
1.6
8.44
4.61
13.05
1.54
0.40
1.92
3.78
3.30
7.08
1.87
5.37
3.92
9.29
1.73
7.41
11.33
1.53
*Time-dependent deflection = Total deflection (at the end of 2 years) – Immediate deflection

5. M.M. Reda Taha, M. J. Masia, K. K. Choi, P. L. Shrive, and N. G.Shrive
Specimen Details
Cross section 280*180 mm, total length=3500 mm with reinforcement details shown below.
Loaded as simply supported over 3200 mm as a clear span.
Applied loads (Ps) = KN as two-point loads (four-point bending)
Compressive Strength of concrete (f`c) = 32 – 36.6 MPa
Four longitudinal bars, 11.3 mm dia with seven10M stirrups
Yield Strength (Fy) 414 MPa (Assumption)
Carbon Fiber Reinforced Polymer (CFRP )
Tensile strength = 2800 MPa
Modulus of Elasticity (E) = 165 GPa
Thickness = 1.2 mm
Long Term Deflection = 6-1/2 years

6. M.M. Reda Taha, M. J. Masia, K. K. Choi, P. L. Shrive, and N. G.Shrive
Flexural capacity (Pu) of beam with 0 FRP = KN
Flexural capacity (Pu) of beam with 1.2 mm thickness of FRP = KN
Beam
Load
(KN) Pu
Ps/ Pu
ratio
CFRP
Thickness
(mm)
Immediate
deflection (mm)
*Time-dependent deflection (mm)
Total deflection after 6.5 years (mm)
Total deflection / Immediate
deflection 1
10.34
22.31
0.463
0.0
10.01
6.6
16.61
1.66 2
51.24
0.20
1.2
3.76
4.52
8.28
2.20
*Time-dependent deflection = Total deflection (at the end of 2 years) – Immediate deflection

7. Recommendation
Use l = 2
Acquire deflections from actual load tests (promised by Gustavo and Tarek)