scholarly journals Repair of Fire-Damaged Reinforced Concrete Members with Axial Load: A Review

2019 ◽  
Vol 11 (4) ◽  
pp. 963 ◽  
Author(s):  
Jun Zhou ◽  
Lu Wang
Keyword(s):  
Reinforced Concrete ◽  
Residual Strength ◽  
Axial Load ◽  
Common Knowledge ◽  
Structural Safety ◽  
Experimental Investigations ◽  
Great Loss ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Structural Fires

It is common knowledge that structural fires have led to a great loss of buildings and damage to property in the past two decades. Therefore, there is a growing need to provide approaches for post-fire repair of structural members to enhance their structural safety. This paper presents a state-of-the-art review on the repair of fire-damaged reinforced concrete (RC) members with axial load. The investigations into the effects of loading method, physical dimension and bonding behavior on the residual strength of members are presented. In the meantime, the available experimental investigations on the performance of fire-damaged RC members with axial load repaired with concrete jacketing, steel jacketing and fiber-reinforced polymer (FRP) jacketing are summarized. Moreover, models for predicting the residual strength of fire- damaged columns are reviewed.

Minimum thickness of concrete members reinforced with fibre reinforced polymer bars

2001 ◽  
Vol 28 (4) ◽  
pp. 583-592 ◽  
Author(s):  
Amin Ghali ◽  
Tara Hall ◽  
William Bobey
Keyword(s):  
Reinforced Concrete ◽  
Minimum Thickness ◽  
Reinforced Polymers ◽  
Flexural Members ◽  
Steel Reinforced Concrete ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Steel Bars ◽  
Fibre Reinforced Polymer ◽  
Frp Bars

To avoid excessive deflection most design codes specify the ratio (l/h)s, the span to minimum thickness of concrete members without prestressing. Use of the values of (l/h)s specified by the codes, in selecting the thickness of members, usually yields satisfactory results when the members are reinforced with steel bars. Fibre reinforced polymer (FRP) bars have an elastic modulus lower than that of steel. As a result, the values of (l/h)s specified in codes for steel-reinforced concrete would lead to excessive deflection if adopted for FRP-reinforced concrete. In this paper, an equation is developed giving the ratio (l/h)f for use with FRP bars in terms of (l/h)s and (εs/εf), where εs and εf are the maximum strain allowed at service in steel and FRP bars, respectively. To control the width of cracks, ACI 318-99 specifies εs = 1200 × 10–6 for steel bars having a modulus of elasticity, Es, of 200 GPa and a yield strength, fy, of 400 MPa. At present, there is no value specified for εf; a value is recommended in this paper.Key words: concrete, cracking, deflection, fibre reinforced polymers, flexural members, minimum thickness.

scholarly journals FLEXURAL CAPACITY OF CONCRETE BEAMS REINFORCED WITH STEEL AND FIBRE‐REINFORCED POLYMER (FRP) BARS

2004 ◽  
Vol 10 (3) ◽  
pp. 209-215
Author(s):  
Hau Yan Leung
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Beam Design ◽  
Reinforced Concrete Member ◽  
Current Design ◽  
Fibre Reinforced Polymer ◽  
Steel Rebars ◽  
Frp Bars

Although much research on concrete beams reinforced with fibre‐reinforced polymer (FRP) rods has been conducted in recent years, their use still does not receive the attention it deserves from practicising engineers. This is attributed to the fact that FRP is brittle in nature and the collapse of FRP‐reinforced concrete member may be catastrophic. A rational beam design can incorporate a hybrid use of FRP rods and steel rods. Current design codes only deal with steel‐reinforced or FRP‐reinforced concrete members. Therefore in this study some design charts and equations for concrete beam sections reinforced with FRP rods and steel rebars were generated. Results from the theoretical derivations agreed well with experimental data.

scholarly journals OPTIMISATION OF THICKNESS OF FIBRE REINFORCED POLYMER SHEETS FOR STRENGTHENING REINFORCED CONCRETE BEAMS WITH FLEXURAL DEFICIENCY

2016 ◽  
Vol 36 (1) ◽  
pp. 45-49
Author(s):  
JM Kaura
Keyword(s):  
Reinforced Concrete ◽  
High Capacity ◽  
Cost Effective ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Reduced Gradient ◽  
Generalized Reduced Gradient

The use of Fiber Reinforced Polymer (FRP) is becoming a widely accepted solution for repairing and strengthening of deteriorated reinforced concrete members, to restore their load carrying capacities. One of the major concerns in the use of FRP is its cost. This therefore calls for the use of efficient and cost effective design approach. Design efficiency in terms of cost can be achieved through optimisation. In the present paper, Generalized Reduced Gradient (GRG) optimisation technique was employed to optimize the strengthening cost of a simply supported reinforced concrete beam strengthened with Fibre Reinforced Polymer (FRP). Optimum design charts for the considered problem were presented. The results showed that considerable savings in thickness can be achieved using FRP of high modulus of elasticity. For example at very high capacity reduction say 70% (kc = 0.3), the required FRP thicknesses for FRP with elastic moduli of 25GPa, 50GPa, 75GPa, 100GPa, 125GPa and 150GPa are respectively equal to 2.5mm, 1.75mm, 0.75mm, 0.6mm, 0.5mm and 0.4mm.  http://dx.doi.org/10.4314/njt.v36i1.7

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