scholarly journals Experimental Study on Shear Strengthening of RC Beams with an FRP Grid-PCM Reinforcement Layer

2019 ◽  
Vol 9 (15) ◽  
pp. 2984 ◽  
Author(s):  
Rui Guo ◽  
Lianheng Cai ◽  
Shinichi Hino ◽  
Bo Wang
Keyword(s):  
Evaluation Method ◽  
Cement Mortar ◽  
Effective Strain ◽  
Shear Capacity ◽  
Fiber Reinforced Polymer ◽  
Strengthening Effect ◽  
Rc Beams ◽  
Shear Strengthening ◽  
Reinforced Polymer ◽  
Series Of Experiments

This paper investigates the shear strengthening effect of a number of reinforced concrete (RC) beams strengthened by a reinforcement layer which combines carbon fiber reinforced polymer (CFRP) grid and polymer cement mortar (PCM). A total of ten RC beams, including three types of specimens as Series A and seven kinds of specimens as Series B, were prepared and investigated. The test variables in both series of experiments included various reinforcement ranges and different reinforcement amounts that consisted of CFRP grids’ spacing and cross-section areas. The experimental results suggest that the shear strengthening effect of the CFRP grid-PCM layer for RC beams is obvious and adequate. Meanwhile, better performance is observed if the CFRP grid-PCM reinforcement layer is used for the full sectional reinforcement of RC beams with an I-shaped profile, in contrast to RC beams with reinforcement of the web only. In addition, a new evaluation method based on the effective strain of the CFRP grid is developed to determine the shear capacity of RC beams strengthened by a CFRP grid-PCM layer.

A proposed strengthening model considering interaction of concrete-stirrup-FRP system for RC beams shear-strengthened with EB-FRP sheets

2018 ◽  
Vol 37 (10) ◽  
pp. 685-700 ◽  
Author(s):  
Weiwen Li ◽  
Chengyue Hu ◽  
Zejie Pan ◽  
Wei Peng ◽  
Yong Yang ◽  
...  
Keyword(s):  
Effective Strain ◽  
Polymer System ◽  
Design Guidelines ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites ◽  
Externally Bonded

Many factors can affect the shear capacity of fiber-reinforced polymer in reinforced concrete beams shear-strengthened with externally bonded fiber-reinforced polymer composites. Undoubtedly, the interaction of concrete-stirrup-fiber-reinforced polymer system is one of the key factors. However, most of the existing fiber-reinforced polymer design guidelines do not take account of this important factor on predicting fiber-reinforced polymer shear capacity. This study provides an advanced strengthening model that comprehensively considers the interaction among concrete, stirrup, and fiber-reinforced polymer for calculating the fiber-reinforced polymer effective strain. The advanced strengthening model provides a more accurate prediction for the fiber-reinforced polymer shear contribution compared with existing design guidelines.

scholarly journals Shear Strengthening of RC Beams Using Sprayed Glass Fiber Reinforced Polymer

2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
Sayed Mohamad Soleimani ◽  
Nemkumar Banthia
Keyword(s):  
Carrying Capacity ◽  
Concrete Surface ◽  
Fiber Reinforced Polymer ◽  
Load Carrying Capacity ◽  
Rc Beams ◽  
Glass Fiber Reinforced Polymer ◽  
Shear Strengthening ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Load Carrying

The effectiveness of externally bonded sprayed glass fiber reinforced polymer (Sprayed GFRP) in shear strengthening of RC beams under quasi-static loading is investigated. Different techniques were utilized to enhance the bond between concrete and Sprayed GFRP, involving the use of through bolts and nuts paired with concrete surface preparation through sandblasting and through the use of a pneumatic chisel prior to Sprayed GFRP application. It was found that roughening the concrete surface using a pneumatic chisel and using through bolts and nuts were the most effective techniques. Also, Sprayed GFRP applied on 3 sides (U-shaped) was found to be more effective than 2-sided Sprayed GFRP in shear strengthening. Sprayed GFRP increased the shear load-carrying capacity and energy absorption capacities of RC beams. It was found that the load-carrying capacity of strengthened RC beams was related to an effective strain of applied Sprayed GFRP. This strain was related to Sprayed GFRP configuration and the technique used to enhance the concrete-FRP bond. Finally, an equation was proposed to calculate the contribution of Sprayed GFRP in the shear strength of an RC beam.

A Study on Effective Strains in Different FRP Shear Strengthening Schemes for Analytical Optimized Truss Models

2014 ◽  
Vol 935 ◽  
pp. 168-171
Author(s):  
Hor Yin ◽  
Wee Teo
Keyword(s):  
Effective Strain ◽  
Design Guidelines ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Shear Strengthening ◽  
Reinforced Polymer ◽  
Truss Model ◽  
Minimum Total Energy ◽  
Current Design ◽  
Optimized Model

This paper presents an optimized truss model based on the principle of minimum total energy theorem. Six most recent effective strain ɛfrp,e models including three design guidelines were selected for the analysis. Three reinforced concrete beams strengthened with different fiber reinforced polymer (FRP) schemes were chosen. Comparing with current design guidelines, the results of these three beams indicate that the optimized model is promising and encouraging.

Calculation of Shear Capacity of Steel and Concrete Composite Beams Strengthened with FRP

2012 ◽  
Vol 166-169 ◽  
pp. 3290-3293
Author(s):  
Jiong Feng Liang ◽  
Ze Ping Yang ◽  
Jian Bao Wang ◽  
Jian Ping Li
Keyword(s):  
Experimental Data ◽  
Composite Beams ◽  
Shear Capacity ◽  
Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Reinforced Polymer

Some calculated methods of shear capacity of RC beams strengthened with FRP (fiber reinforced polymer) are reviewed based on the experimental data on shear capacity of RC beams strengthened with FRP. Therefore, according to the destruction forms of steel and concrete composite beams strengthened with FRP, the formula for calculating the shear capacity of the beams are given. The formula is expressed clearly, simple and easy to use.

scholarly journals SHEAR CAPACITY PREDICTION FOR STIRRUP-CORRODED RC BEAMS STRENGTHENED WITH FRP

2019 ◽  
Vol 11 (1) ◽  
pp. 32-39 ◽  
Author(s):  
Ahmed K. El-Sayed
Keyword(s):  
Shear Capacity ◽  
Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Accelerated Corrosion ◽  
Rc Structures ◽  
Cfrp Sheets ◽  
Four Point Bending ◽  
Reinforced Polymer ◽  
Shear Reinforcements ◽  
Corrosion Of Steel

Corrosion of steel reinforcement represents one of the main causes of deterioration and degradation of reinforced concrete (RC) structures. Shear reinforcements (stirrups) as an outer reinforcement in RC beams are more susceptible to corrosion problems and damage. This paper describes an analytical procedure for predicting the shear capacity of stirrup-corroded RC beams strengthened in shear using FRP laminates. The procedure shows how to incorporate the effects of the damages due to corrosion of stirrups into the design equations. An experimental investigation has been conducted to provide experimental data on the shear capacity of RC beams with corrosion-damaged stirrups strengthened using carbon fiber reinforced polymer (CFRP) sheets. The experimental study comprised three beams of 200 mm wide, 350 mm deep, and 2800 mm long. The steel stirrups in the beams were corroded using an accelerated corrosion technique. After CFRP strengthening, the beams were tested in four-point bending under a simply supported span of 2400 mm. The shear capacity of the strengthened beams was predicted using the proposed procedure and compared with the experimental ones. Good correlations were found between the predicted and experimental shear strength of the beams.

scholarly journals Adhesion, strengthening and durability issues in the retrofitting of Reinforced Concrete (RC) beams using Carbon Fiber Reinforced Polymer (CFRP) – A Review

2019 ◽  
Vol 9 (2) ◽  
pp. 130-151
Author(s):  
Pedro J. Poot Cauich ◽  
Rodolfo Martínez-Molina ◽  
José Luis Gamboa Marrufo ◽  
Pedro Jesus Herrera Franco
Keyword(s):  
Thermal Environment ◽  
Fiber Reinforced Polymer ◽  
Strengthening Effect ◽  
Rc Beams ◽  
Reinforced Polymer ◽  
Cfrp Sheet ◽  
Key Factor ◽  
Cfrp Composite ◽  
Interface Bond

This paper addresses the mechanics of adhesion, strengthening effect and durability issues of applications of CFRP composite materials in beams. The application of CFRP materials has been widely described, but the main focus has been on overall failure parameters. The first issue is strengthening capability of CFRP reinforcement for concrete beams. The second is the local interface bond stress-slip relationship, that is, the local t-slip. The last issue is the durability of the CFRP sheet/plate, when exposed to a hydro-thermal environment. The role of adhesion and the mechanics of concrete-CFRP adhesion and a sound understanding of the interface between the CFRP and concrete behavior is the key factor for controlling debonding failures in CFRP-strengthened RC beams.

Experimental Study on Shear Capacity of RC Beams Strengthened with Carbon Fiber Reinforced Polymer Mandated by ACli 440

2016 ◽  
Vol 845 ◽  
pp. 154-157
Author(s):  
Sri Tudjono ◽  
Himawan Indarto ◽  
Monica Devi
Keyword(s):  
Experimental Study ◽  
Carbon Fiber ◽  
Shear Capacity ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Rc Beam ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

Shear reinforcement for retrofitting an RC beam using unidirectional Carbon Fiber Reinforced Polymer (CFRP) woven can only be applied on the beam’s body below the concrete floor slab. Thus, it cannot fully curb like the way stirrups do, in which it will affect the shear capacity. The CFRP can only be ‘n’or ‘u’ shaped, taking into consideration the direction of shear force. Herein, the experimental study of the shear capacity ofshear capacity the beam strengthened by FRP is carried out.shear capacity The beams are RC beams of width 150 mm, height 300 mm, span of 1000 mm, f'c = 26 MPa having 2 bar of 19 mm diameter (fy = 403.65 MPa) and stirrups 6 mm diameter of 250 mm spacing (fy=375 MPa). The shear capacity measured is then compared with the shear capacity calculated using ACI 440. The result shows that the shear capacity measured from experiment is greater than the shear capacity calculated by ACI 440. Also, theshear capacity of RC beam with CFRP reinforcement n shape is greater than u shape.

Shear Capacity of RC Beams with Web Openings Strengthened with Multi Layers of CFRP

2014 ◽  
Vol 567 ◽  
pp. 494-498 ◽  
Author(s):  
Bashar S. Mohammed ◽  
Omar Alanni
Keyword(s):  
Reduction Factor ◽  
Shear Capacity ◽  
Fiber Reinforced Polymer ◽  
Rc Beam ◽  
Rc Beams ◽  
Web Openings ◽  
Web Opening ◽  
Reinforced Polymer ◽  
Eurocode 2 ◽  
Load Carrying

In some cases a cut-out web opening in a reinforced concrete (RC) beam is required to facilitate the passage of electrical and mechanical pipes and ducting from one side to another. The presence of cut-out web openings will lead to decreasing in the load carrying capacity of these RC beams. Therefore, strengthening the vicinity of these openings by using Carbon Fiber Reinforced Polymer (CFRP) will represent the best practical solution. In this study, thirteen RC beams with different sizes of cut-out web openings and with different layers of CFRP strengthening and also one solid RC beam (control) were prepared and tested to failure. The outcome of this experimental and analytical study showed that the modified Eurocode 2 model can reasonably be used in computing the shear forces of RC beams having the vicinity of their cut-out web openings strengthened with single/multi layers of CFRP. In addition, for safe design purposes, a reduction factor has been suggested as well.

Sign in / Sign up

Export Citation Format

Share Document