scholarly journals CONCRETE SLAB REINFORCED WITH GFRP AND EXTERNALY STRENGTH WITH CARBON SHEET UNDER IMPACT LOAD

2021 ◽  
Vol 25 (Special) ◽  
pp. 4-1-4-12
Author(s):  
Eman H. Hamza ◽  
◽  
Mutaz K. Madlum ◽  
Keyword(s):  
Dynamic Behavior ◽  
Impact Load ◽  
Concrete Slab ◽  
Shear Capacity ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Cfrp Sheet ◽  
Carbon Sheet ◽  
Rc Slabs ◽  
The Cost

When FRP bars used in concrete structures that exposed to harsh environments, their service life extended and the cost of their life cycle reduced. Recently, methods of externally bonding Carbon Fiber Reinforced Polymer (CFRP) sheets to RC slabs proposed to improve the dynamic behavior of RC slabs under impact load. In this study, the effect of the number of CFRP sheet layers (one or two) and the arrangement of CFRP sheets (covering the whole or parts of the surface) on the dynamic behavior of slabs reinforced with GFRP bar investigated. Nine specimens of (1550×1550×150) mm reinforced by GFRP bars were tested. A single control specimen was unstrings and eight specimens were strength with CFRP sheet on the tension face. A rigid steel projectile used to apply two dropping-weights of 150 kg as an impact load. The height of the drop was 5 meters. To determine punching shear capacity and critical velocity of perforation, different codes used and compared with the experimental results. The results of the experiments revealed that slab shear properties have a significant impact on their general behavior. Strength slab with carbon sheet enhances the behavior of RC slabs under impact loads and increases shear punching capacity.

scholarly journals EFFECT OF IMPACT LOAD ON THE PERFORMANCE OF CONCRETE SLABS REINFORCED BY CFRP BARS

2021 ◽  
Vol 25 (01) ◽  
pp. 68-79
Author(s):  
Hind T. Khamies ◽  
◽  
Mu’taz K. Medhlom ◽  
Keyword(s):  
Impact Load ◽  
High Strength ◽  
Shear Capacity ◽  
Experimental Results ◽  
Slab Thickness ◽  
Empirical Formulas ◽  
Steel Bars ◽  
Rc Slabs ◽  
The Cost ◽  
Frp Bars

Using FRP bars in the concrete structures under harsh environment produces extension of those service life and dropping of the cost of their lifecycle. This study investigated the influence of slab thickness, material of rebar, arrangement of reinforcement and mass’s dropped on the dynamic behavior of RC slabs by using laboratory experiments. Seven specimens 1550×1550 mm dimension with two thickness 120 and 150mm, single control specimen reinforced with steel bars and six specimens reinforced by CFRP bars were experimentally investigated under sequential dropping-weight ranged from 50 to 150kg, it was a rigid steel projectile, used to apply impacting load. 2.5m was the height of dropping. For estimated penetration depth, three empirical formulas have been used, ACE formulae was preferable predictor than other formulas. Different codes were used to calculation punching shear capacity and critical velocity of perforation and compared the experimental results with these codes. The experimental results showed that the shear properties of slabs have a significant effect in their general behavior. And preferable performance in FRP slabs than slabs reinforced with steel can be achieved which considering high strength and corrosion resistance of this material, which makes it a suitable choice for reinforcing materials.

scholarly journals Performance of Reinforced Concrete Slab with Opening Strengthened Using CFRP

Fibers ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 25
Author(s):  
Syafiqah Shahrul Aman ◽  
Bashar S. Mohammed ◽  
Mubarak Abdul Wahab ◽  
Abdullah Anwar
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Fiber Reinforced Polymer ◽  
Sufficient Information ◽  
Reinforced Concrete Slab ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Cfrp Sheet ◽  
And Performance ◽  
Rc Slabs

Openings in reinforced concrete (RC) slabs are not commonly prescribed in design codes. Even when they are, they raise concerns regards to the size of the openings and the location of the applied loads. Lack of sufficient information about the load-carrying capacity of the slabs with openings and performance is another concern. Hence, this research addresses the structural behavior of slabs with openings coated with Carbon Fiber Reinforced Polymer (CFRP) sheet. In the experimental part, ten slabs were cast with a dimension of 1000 mm × 530 mm × 25 mm, among which nine slabs had openings and one slab was without opening (control slab). The configuration of the CFRP sheet includes coating in the form of single, double, and triple layers. Experimental results show that the slab with a triple coating of the CFRP layer offers the maximum resistance towards the loading rate. Moreover, with the increase in CFRP layers, the value of deflection is minimized.

An Study on the Flexural Performance of Reninforced Concrete Beams Considering Loading History with Pre-Stressed Cfrp Sheets

2011 ◽  
Vol 105-107 ◽  
pp. 853-856
Author(s):  
Zhe Li ◽  
Gang Li ◽  
Qin Zhao ◽  
Shuai Zhang
Keyword(s):  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Impact Factors ◽  
Cfrp Sheets ◽  
Flexural Performance ◽  
Reinforced Polymer ◽  
Secondary Load ◽  
Cfrp Sheet

For the effect of nonpre-stressed carbon fiber reinforced polymer (CFRP) Sheet Strengthening concrete beams to improve bending stiffness and crack resistance is not satisfactory, and it is difficult to totally unloading on the actual reinforcement, so in this paper, ANSYS is used to research the strengthened effectiveness and impact factors of pre-stressed CFRP reinforced concrete beams considering the secondary load.

scholarly journals Punching Strengthening of Concrete Slab-column Connections Using Near Surface Mounted (NSM) Carbon Fiber Reinforced Polymer (CFRP) Bars

2020 ◽  
pp. 1-14
Author(s):  
Ahmed H. Abdel-Kareem
Keyword(s):  
Carbon Fiber ◽  
Concrete Slab ◽  
Tensile Force ◽  
Shear Capacity ◽  
Punching Shear ◽  
Near Surface ◽  
Reinforced Polymer ◽  
Externally Bonded ◽  
Near Surface Mounted ◽  
Strengthening Technique

This paper investigates experimentally the effect of near surface mounted (NSM) carbon fiber reinforcement polymer (CFRP) bars as externally strengthening on the punching shear behavior of interior slab-column connections. Many researchers used NSM as a novel strengthening technique in various structural elements. However, the strengthening of slab-column connections using NSN is relatively new. Seven Reinforced concrete (RC) square slabs with a concentric column were tested over simply supported four sides. One control specimen was tested without strengthening, four specimens were strengthened using NSM-CFRP bar installed in pre-cut groove surrounded the column at the tension side of the slab, and two specimens were strengthened using externally bonded (EB) CFRP strips which have the same tensile force of the CFRP bars. The arrangement and the location of the strengthened materials were also test variables. The test results showed that using NSM strengthening technique significantly increased the punching shear capacity and ultimate stiffness compared to using EB strengthening technique. Where the increasing in the punching capacity and ultimate stiffness were 18% and 13-18%, respectively. Moreover, the NSM-CFRP bars greatly reduced the cracks in the punching shear zone around the columns. The measured ultimate punching shear capacity for the tested specimens showed very reasonable agreement with the calculated punching loads based on an analytical model for slab-column connections strengthened using FRP that account for its arrangement and location.  

scholarly journals Shear capacity of reinforced concrete beams strengthened with web side bonded CFRP sheets

2019 ◽  
Vol 258 ◽  
pp. 04010
Author(s):  
Rendy Thamrin ◽  
Zaidir ◽  
Sabril Haris
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Concrete Cover ◽  
Shear Capacity ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Longitudinal Reinforcement ◽  
Flexural Mode ◽  
Cfrp Sheets ◽  
Reinforced Polymer

The shear capacity of reinforced concrete beams strengthened with web side bonded carbon fiber-reinforced polymer (CFRP) sheets was measured experimentally. Nine reinforced concrete beams without stirrups; three control beams and six beams strengthened with minimal application of web side bonded CFRP sheets, were tested. The test variables were ratio of longitudinal reinforcement (1%, 1.4%, and 2.4%) and angle of application of CFRP sheets (450 and 900). The test results show that reinforced concrete beams strengthened with web side bonded CFRP sheets have higher shear capacity compared to the control beams. Shear capacity of strengthened beams with 450 angle of application of CFRP sheets is similar to that of beams strengthened with 900 angles. Beams with 1% of longitudinal reinforcement ratio failed in flexural mode indicated by concrete crushing in compression zone while beams with higher longitudinal reinforcement ratio (1.4% and 2.4%) failed in brittle mode as indicated by delamination of the concrete cover.

Experimental Research and Principle on Strengthened T-Beam with External Pre-Stressed Variable Section CFRP Sheets Based on Moment

2014 ◽  
Vol 1030-1032 ◽  
pp. 774-780
Author(s):  
Xiao Ying Chen ◽  
Jing Zhuo ◽  
Tang Ning Li
Keyword(s):  
Multiple Point ◽  
Test Results ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Strength Capacity ◽  
Cfrp Sheet ◽  
T Beam ◽  
Two Sides ◽  
Frp Sheet ◽  
Strengthening Method

An innovative external pre-stressed strengthening method, in which FRP (fiber reinforced polymer) sheet is placed outside of the concrete section and anchored in multiple-point, is based on moment of beam to change the area of section of FRP sheet along the length of beam. This strengthening method is that two ends of FRP sheet are first anchored by tightening WSGA (Wave-shaped-gear-anchor), then the FRP sheet is tensioned by tightening WSGG (Wave-shaped-gear-grip) on the middle of FRP sheet and accordingly pre-stressing force is built in FRP sheet. Two same 7m long reinforced concrete T-beams are strengthened at two sides of the beam with above strengthen technique, another same beam is strengthened with sticking CFRP sheet strengthen technique. Test results of strengthen beams indicate that this innovative external pre-stressed CFRP sheets strengthen technique could significantly improve the cracking load, yield load, ultimate load and stiffness of RC beams. The width of flexural cracks in concrete beams is effectively controlled and the strength capacity of the CFRP sheets is exploited.

Experimental Study on Bond Behavior between CFRP Sheet and Wood

2011 ◽  
Vol 368-373 ◽  
pp. 2314-2318
Author(s):  
Qi Fang Xie ◽  
Jian Yang Xue ◽  
Hong Tie Zhao ◽  
Jun Fang Hu
Keyword(s):  
Experimental Study ◽  
Bond Length ◽  
Strain Distribution ◽  
Fiber Reinforced Polymer ◽  
Engineering Practice ◽  
Bond Behavior ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Cfrp Sheet ◽  
Edge Location

Fiber-reinforced polymer (FRP) has been applied to reinforce wood structure with its many advantages. But results of experimental study and engineering practice have showed that the failure is generally caused for lack of bong strength between FRP and wood, so the bond behavior between FRP and wood is very important. In this paper, based on the shear bond experiment between wood and CFRP sheet, the bond properties are researched such as failure character, characteristic of strain distribution, effective bond length and bond strength. Results showed that: at the loaded-end, the strain of the CFRP sheets is the maximum, and then strains decrease quickly with the increase in distance from the loaded-end. Strain distribution along cross direction is not uniform and the strains of the center location are bigger obviously than that of the edge location. The effective bond length between CFRP sheet and wood is more than 120mm.

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 BEHAVIOR OF HIGH-STRENGTH CONCRETE CYLINDERS REPAIRED WITH CFRP SHEETS

2015 ◽  
Vol 22 (1) ◽  
pp. 56-64 ◽  
Author(s):  
Mohammad PANJEHPOUR ◽  
Nima FARZADNIA ◽  
Ramazan DEMIRBOGA ◽  
Abang Abdullah Abang ALI
Keyword(s):  
High Strength Concrete ◽  
Empirical Relationship ◽  
High Strength ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Strength Concrete ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Concrete Cylinders ◽  
Cfrp Sheet

This study aims to investigate the behavior of damaged high-strength concrete cylinders repaired using carbon fiber reinforced polymer (CFRP) sheet. The experimental work on CFRP-wrapped concrete cylinders with various predamage levels indicated that CFRP can precisely resist the axial aggravated deformation of cylinders caused by damaging under uniaxial loading. The findings also revealed that the energy absorption of the damaged specimens confined with CFRP was restored approximately three times more than that of the undamaged specimens without confinement. Therefore, an empirical relationship exists between the pre-damage levels and the uniaxial compressive strength reduction of the concrete cylinders.

scholarly journals Analysis of Strengths of Reinforced Concrete Beam Structures with CFRP Sheet Using Abaqus Software 6.14

2019 ◽  
Vol 21 (1) ◽  
pp. 9-19
Author(s):  
Ahmad Yasir ◽  
Mahmud Kori Effendi ◽  
Arie Taveriyanto ◽  
Henry Apriyatno
Keyword(s):  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Fiber Reinforced Polymer ◽  
Test Beam ◽  
Reinforcement Structure ◽  
Modeling And Analysis ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Cfrp Sheet ◽  
Abaqus Software

Abstract. Concrete beams are parts of a structure that serves as a channeling moment to the column structure. The structure of the beam which has undergone yielding reinforcement must be repaired. One of the beam repairs that can be done is by providing reinforcement using Carbon Fiber Reinforced Polymer (CFRP) sheets. The reinforcement structure modeling and analysis were carried out using the Abaqus software. There are two types of modeling, those were laboratory test beam modeled with Abaqus (BPA) and reinforced beam using CFRP (BPC). The beam structure analysis using Abaqus software showed that BPA beam experiences a first crack when the load is 5311.96 lbs with a 0.08 inch displacement, while the BPC-2 beam is first cracked at a load of 5019.93 lbs with a 0.10 inch displacement. The BPA beam experiences an ultimate when the load was 12620.84 lbs with a 0.64-inch displacement, while the BPC-2 beam experiences ultimate when the load was 12403.48 lbs with a displacement of 0.60 inch. The type of crack pattern in both beam models is the type of bending crack.

Sign in / Sign up

Export Citation Format

Share Document