Reinforcement of concrete using Glass Fiber Reinforced Polymer

The use of composite materials such as fiber reinforced polymers in strengthening and repairing of structural elements, particularly those made of reinforced concrete, is widely spreading. Among the fiber reinforced polymers (FRP) used for concrete strengthening, GFRP because they are more ductile and cheaper than carbon fibers and can be considered as an alternative solution to repair and strengthen concrete elements. The GFRP enhance significantly the ductility and strength of concrete by forming perfect adhesive bond between the wrapping material and concrete. Present study mainly emphasizes on effectiveness of external GFRP strengthening for concrete beams and columns. Total five circular concrete columns of 320 mm in height and 160 mm in diameter, and 30 concrete rectangular beams with a section of 40 mmx40 mm and 160 mm in length. Two columns were control and the rest three columns were strengthened with three types of GFRP. For beams, fifteen of them was control and the others were strengthened by GFRP with U-shape. All the test specimens were loaded to fail in axial compression and strain for columns, and under three-point bending for beams. The test results clearly demonstrated that compared with the ordinary concrete, the axial load carrying capacity and flexural strength increase for the reinforced concrete no matter the kind of the GFRP used even if it was in different storage condition

Reinforcement of concrete using Glass Fiber Reinforced Polymer

The use of composite materials such as fiber reinforced polymers in strengthening and repairing of structural elements, particularly those made of reinforced concrete, is widely spreading. Among the fiber reinforced polymers (FRP) used for concrete strengthening, GFRP because they are more ductile and cheaper than carbon fibers and can be considered as an alternative solution to repair and strengthen concrete elements. The GFRP enhance significantly the ductility and strength of concrete by forming perfect adhesive bond between the wrapping material and concrete. Present study mainly emphasizes on effectiveness of external GFRP strengthening for concrete beams and columns. Total five circular concrete columns of 320 mm in height and 160 mm in diameter, and 30 concrete rectangular beams with a section of 40 mmx40 mm and 160 mm in length. Two columns were control and the rest three columns were strengthened with three types of GFRP. For beams, fifteen of them was control and the others were strengthened by GFRP with U-shape. All the test specimens were loaded to fail in axial compression and strain for columns, and under three-point bending for beams. The test results clearly demonstrated that compared with the ordinary concrete, the axial load carrying capacity and flexural strength increase for the reinforced concrete no matter the kind of the GFRP used even if it was in different storage condition

PVC failure modelling through experimental and digital image correlation measurements

This paper analyses industrial PVC sheets structural integrity assessment widely used for different ranges of industrial applications. We investigated combined approaches focused on fracture toughness assessment to predict PVC mechanical behavior against failure. We ran a series of tests on tensile and single-edge notched samples at various crosshead speeds on a tensile test machine. PVC sheets' stress intensity factors were evaluated using both theoretical and experimental approaches to model crack growth. In the experimental procedure, we used the digital image correlation (DIC) method. We also developed a semi-empirical model to predict crack length over time. Furthermore, we proposed that the crack growth rate and stress intensity factor were satisfactorily correlated at all crosshead speeds and that the crack growth rate could be represented using a power-law model. In pre-cracked PVC specimens, the results showed that crack growth appears to be influenced by crosshead speed

Improvement of crack tip position estimation in DIC images by image processing methods

The study presents and compares an application of two procedures to identify the crack tip location in PVC Sent samples under a uniaxial tensile test based on the image processing method. An IDS camera captures several photos of the PVC surface as part of the image analysis procedure. All relevant data on crack initiation and propagation is collected and assessed using ImageJ software using image processing methods for detecting cracks. However, the second procedure involves a developed algorithm detecting the discontinuity using digital image correlation (DIC) measurement. Although, because of the experimental conditions, the acquisition of images by the digital camera is never perfect. This noise comes from several sources, including the digital camera, image distortion due to lens magnification or lens angle, the shape and size of the pattern, and electronic noise; ... This article discusses image enhancement methods to overcome these objectionable characteristics using and comparing several filters:  Gaussian, median, and Unsharp Mask filters. The performance of the Gaussian filter is better than the Median and Unsharp mask filters. This research demonstrates that DIC is an effective technique for monitoring deformation and understanding the failure mechanism with the best-suited filter

Influence of bonded length of the Carbon Fiber Reinforced Polymer Plates on the behavior of a concrete beam

Sometimes Aged or Damaged Structures need to be reinforced and retrofitted to enhance their performances and structural life, for this reason, the rehabilitation has been the subject of extensive research. The strengthening Reinforced Concrete structures is one of the most difficult and important tasks of civil engineering. Among the ways used to strength the concrete; the reinforcement using Carbon fiber reinforced polymer. This material has proved to be more efficient than other composites because of its high elastics modulus, its durability and this kind of materials are less affected by corrosive environmental conditions. The technique used in this study will be the external bonding of Carbon fiber reinforced polymer (CFRP) to a concrete beam. In this paper, the focus will be on the influence of bonded length of the CFRP Plates on the global behavior of the beam. The study is developed by the finite element program ABAQUS and will contain 11 specimens with a dimension of 100*200*1000mm and the length of the CFRP will be 100 mm, 200 mm, 300 mm, 400 mm, 500 mm, 600 mm, 700 mm, 800 mm, 900 mm, and a fully reinforced beam. Numerical results are presented and discussed herein

Improvement of crack tip position estimation in DIC images by image processing methods

The study proposes and compares two procedures to identify the crack tip location in PVC Sent samples under a uniaxial tensile test based on the image processing method

Seismic Retrofitting: Reinforced Concrete (RC) shear wall versus Reinforcement of RC element by Carbon Fiber Reinforced Polymer (CFRP) using PUSHOVER analysis

Seismic retrofitting of constructions vulnerable to earthquakes is a current problem of great political and social relevance. During the last sixty years, moderate to severe earthquakes have occurred in Morocco (specifically in Agadir 1960 and Hoceima 2004). Such events have clearly shown the vulnerability of the building stock in particular and of the built environment in general. Hence, it is very much essential to retrofit the vulnerable building to cope up for the next damaging earthquake. In this paper, the focus will be on a comparative study between two techniques of seismic retrofitting, the first one is a reinforcement using carbon fiber reinforced polymer (CFRP) applied to RC elements by bonding , and the second one is a reinforcement with a shear wall. For this study, we will use a non-linear static analysis -also known as Pushover analysis - on a reinforced concrete structure consisting of beams and columns, and composed from eight storey with a gross area of 240 m², designed conforming to the Moroccan Seismic code[1]

Seismic Retrofitting: Reinforced Concrete (RC) shear wall versus Reinforcement of RC element by Carbon Fiber Reinforced Polymer (CFRP) using PUSHOVER analysis

Seismic retrofitting of constructions vulnerable to earthquakes is a current problem of great political and social relevance. During the last sixty years, moderate to severe earthquakes have occurred in Morocco (specifically in Agadir 1960 and Hoceima 2004). Such events have clearly shown the vulnerability of the building stock in particular and of the built environment in general. Hence, it is very much essential to retrofit the vulnerable building to cope up for the next damaging earthquake. In this paper, the focus will be on a comparative study between two techniques of seismic retrofitting, the first one is a reinforcement using carbon fiber reinforced polymer (CFRP) applied to RC elements by bonding , and the second one is a reinforcement with a shear wall. For this study, we will use a non-linear static analysis -also known as Pushover analysis - on a reinforced concrete structure consisting of beams and columns, and composed from eight storey with a gross area of 240 m², designed conforming to the Moroccan Seismic code[1]