scholarly journals Shear-bond behavior of fiber reinforced polymer (FRP) rods and sheets

2018 ◽  
Vol 195 ◽  
pp. 02001
Author(s):  
Aylie Han ◽  
Buntara S. Gan ◽  
Agung Budipriyanto
Keyword(s):  
Epoxy Resin ◽  
Concrete Surface ◽  
Failure Behavior ◽  
Direct Function ◽  
Moment Capacity ◽  
Bond Behavior ◽  
Reinforced Polymer ◽  
Application Procedure ◽  
External Reinforcement ◽  
Direct Tensile

The use of external reinforcement has gained an increasingly major position due to the adjustment in earthquake standards, mandating a significant improvement in the section’s moment capacity. Studies on the behavior and enhancement contributed by FRP sheets demonstrated that its effectiveness was a direct function of the shear-bond strength. A prominent contributing factor was the response of the interface between the sheets and the epoxy resin, and the interface between the epoxy resin to the concrete surface. Recently, FRP rods were produced. These rods which are 8 and 10 millimeters in diameter offer ease in use, and simplicity in the application procedure. This study looked into the shear-bond behavior of FRP rods as compared to sheets. Direct tensile stresses were applied to test the shearbond between the sheets and rods, attached to a 35 MPa concrete surface. The failure behavior of the bond was also monitored. Additionally, the effectiveness of the embedded depth of the FRP rods relative to the concrete surface was also analyzed.

scholarly journals Bond-shear Behavior of FRP Rods as a Function of Attachment Configuration

2018 ◽  
Vol 1 (1) ◽  
pp. 9 ◽  
Author(s):  
Agung Budipriyanto ◽  
Ay Lie Han ◽  
Hsuan Teh Hu
Keyword(s):  
Influencing Factor ◽  
Concrete Surface ◽  
Concrete Cover ◽  
Shear Capacity ◽  
Fiber Reinforced Polymer ◽  
Failure Behavior ◽  
Embedment Depth ◽  
Reinforcement Scheme ◽  
Reinforced Polymer ◽  
External Reinforcement

The use of external reinforcement to improve or enhances the flexural capacity of a member depends on the transfer capacity, and the failure behavior of the composite between the reinforcement, the epoxy resin and the concrete. The most influencing factor is the bond-shear capacity between the rod and the epoxy, and the epoxy to the concrete. Fiber Reinforced Polymer (FRP) rods are the latest alternate for fulfilling the external reinforcement scheme. In the field, the mandated embedment depth as outlined by the ACI 440 code, could customary not be achieved since factors such as the depth of the concrete cover, and presence of stirrups limits the space. This study is aimed to evaluate the effect of FRP rod configurations with respect to the concrete surface, to the effectiveness of external reinforcement. The study looked into the bond-shear capacity as well as the mode of failure, influence by the rod attachment depth. It was shown that the embedment depth significantly influenced the failure mode, and therefore the strain transfer capacity from the concrete to the rods.

scholarly journals Delamination mechanism of GFRP sheet bonded on the reinforced concrete beams

2019 ◽  
Vol 258 ◽  
pp. 03009 ◽  
Author(s):  
Rudy Djamaluddin ◽  
Hijriah ◽  
Rita Irmawati ◽  
Faharuddin ◽  
Rossy T. Wahyuningsih
Keyword(s):  
Concrete Beams ◽  
Concrete Surface ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Bending Test ◽  
Four Point Bending ◽  
Reinforced Polymer ◽  
Direct Tensile ◽  
Bonding Characteristics ◽  
Surface Glass

Fiber reinforced polymer (FRP) has been developed to be applied for a strengthening of the deteriorated structures. In the form of a sheet, the FRP may be applied for the strengthening of the structures by bonding it to the concrete surface. Glass composed FRP (GFRP) sheet is most commonly used due to its relatively lower cost compared to the other FRP materials. GFRP sheet is applied externally by bonding it on the concrete surface. The strengthened structures should be monitored periodically to ensure the health of the strengthened structures. Regarding the development of monitoring system of the strengthened structure, it is important to study the delamination phenomenon of the bonded GFRP. Therefore the delamination mechanism is important to be clarified. Many studies have been done to investigate the bonding characteristics of GFRP sheet under direct tensile loading. However, the studies on the bonding characteristics of GFRP sheet on the strengthened beams due to flexural loadings are still limited. A series of concrete beams strengthened with GFRP sheet on extreme tension surface were prepared. The beam specimens ware loaded under four-point bending test gradually up to the ultimate capacity. Results indicated that prior to final delamination, a local delamination occurred which was indicated by the suddenly decreasing of an applied load. The delamination of the GFRP sheet may be initiated by the flexural cracks occurred on the beams.

EFFECT OF WET-DRY CYCLING ON BOND BEHAVIOR OF GFRP STRENGTHENED HISTORIC MASONRY STRUCTURES

2016 ◽  
Vol 78 (5-2) ◽  
Author(s):  
Meng Jing ◽  
Werasak Raongjant
Keyword(s):  
Research Work ◽  
Fiber Reinforced Polymer ◽  
Masonry Structures ◽  
Test Results ◽  
Bond Behavior ◽  
Historic Masonry ◽  
Water Permeation ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Cycling Condition

The objective of this research work is to determine the effect of wet-dry cycling on bond behavior of historic masonry structures strengthened by Glass Fiber Reinforced Polymer (GFRP). Shear bond testing was carried out through total 36 specimens exposed to dry, full moisture or wet-dry cycling conditions.  The selected samples were then tested at 0, 30, 60 and 90 days. Post-ageing test was also preceded on total sixty masonry prisms exposed to dry, full moisture or wet-dry cycling conditions. The compressive strengths of selected samples were then tested at 0, 40, 70 and 100 days. The test results showed an obvious decrease of the bond strength between GFRP sheets and bricks in the wet-dry cycling condition. For masonry prisms with or without GFRP strengthening, in the first 40 days, the compressive strength of GFRP bonded prism decreased quickly to the value near that of prism without GFRP. After 40 days the rate of decrease became slow, which means that, sheets retrofitted outside the masonry prisms helped to improve their durability by reducing water permeation. 

Assessing of Mechanical Properties of Natural Fiber Reinforced Polymer Matrix Hybrid Composites

2015 ◽  
Vol 766-767 ◽  
pp. 199-204 ◽  
Author(s):  
Kumar Jayachandran Nirmal ◽  
D. Premkumar
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Natural Fiber ◽  
Volume Fraction ◽  
Hybrid Composites ◽  
Natural Fibres ◽  
Fiber Reinforced Polymer ◽  
Resin Matrix ◽  
Reinforced Polymer ◽  
Individual Type

An experimental analysis has been carried out to investigate the mechanical properties of composites reinforced by sisal, coir, and banana fibres into epoxy resin matrix. The natural fibres were extracted by retting and manual processes. The composites fabricated by epoxy resin and reinforcement in the hybrid combination of Sisal-Banana and Sisal-Coir with the volume fraction of fibres varying from 5% to 30%. It has been identified that the mechanical properties increase with the increase of volume fraction of fibres to a certain extent and then decreases. The hybridization of the reinforcement in the composite shows greater mechanical properties when compared to individual type of natural fibres reinforced. For all the composites tested, the tensile strength of the composite increased up to 25% of volume fraction of the fibres and further for the increase in the volume fraction of fibre the mechanical properties were decreased. As same as tensile properties, the flexural and impact strength also increased linearly up to 25% of volume fraction of fibres and further for the increase in the volume fraction of fibre the mechanical properties were slightly decreased. Key Words: Sisal, Banana, Coir, Epoxy, Hybrid composite.

scholarly journals Size effect on the methodology with cylinder specimens for FRP-to-concrete debonding analysis

2021 ◽  
Vol 14 (3) ◽  
Author(s):  
Luana Ferreira Borges ◽  
Antonio Carlos dos Santos
Keyword(s):  
Size Effect ◽  
Failure Modes ◽  
Tensile Force ◽  
Size Variation ◽  
Concrete Specimen ◽  
Three Dimensions ◽  
Tensile Failure ◽  
Interface Failure ◽  
Reinforced Polymer ◽  
Direct Tensile

Abstract This is a study about the size effect on the methodology with concrete cylinder specimens for analysis of the debonding phenomenon at the interface between concrete and carbon fiber reinforced polymer (FRP). The influence of the concrete specimen size variation is analyzed by maintaining the same geometry in adhered FRP. Direct tensile experiments were performed with three dimensions of cylindrical concrete specimens (diameter × height) for analysis of size effect: 50 mm × 100 mm, 100 mm × 200 mm, and 150 mm × 300 mm. Ten different geometries of the composite material were tested. Two failure modes were observed in the experiments: debonding between the two materials and tensile failure in concrete specimens. In experiments with interface failure, the size of concrete specimens has no significant influence on maximum force, shear stress to peak, and stiffness in debonding between concrete and FRP. However, the use of smaller specimens for analysis of interface collapse is limited because the concrete reaches its normal stress capacity with a lower tensile force, and therefore, the failure often occurs in the concrete.

Sign in / Sign up

Export Citation Format

Share Document