scholarly journals The Influence of the Curing Conditions on the Behavior of Jute Fibers Reinforced Concrete Cylinders

Author(s):  
Yasmina Ed-Dariy ◽  
Nouzha Lamdouar ◽  
Toufik Cherrad ◽  
Ancuta Rotaru ◽  
Marinela Barbuta ◽  
...  

This paper presents an innovative method of reinforcement of concrete based on the use of the Jute fibers composites. These renewable raw bioresource fibers are available at a low cost. Moreover, they can be compared to Glass Fiber-Reinforced Polymer (GFRP) by enhancing the resistance of Jute Fiber-Reinforced Polymer (JFRP), while improving the compatibility between the fiber and the resin. For that purpose, this paper presents an experimental study that evaluates the influence of the curing conditions (time and temperature) on the behavior of JFRP laminates and concrete members strengthened by JFRP. The curing conditions at 30 °C for 2h 30min and at 50 °C for 1 h were the only two parameters studied and determined on the basis of Sikadur 330 properties and preliminary tests. Through the experimental tests, the maximum load capacity and observed failure modes are investigated. The results indicated that the curing at 30 °C for 2h 30min is the optimum curing condition. In addition, a low difference in the maximum load capacity was noted in the case of 50 °C. As to the failure modes, all the specimens cured with additional heat before being left under room conditions, have shown the ductile mode failure, especially in the case of specimens cured at 30 °C during 2h 30min. The analytical model conducted in this paper predicts the elastic modulus depending on temperature. The obtained results and proposed model can be used as input parameters in the analysis and design of externally strengthened members with Jute FRP composites.

2019 ◽  
Vol 258 ◽  
pp. 03002
Author(s):  
Torang Sitorus ◽  
Silvy Desharma

Flexural reinforcement on wood beams is intended to increase the maximum load capacity that can be supported by wood beams until they are collapse. One of the most widely used resilient reinforcements currently used is reinforcement using Carbon Fiber Reinforced Polymer (CFRP) which is a combination of high strength with light weight material. This reinforcement is intended for historical buildings that need more load capacity that can be supported due to changes in building function, or the increase of the load on the building. The purpose of this research is to know the effect of reinforcement of wood beams with CFRP and variation of length of reinforcement to flexible strength of wood beams, and beam behavior reinforced with CFRP due to loading. Structural beam testing using mahogany logs with cross sectional size 75x100mm2 along 2 m consisting of 4 types of samples with each type consists of 2 pieces of sample. The first sample was a wood beams without reinforcement, the second sample was a wood beams with a reinforcing length of ¼ spans in the middle, a third sample was a wood beams with a reinforcing length ¾ spans in the middle, and a fourth sample was a wood beams with retrofitting along the length of the span. From the test it is found that the maximum load increase that can be supported by the sample with the length of reinforcement ¼ span, ¾ span, and along the span has increased the maximum load respectively that is 4.393%, 37.340%, and 48.323% compared to wood beams without reinforcement. The average damage occurring in samples with CFRP is debonding failure.


2006 ◽  
Vol 324-325 ◽  
pp. 995-998
Author(s):  
Cheol Woo Park ◽  
Jong Sung Sim

Even though the application of fiber reinforced polymer (FRP) as a concrete reinforcement becomes more common with various advantages, one of the inherent shortcomings may include its brittleness and on-site fabrication and handling. Therefore, the shape of FRP products has been limited only to a straight bar or sheet type. This study suggests a new technique to use glass fiber reinforced polymer (GFRP) bars for the shear reinforcement in concrete beams, and investigates its applicability. The developed GFRP stirrup was used in the concrete instead of ordinary steel stirrups. The experimental program herein evaluates the effectiveness of the GFRP stirrups with respect to different shear reinforcing ratios under three different shear span-to-depth testing schemes. At the same shear reinforcing ratio, the ultimate loads of the beams were similar regardless the shear reinforcing materials. Once a major crack occurs in concrete, however, the failure modes seemed to be relatively brittle with GFRP stirrups. From the measured strains on the surface of concrete, the shear stresses sustained by the stirrups were calculated and the efficiency of the GFRP stirrups was shown to be 91% to 106% depending on the shear span-to-depth ratio.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Sang-Pyuk Woo ◽  
Sun-Hee Kim ◽  
Soon-Jong Yoon ◽  
Wonchang Choi

Bolt-hole clearance affects the failure mode on the bolted connection system of pultruded fiber-reinforced polymer plastic (PFRP) members. The various geometric parameters, such as the shape and cross-sectional area of the structural members, commonly reported in many references were used to validate the bolt-hole clearance. This study investigates the effects of the bolt-hole clearance in single-bolt connections of PFRP structural members. Single-bolt connection tests were planned using different bolt-hole clearances (e.g., tight-fit and clearances of 0.5 mm to 3.0 mm with 0.5 mm intervals) and uniaxial tension is applied on the test specimens. Most of the specimens failed in two sequential failure modes: bearing failure occurred and the shear-out failure followed. Test results on the bolt-hole clearances are compared with results in the previous research.


2020 ◽  
Vol 10 (7) ◽  
pp. 2489 ◽  
Author(s):  
Francesca Sciarretta

This paper presents a study on the potentiality of seismic retrofitting solutions with pultruded Fiber Reinforced Polymer (FRP) profiles. This material can be used in connected frames providing lightweight, corrosion-free and reversible retrofitting of masonry buildings with the moderate requirements of surface preservation. In a hypothetical case study, an experimental program was designed; monotonic shear tests on a half-size physical model of the sample wall were performed to assess the structural performance before and after retrofitting with a basic frame of pultruded Glass Fiber Reinforced Polymer (GFRP) C-shaped profiles, connected to the masonry by steel threaded bar connections. During the tests, the drift, the diagonal displacements in the masonry and the micro-strain in the profiles were measured. The retrofitted system has proven very effective in delaying crack appearance, increasing the maximum load (+85% to +93%) and ultimate displacement (up to +303%). The failure mode switches from rocking to a combination of diagonal cracking and bed joint sliding. The gauge recordings show a very limited mechanical exploitation of the GFRP material, despite the noticeable effectiveness of the retrofit. The application seems thus promising and worth a deeper research focus. Finally, a finite element modelling approach has been developed and validated, and it will be useful to envisage the effects of the proposed solution in future research.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Bo Wen ◽  
Chunfeng Wan ◽  
Lin Liu ◽  
Da Fang ◽  
Caiqian Yang

Fatigue behavior is an important factor for mechanical analysis of concrete members reinforced by basalt fiber reinforced polymer (BFRP) grid and polymer cement mortar (PCM) and plays a critical role in ensuring the safety of reinforced concrete bridges and other structures. In this study, on the basis of the static loading test results of concrete specimens reinforced by BFRP grid and PCM, a series of fatigue tests with different loading levels were conducted on interfaces between BFRP grid and concrete to investigate the fatigue behavior of BFRP grid-concrete interfaces. The test results indicate that with high loading level, the fatigue failure mode of interface is interfacial peeling failure while it transforms to the fatigue fracture of the BFRP grid under low loading level. The fatigue life (S-N) curves of BFRP grid-concrete interface are obtained and fitted in stages according to different failure modes, and the critical point of the two failure modes is pointed out. The relative slip evolution of interface during fatigue is further revealed in different stages with two failure modes, and the law of interface strain is studied with the increase of fatigue times. The relation of effective bonding length of interface and fatigue times is also described.


2020 ◽  
Vol 23 (13) ◽  
pp. 2911-2927
Author(s):  
Yung William Sasy Chan ◽  
Zhi Zhou ◽  
Zhenzhen Wang ◽  
Jinping Ou

Fiber-reinforced polymer composites have been widely used to design fiber-reinforced polymer–based confined concrete columns with potential benefits. However, it is critical to design a column with sufficient post-peak performance that can prevent its collapse at the rupture of the fiber-reinforced polymer tube. This article presents the experimental results on the prior and post peaks behavior of concrete-filled double-skin tubular columns with basalt fiber-reinforced polymer (BFRP)–punched-in outer steel and BFRP-circular inner steel (BFST-DSTCs). Twenty-two specimens were tested under axial compression to investigate the effects of design parameters on the behavior of the BFST-DSTC. The outcomes reveal that the BFST-DSTC exhibits the best performance in terms of load capacity, confinement ratio, failure and damage mechanisms, and ductility in prior and post peaks. The inner fiber-reinforced polymer jacket delays the buckling of the inner tube. The punched-in patterns of the outer steel improve the confinement effectiveness of the fiber-reinforced polymer jacket. The BFST-DSTC displays a good post-peak performance with high-energy dissipation capacity that prevents the concerned structure from collapse after the fiber-reinforced polymer jacket rupture. Finally, a new confinement model is proposed to predict the ultimate point of the confined concrete.


‘Concrete Filled Steel Tubes (CFST)’/ ‘Concrete Filled FRP Tubes (CFFT)’ comprises of a steel/ ‘Fiber Reinforced Polymer (FRP)’ hollow pipe of circular or rectangular shape filled with plain or reinforced concrete. Need of such composite columns in the field of building construction is due to advancements in technology, need of bigger space in smaller land area, ease in construction workability, and a lot of other modern time requirements. This paper defines an experimental and computational project carried out by testing a total of 49 CFST columns and 60 CFFT columns. Three Finite Element models were also made using the software pack ABAQUS. Variables for the study were aspect ratio of columns, Shape of columns (i.e. square, circular or rectangular) and material (i.e. steel or FRP). Basic aim of the project was to find structural parameters like load-deflection behaviour, deflection pattern, maximum load carrying capacity etc. The Steel reinforced concrete-filled fiber reinforced polymer (FRP)tubular column is proposed as a new form of composite column to obtain higher mechanical performance. A comparative analysis was also carried out using three main resulting indices like Ductility Index (DI), Strength Index (SI) and Concrete Contribution Ratio (CCR). Comparative observations between CFST/CFFT columns of different shapes and sizes is carried out, also experimental results were compared with analytical results obtained from ABAQUS software.


2017 ◽  
Author(s):  
Parmo

Wheres Indonesia is a highly active tectonic zone that is prone to earthquakes. Important issue following the earthquake was retrofit structures to improvement strength and ductility structure. With the advancement of technology today has developed new innovations such as the use of material GFRP (Glass Fiber Reinforced Polymer) for external confinement structure. From the results obtained by the experimental of load capacity increased by 20% for C-2 (retrofit beam with GFRP strengthened 1 layer) compared B-1 (original beam). Retrofit beam with GFRP is added ductility as shown by the increase in displacement ductility 4% each for B-1 and B-2.


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