scholarly journals Experimental Study on the Performance of Frp Tendon Anchoring Devices in Axial Tension

2020 ◽  
Vol 15 (3) ◽  
pp. 135-143
Author(s):  
Ivan V. Abramov ◽  
Pavel V. Lekomtsev ◽  
Аlexander V. Romanov ◽  
Аndrey V. Buchkin ◽  
Zarina S. Saidova ◽  
...  
Keyword(s):  
Experimental Study ◽  
Tensile Strength ◽  
Experimental Research ◽  
Load Capacity ◽  
Tensile Tests ◽  
Strength Properties ◽  
Fiber Reinforced Polymer ◽  
Stress Range ◽  
Axial Tension ◽  
Reinforced Polymer

The paper presents an experimental research on anchoring devices developed for the pre-tensioning of fiber reinforced polymer tendons in the stress range between 40 and 70% of tensile strength. The technique of testing, the criteria of assessing the load capacity and the influence of preloading applied on the anchor wedges on the initial tendons slippage are described. The optimal technical configurations of the anchoring device have been obtained, including parameters regarding the necessary prior anchorage of the tendon ends based on the strength properties of the tendon bar and the requirements to avoid slippage during the tensile tests.

scholarly journals Experimental Study of the Probabilistic Fatigue Residual Strength of a Carbon Fiber-Reinforced Polymer Matrix Composite

2020 ◽  
Vol 4 (4) ◽  
pp. 173
Author(s):  
Xiang-Fa Wu ◽  
Oksana Zholobko
Keyword(s):  
Experimental Study ◽  
Tensile Strength ◽  
Carbon Fiber ◽  
Cyclic Loading ◽  
Polymer Matrix ◽  
Residual Strength ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

Degradation of the mechanical properties of fiber-reinforced polymer matrix composites (PMCs) subjected to cyclic loading is crucial to the long-term load-carrying capability of PMC structures in practice. This paper reports the experimental study of fatigue residual tensile strength and its probabilistic distribution in a carbon fiber-reinforced PMC laminate made of unidirectional (UD) carbon-fiber/epoxy prepregs (Hexcel T2G190/F263) with the ply layup [0/±45/90]S after certain cycles of cyclic loading. The residual tensile strengths of the PMC laminates after cyclic loading of 1 (quasistatic), 2000, and 10,000 cycles were determined. Statistical analysis of the experimental data shows that the fatigue residual tensile strength of the PMC laminate follows a two-parameter Weibull distribution model with the credibility ≥ 95%. With increasing fatigue cycles, the mean value of the fatigue residual strength of the PMC specimens decreased while its deviation increased. A free-edge stress model is further adopted to explain the fatigue failure initiation of the composite laminate. The present experimental study is valuable for understanding the fatigue durability of PMC laminates as well as reliable design and performance prediction of composite structures.

Effects of Slit Patterns on the Tensile Properties of Unidirectionally Arrayed Chopped Strands Composites

2013 ◽  
Vol 750 ◽  
pp. 208-211
Author(s):  
Hang Li ◽  
Wen Xue Wang ◽  
Yoshihiro Takao ◽  
Terutake Matsubara
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Tensile Properties ◽  
Failure Modes ◽  
Tensile Tests ◽  
Short Fiber ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer

This study investigates the tensile properties of UACS (unidirectional arrayed chopped strands) laminates with different slit patterns. UACS composite is a kind of short fiber reinforced polymer by introducing slits into prepregs before the fabrication of laminates. Existing UACS composites have superior flowability but relatively low tensile strength compared to conventional CFRP (carbon fiber reinforced polymer). Consequently, many efforts have been made to improve the strength of UACS composites. In this study, two new discontinuous slit patterns, staggered pattern and bi-angled pattern, have been developed. Tensile tests reveal that two new UACS laminates with staggered and bi-angled slit patterns have higher strength and higher stiffness than existing UACS laminates with continuous slits. Discontinuity of slits plays an important role in inhibiting the development of delamination. Different slit patterns show different failure modes.

scholarly journals Significance of Tungsten Carbide Filler Reinforcement on Ultimate Tensile Strength of Basalt Fiber Epoxy Composites

2019 ◽  
Vol 8 (3) ◽  
pp. 7913-7916
Keyword(s):  
Tensile Strength ◽  
Tungsten Carbide ◽  
Basalt Fiber ◽  
Strength Properties ◽  
Fiber Reinforced Polymer ◽  
Epoxy Composites ◽  
Fiber Reinforced ◽  
Synthetic Fibers ◽  
Reinforced Polymer ◽  
Twill Weave

Basalt Fiber Reinforced polymer composite has the best green reinforced alternative to synthetic fibers. It is having an excellent mechanical properties compared to synthetic fibers. Twill weave woven basalt fabric used to manufacture the laminates using Hand layup method preceded with vacuum bag pressure method to obtain the series of unfilled and filled tungsten carbide filler (0-8%) materials into basalt epoxy composites. In this study, tensile strength and percentage of elongation of laminated structure carried out using computerized universal testing equipment. Among these laminates, the basalt fiber reinforced with 6% of tungsten carbide filler shows better strength properties than the other combination of laminates. The incorporation of tungsten carbide fillers in epoxy composites could provide a synergism in terms of improving tensile properties and percentage of elongation

scholarly journals Neural Networks—Deflection Prediction of Continuous Beams with GFRP Reinforcement

2021 ◽  
Vol 11 (8) ◽  
pp. 3429
Author(s):  
Željka Beljkaš ◽  
Nikola Baša
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Artificial Neural Networks ◽  
Experimental Research ◽  
Fiber Reinforced Polymer ◽  
Glass Fiber Reinforced Polymer ◽  
Reinforced Polymer ◽  
Continuous Beams ◽  
Glass Fiber Reinforced ◽  
Gfrp Reinforcement

Deflections on continuous beams with glass fiber-reinforced polymer (GFRP) reinforcement are calculated in accordance with the appropriate standards (ACI 440.1R-15, CSA S806-12). However, experimental research provides results which differ from the values calculated pursuant to the standards, particularly when it comes to continuous beams. Machine learning methods can be applied for predicting a deflection level on continuous beams with GFRP (glass fiber-reinforced polymer) reinforcement and loaded with a concentrated load. This paper presents research on using artificial neural networks for deflection estimation and an optimal prediction model choice. It was necessary to first develop a database, in order to train the neural network. The database was formed based on the results of the experimental research on continuous beams with GFRP reinforcement. Using the best trained neural network model, high accuracy was obtained in estimating deflection, expressed over the mean absolute percentage error, 9.0%. This result indicates a high level of reliability in the prediction of deflection with the help of artificial neural networks.

Utilizing alkali-activated materials as ordinary Portland cement replacement to study the bond performance of fiber-reinforced polymer bars in seawater sea-sand concrete

2022 ◽  
pp. 136943322110651
Author(s):  
Ruiming Cao ◽  
Bai Zhang ◽  
Luming Wang ◽  
Jianming Ding ◽  
Xianhua Chen
Keyword(s):  
Tensile Strength ◽  
Bond Strength ◽  
Ordinary Portland Cement ◽  
Concrete Strength ◽  
Fiber Reinforced Polymer ◽  
Bond Performance ◽  
Reinforced Polymer ◽  
Sea Sand ◽  
Frp Bars ◽  
Alkali Activated

Alkali-activated materials (AAMs) are considered an eco-friendly alternative to ordinary Portland cement (OPC) for mitigating greenhouse-gas emissions and enabling efficient waste recycling. In this paper, an innovative seawater sea-sand concrete (SWSSC), that is, seawater sea-sand alkali-activated concrete (SWSSAAC), was developed using AAMs instead of OPC to explore the application of marine resources and to improve the durability of conventional SWSSC structures. Then, three types of fiber-reinforced polymer (FRP) bars, that is, basalt-FRP, glass-FRP, and carbon-FRP bars, were selected to investigate their bond behavior with SWSSAAC at different alkaline dosages (3%, 4%, and 6% Na2O contents). The experimental results manifested that the utilization of the alkali-activated binders can increase the splitting tensile strength ( ft) of the concrete due to the denser microstructures of AAMs than OPC pastes. This improved characteristic was helpful in enhancing the bond performance of FRP bars, especially the slope of bond-slip curves in the ascending section (i.e., bond stiffness). Approximately three times enhancement in terms of the initial bond rigidity was achieved with SWSSAAC compared to SWSSC at the same concrete strength. Furthermore, compared with the BFRP and GFRP bars, the specimens reinforced with the CFRP bars experienced higher bond strength and bond rigidity due to their relatively high tensile strength and elastic modulus. Additionally, significant improvements in initial bond stiffness and bond strength were also observed as the alkaline contents (i.e., concrete strength) of the SWSSAAC were aggrandized, demonstrating the integration of the FRP bars and SWSSAAC is achievable, which contributes to an innovative channel for the development of SWSSC pavements or structures.

RETROFITTING PERFORMANCE OF REINFORCED CONCRETE ONE WAY SLAB

2016 ◽  
Vol 78 (5-3) ◽  
Author(s):  
Norliyati Mohd Amin ◽  
Nur Aqilah Aziz ◽  
Ilya Joohari ◽  
Anizahyati Alisibramulisi
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Bending Test ◽  
Strength Performance ◽  
Concrete Crack ◽  
Reinforced Polymer ◽  
Structural Capacity

Cracks in concrete structure have always been a big threat on the strength of the concrete. Crack is one of the common deterioration observed in reinforced concrete beams and slabs. Concrete cracking is a random process, highly variable and influenced by many factors. To restore the structural capacity of the concrete damages, retrofitting and strengthening are required. There are several techniques that are used for retrofitting and strengthening reported in the literature [1], [2], [3]. This paper investigates the strength performance of retrofitting and strengthening methods of reinforced concrete one-way slab. Flexural bending test are performed on three different concrete slab of size 1000 mm x 500 mm x 75 mm. The methods that are used for retrofit are epoxy injection and patching and for the strengthening is lamination of carbon fiber reinforced polymer. The slabs were loaded to a certain stage where the cracks were formed for retrofitting and strengthening procedure. The achieved failure mode and load capacity of the concrete slab were observed. The repaired techniques for restoring and improving the structural capacity of cracked concrete slabs were analyzed. The ultimate load achieved for the epoxy injection laminate was 19.60 kN followed by CFRP laminate and patching that were 17.64 kN and 17.03 kN respectively. While the deflection value for the three specimens were 14.42 mm, 4.49 mm and 7.036 mm.  

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