scholarly journals Experimental Study on Strengthening of RC Short Columns with BFRP Sheets

2018 ◽  
Vol 7 (3.12) ◽  
pp. 48
Author(s):  
Arathi Krishna ◽  
Milu Mary Jacob ◽  
K Saravana Raja Mohan
Keyword(s):  
Experimental Studies ◽  
Basalt Fiber ◽  
Load Condition ◽  
Primary Objective ◽  
Fiber Reinforced Polymer ◽  
Analytical Models ◽  
Fiber Reinforced ◽  
Short Columns ◽  
Reinforced Polymer ◽  
Materials Used

Earlier the methods adopted for the repair and rehabilitation were the external bonding of the damaged component with steel fibers and steel jackets. But the major problem that caused due to this steel components is corrosion. Fiber Reinforced Polymer (FRP) composite materials used for strengthening of components in the form of confinement is of considerable importance in civil engineering. This paper presents the results of axially loaded RC short columns which are strengthened by providing confinement with new material BFRP. The primary objective of this work is to examine the load carrying capacity of concrete columns confined with basalt fiber reinforced polymer jacket (BFRP) which is considered as an abstruse material for strengthening. BFRP materials are non-corrosive, non-magnetic, and chemical resistant and they are progressively being used for repair, rehabilitation, and strengthening of structures that are not stable enough to carry loads. The parameters considered in the study are full and partial wrapping and the number of layers of confinement. The results obtained from the experimental studies and the analytical models precisely shows that the BFRP confinements will upgrade the compressive strength of columns under the given load condition.

Compressive Behavior of Circular Concrete Columns Confined by Basalt Fiber Reinforced Polymer (BFRP)

2018 ◽  
Vol 765 ◽  
pp. 355-360 ◽  
Author(s):  
Sakol Suon ◽  
Shahzad Saleem ◽  
Amorn Pimanmas
Keyword(s):  
Basalt Fiber ◽  
Concrete Columns ◽  
Primary Objective ◽  
Fiber Reinforced Polymer ◽  
Small Scale ◽  
Fiber Reinforced ◽  
Compressive Behavior ◽  
Reinforced Polymer ◽  
Ductile Behavior ◽  
Basalt Fiber Reinforced Polymer

This paper presents an experimental study on the compressive behavior of circular concrete columns confined by a new class of composite materials originated from basalt rock, Basalt Fiber Reinforced Polymer (BFRP). The primary objective of this study is to observe the compressive behavior of BFRP-confined cylindrical concrete column specimens under the effect of different number of layers of basalt fiber as a study parameter (3, 6, and 9 layers). For this purpose, 8 small scale circular concrete specimens with no internal steel reinforcement were tested under monotonic axial compression to failure. The results of BFRP-confined concrete specimens of this study showed a bilinear stress-strain response with two ascending branches. Consequently, the performance of confined columns was improved as the number of BFRP layer was increased, in which all the specimens exhibited ductile behavior before failure with significant strength enhancement. The experimental results indicate the well-performing of basalt fiber in improving the concrete compression behavior with an increase in number of FRP layers.

scholarly journals The analysis of crack width in flexural concrete members reinforced with polymer composite bars

Vestnik MGSU ◽  
2020 ◽  
pp. 1663-1672
Author(s):  
Ilshat T. Mirsayapov ◽  
Igor A. Antakov ◽  
Alexey B. Antakov
Keyword(s):  
Crack Width ◽  
Experimental Studies ◽  
Basalt Fiber ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Calculation Methods ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Frp Reinforcement

Introduction. Rebars, made of fiber-reinforced polymers (FRP), have a number of distinguishing characteristics and disadvantages along with well-known strengths, such as high tensile strength, low specific density, high corrosion resistance, and low thermal conductivity. One of its principal strengths is the modulus of elasticity which is relatively low compared to steel. As a result, elements, having FRP reinforcement, feature higher deformability. In this regard, the requirements of serviceabi-lity limit states, applicable to structures, may become the main obstacle to the use of FRP as the reinforcement for concrete members. It is assumed that cracking patterns of members, having FRP reinforcement, may differ from those of traditional reinforced concrete structures. Materials and methods. Experimental studies were carried with regard for and in compliance with the provisions of National State Standard 8829-94. Tested samples represented concrete beams that were 1,810 mm long and had a cross section of 120 × 220 mm. Their tensile side was reinforced with two bars. Steel, glass fiber-reinforced polymer (GFRP) and basalt fiber-reinforced polymer (BFRP) bars were used to reinforce the beams. The value of the reinforcement ratio varied. Crack width calculation methods, applied according to Construction rules and regulations 63.13330.2012 and 295.1325800.2017 (Russia) and ACI 440.1R-06 (USA) were analyzed. Results. The results of the theoretical and experimental studies of the crack resistance of flexural members having FRP reinforcement are obtained. Discrepancies between the calculation methods are identified. Conclusions. Сracking patterns, typical for members having FRP reinforcement, are specified. They contest the applicabi-lity of methods, prescribed in the Construction Rules and Regulations. The methods, prescribed by Construction Rules and Regulations 63.13330.2012 and 295.1325800.2017, differ in respect of crack width calculations, and it leads to diverging calculation results.

scholarly journals Durability and Mechanical Properties of Concrete Reinforced with Basalt Fiber-Reinforced Polymer (BFRP) Bars: Towards Sustainable Infrastructure

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1402
Author(s):  
Osama Ahmed Mohamed ◽  
Waddah Al Hawat ◽  
Mohammad Keshawarz
Keyword(s):  
Carbon Steel ◽  
Experimental Studies ◽  
Basalt Fiber ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Sustainable Infrastructure ◽  
Reinforced Polymer ◽  
Reinforced Beams ◽  
Minimal Environmental Impact ◽  
Basalt Fiber Reinforced Polymer

Reducing the fingerprint of infrastructure has become and is likely to continue to be at the forefront of stakeholders’ interests, including engineers and researchers. It necessary that future buildings produce minimal environmental impact during construction and remain durable for as long as practicably possible. The use of basalt fiber-reinforced polymer (BFRP) bars as a replacement for carbon steel is reviewed in this article by examining the literature from the past two decades with an emphasis on flexural strength, serviceability, and durability. The provisions of selected design and construction guides for flexural members are presented, compared, and discussed. The bond of BFRP bars to the surrounding concrete was reportedly superior to carbon steel when BFRP was helically wrapped and sand coated. Experimental studies confirmed that a bond coefficient kb = 0.8, which is superior to carbon steel, may be assumed for sand-coated BFRP ribbed bars that are helically wrapped, as opposed to the conservative value of 1.4 suggested by ACI440.1R-15. Code-based models overestimate the cracking load for BFRP-reinforced beams, but they underestimate the ultimate load. Exposure to an alkaline environment at temperatures as high as 60 °C caused a limited reduction in bond strength of BFRP. The durability of BFRP bars is influenced by the type of resin and sizing used to produce the bars.

scholarly journals To the design of the deflections of flexural concrete members reinforced with fiber-reinforced polymer bars

Vestnik MGSU ◽  
2021 ◽  
pp. 413-428
Author(s):  
Ilshat T. Mirsayapov ◽  
Igor A. Antakov ◽  
Alexey B. Antakov
Keyword(s):  
Experimental Studies ◽  
Basalt Fiber ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced Polymers ◽  
Strain Diagram ◽  
Fiber Reinforced ◽  
Calculation Methods ◽  
Short Term ◽  
Reinforced Polymer ◽  
Frp Reinforcement

Introduction. Fiber-reinforced polymers (FRP) reinforcement has a relatively low modulus of elasticity compared to steel. In this connection, the bent members with such reinforcement have a higher deformability. The stress-strain diagram for FRP under short-term loading is almost straight and does not have a yield line, as in steel reinforcement. At the same time, modern methods of calculating structures with for FRP reinforcement are based on existing approaches for reinforced concrete structures. In this regard, the current direction for study is to assess the reliability and improve the existing methods for calculating members with FRP reinforcement for the serviceability limit states. Materials and methods. Experimental studies were carried with regard for and in compliance with the provisions of National State Standard 8829-94. Tested samples represented concrete beams that were 1,810 mm long and had a cross section of 120 × 220 mm. Their tensile side was reinforced with two bars. Steel, glass fiber-reinforced polymer (GFRP) and basalt fiber-reinforced polymer (BFRP) bars were used to reinforce the beams. The value of the reinforcement ratio varied. Deflections calculation methods, applied according to Construction rules and regulations 295.1325800.2017 (Russia) and ACI 440.1R-06 (USA) were analyzed. Results. The results of the theoretical and experimental studies of the deformability of flexural members having FRP reinforcement are obtained. The inaccurate determination of the cracking moment Mcrc has a negative impact on the results of the deflection calculation. The deviation of the theoretical values of the cracking moment according to the method of Construction rules and regulations 295.1325800.2017 from the experimental ones is 26.2–59.1 %, in the method of ACI 440.1 R-06 — 20.1–57.1 %. For the ACI 440.1 R-06 method, the calculation is more accurate, in which the short-term deflection was multiplied by the factor λ = 0,6ξ = 0,6 · 2 = 1,2, for the Construction rules and regulations 295.1325800.2017 method — when using ψf = 1 – 0,8Mcrc / M. Conclusions. The results obtained showed the need to improve the considered calculation methods. To increase the accuracy of the calculation of deflections according to the method of SP 295.1325800.2017, at the first stage, it is possible to approximate the theoretical values of the cracking moment to the experimental data by introducing correction factor in the equation according to the calculation of Mcrc: for beams with a GFRP high-bond bars — 0.7, for BFRP with a sanded surface — 0.5.

scholarly journals Compressive Strength of Modified FRP Hybrid Bars

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1898
Author(s):  
Marek Urbański
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Basalt Fiber ◽  
Test Method ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Free Length ◽  
Compression Properties ◽  
Reinforced Polymer ◽  
Frp Bars

A new type of HFRP hybrid bars (hybrid fiber reinforced polymer) was introduced to increase the rigidity of FRP reinforcement, which was a basic drawback of the FRP bars used so far. Compared to the BFRP (basalt fiber reinforced polymer) bars, modification has been introduced in HFRP bars consisting of swapping basalt fibers with carbon fibers. One of the most important mechanical properties of FRP bars is compressive strength, which determines the scope of reinforcement in compressed reinforced concrete elements (e.g., column). The compression properties of FRP bars are currently ignored in the standards (ACI, CSA). The article presents compression properties for HFRP bars based on the developed compression test method. Thirty HFRP bars were tested for comparison with previously tested BFRP bars. All bars had a nominal diameter of 8 mm and their nonanchored (free) length varied from 50 to 220 mm. Test results showed that the ultimate compressive strength of nonbuckled HFRP bars as a result of axial compression is about 46% of the ultimate strength. In addition, the modulus of elasticity under compression does not change significantly compared to the modulus of elasticity under tension. A linear correlation of buckling load strength was proposed depending on the free length of HFRP bars.

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