Fracture patterns and mechanical properties of GFRP bars as internal reinforcement in concrete structures

2020 ◽  
Vol 11 (3) ◽  
pp. 69
Author(s):  
Mehmet Canbaz ◽  
Uğur Albayrak
Keyword(s):  
Mechanical Properties ◽  
Concrete Structures ◽  
Concrete Block ◽  
Glass Fiber Reinforced Plastic ◽  
Gfrp Bars ◽  
Steel Rebar ◽  
Pull Out ◽  
Steel Bars ◽  
Bonding Properties ◽  
Modulus Of Resilience

Glass Fiber Reinforced Plastic (GFRP) composites as rolled bars can be used as steel rebar to prevent oxidation or rust which is one of the main reasons concrete structures deteriorate when exposed to chlorides and other harmful chemicals. GFRP is successful alternative for reinforcement with high tensile strength- low strain, corrosion resistance and congenital electromagnetic neutrality in terms of longer service life. The main goal of the study is to investigate the mechanical and bonding properties of GFRP bars and equivalent steel reinforcing bars then compare them. GFRP and steel rebar are embedded in concrete block with three different levels. Mechanical properties of GFRP and steel bars in terms of strength and strains are determined. On the other hand; modulus of elasticity of GFRP and steel bars, modulus of toughness and modulus of resilience were calculated using stress-strain curves, as a result of the experiments. Pull-out tests are conducted on each GFRP and rebar samples which are embedded in concrete for each embedment level and ultimate adherence strengths are determined in terms of bar diameter–development length ratio. Yield strength, strain and modulus of elasticities of GFRP samples are compared to steel rebar. According to the test results reported in this study, GFRP bars are used safely instead of steel bars in terms of mechanical properties.

scholarly journals Examination of Reinforcement Steel Bars Exposed to the Atmosphere

2020 ◽  
pp. 1-5
Author(s):  
Adejo O H ◽  
◽  
Ojo S A ◽  
Uzuh F U ◽  
Abere D V ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Sodium Chloride ◽  
Concrete Structures ◽  
The Other ◽  
Reinforced Concrete Structures ◽  
Reinforcement Steel ◽  
Corrosion Rates ◽  
Steel Bars ◽  
Steel Rebars ◽  
Strength And Ductility

Reinforcement steel bars are often exposed to the atmosphere before use in concrete structures. This exposure results in corrosion of these reinforcement bars. Corrosion of reinforcement bars is a common form of degradation of reinforced concrete structures. The electrochemical attack affects the mechanical properties of steel rebars. This study analysed the effect of exposing reinforcing steel bars to the atmosphere. The bars were divided into two; one part was exposed to the atmosphere for a period of four months during the rainy season while the other was unexposed. Afterwards; some mechanical, corrosion and metallographic tests were carried out on the steel samples. The results obtained showed that the hardness, impact strength and ductility increased with exposure while the yield and tensile strengths decreased with exposure. The exposed bar had high corrosion rates than the unexposed bar in 1M hydrochloric acid (HCl) while in 1M sodium chloride (NaCl), the corrosion rates for both the exposed and unexposed bars did not follow a particular trend

Innovative Design of GFRP Bars for Concrete Structures

2012 ◽  
Vol 457-458 ◽  
pp. 553-556 ◽  
Author(s):  
Ana Almerich-Chulia ◽  
Pedro Martin-Concepcion ◽  
Jose Miguel Molines-Cano ◽  
Juan Rovira-Soler
Keyword(s):  
Mechanical Properties ◽  
Concrete Structures ◽  
Innovative Design ◽  
Gfrp Bars ◽  
Tension And Compression ◽  
Research Situation

This part analyzed GFRP rebar’s research situation, summarized its behaviuor as internal reinforcement for concrete structures. The research has been developed over recent years, however the rules and standard codes for design RC concrete structures with these rebars not consider that the internal reinforcement can work in compression. This paper presents the development of the research to get a new kind GFRP rebar for work as internal reinforcement of concrete structures, with an innovative design for work both in tension and compression, and their mechanical properties: strength, bond,…

Experimental Bond Behavior of Mortar Grouted GFRP Rock Bolt

2011 ◽  
Vol 261-263 ◽  
pp. 1244-1248 ◽  
Author(s):  
Qi Neng Weng ◽  
Yong Yuan ◽  
Qian Guan Zhang
Keyword(s):  
Rock Mass ◽  
Concrete Block ◽  
Rock Bolt ◽  
Rock Bolts ◽  
Engineering Structures ◽  
Bond Behavior ◽  
Gfrp Bars ◽  
Pull Out ◽  
Glass Fiber Reinforced ◽  
Concrete Blocks

Bolts are widely used in slope engineering, tunnel and large cave supporting structures, as well as restoration of engineering structures. They can improve the strength and stability of ground, rock mass, and other structures. The traditional steel bolt has some disadvantages, such as easy corrosion, heavy weight, and difficult operation. Glass Fiber Reinforced Polymer (GFRP) is more resistant to chloride, stronger and lighter than steel. Those advantages make it a better alternative in some fields of engineering. To utilize GFRP bars as rock bolt, some aspects of its behavior, such as bond strength in mortar, bearing capacity, and bond stress distributing along its interface, have to be examined. This paper presents a research on bond behavior of GFRP rock bolts. A concrete block is used to represent rock mass in laboratory. Modified pull out tests were conducted on selected GFRP bars and compared with steel ones that were grouted with mortar in concrete blocks. Bond characteristics of mortar grouted GFRP rock bolts with diameter 16mm were mainly evaluated and other specs of bolts were also discussed.

scholarly journals Efecto del mantequillado en las propiedades mecánicas de uniones soldadas disímiles en barras de refuerzo para estructuras de concreto.

2016 ◽  
Vol 6 (3) ◽  
pp. 248-261
Author(s):  
J. C. I. Ramírez-Soto ◽  
J. M. Salgado-López ◽  
J. T. Pérez-Quiroz ◽  
T. Pérez-López ◽  
J. Terán-Guillén ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Microstructural Analysis ◽  
Concrete Structures ◽  
Tensile Tests ◽  
Plain Carbon Steel ◽  
Dissimilar Metal ◽  
Weld Joints ◽  
Steel Bars ◽  
Dissimilar Metal Weld ◽  
Metal Weld

Efecto del mantequillado en las propiedades mecánicas de uniones soldadas disímiles en barras de refuerzo para estructuras de concreto RESUMENEn este trabajo se ha investigado la influencia de utilizar Inconel 182 como material de “mantequillado” en las propiedades mecánicas de uniones disimiles acero al carbono-inoxidable manufacturadas por soldadura con electrodo recubierto. Para ello se han empleado las siguientes técnicas: análisis microestructural, ensayos de microdureza Vickers y ensayos mecánicos de tensión. Se ha empleado el proceso de soldadura con electrodo recubierto por que es el más común en la soldadura de campo para la construcción. Los resultados demuestran que aun cuando las uniones disimiles sin “mantequillado” presentan defectos, sus propiedades mecánicas son superiores a las de las uniones soldadas con “mantequillado”. Esta metodología es propuesta para la rehabilitación de estructuras de concreto para ambiente marino con barras de acero como refuerzos.Palabras clave: mantequillado; uniones soldadas con materiales disimiles; propiedades mecánicas; microestructura; defectos. Effect of buttering in mechanical properties of dissimilar metal weld joints for reinforcement bars in concrete structures ABSTRACTIn this work, the influence of Inconel 182 as buttering material in the mechanical properties of dissimilar metal welds between plain carbon steel and stainless steel bars welded using SMAW has been investigated using microstructural analysis, Vickers microhardness testing, and tensile tests. Welding with SMAW process is commonly applied in field welding of concrete structures; therefore this process was selected for this work. The results indicated that even if the joints contain defects generated by the welder, the mechanical properties of dissimilar welded joint without buttering are higher than the properties of joints with buttering. This methodology is proposed for the rehabilitation of concrete structures with steel bars as reinforcements, which are located in marine enviroments.  Keywords: buttering, dissimilar metal weld joints; mechanical properties; microstructure; defects. Efeito da introdução de um terceiro material sobre as propriedades mecânicas das juntas soldadas entre aço carbono e aço inox, em barras de aço para estruturas de concreto RESUMOEste artigo investiga a influência da utilização de Inconel 182 como um terceiro material, nas propriedades mecânicas de diferentes aços inoxidáveis soldados a aços carbono com uso de eletrodo revestido. Para tanto foram usados os seguintes métodos: análise microestrutural, ensaios de microdureza Vickers e ensaios mecânicos de tensão. Tem sido empregado o processo de solda com eletrodo revestido, porque é o mais comum no campo de solda para a construção. Os resultados mostram que quando as uniões são realizadas sem esse terceiro material, as propriedades mecânicas são superiores às das juntas soldadas com auxílio do Inconel 182. Esta metodologia, ora criticada, tem sido proposta para a reabilitação de estruturas de concreto em ambiente marinho, com uso de barras de aço inox como reforços.Palavras-chave: juntas soldadas com materiais diferentes; propriedades mecânicas; microestrutura; defeitos.

Study on the interfacial bonding behaviour of corroded steel bars and TRC constrained concrete

2019 ◽  
Vol 66 (5) ◽  
pp. 661-670
Author(s):  
Chang-Shun Hu ◽  
Shiping Yin ◽  
Meng-Ti Yin
Keyword(s):  
Bond Strength ◽  
Interfacial Bonding ◽  
Detectable Effect ◽  
Textile Reinforced Concrete ◽  
Content Type ◽  
Bonding Performance ◽  
Pull Out ◽  
Steel Bars ◽  
Bonding Properties ◽  
Ultimate Bond Strength

Purpose This paper aims to evaluate the bonding properties of textile reinforced concrete (TRC)-confined concrete and corroded plain round bars. Design/methodology/approach The bonding performance of three types of specimens (not reinforced, reinforced after corrosion and reinforced before corrosion) was studied by a central pull out test. Findings The ultimate bond strength between the corroded steel bars and the concrete is improved when the corrosion ratio is small. After cracking, the degree of corrosion continues to grow and the ultimate bond strength decreases. TRC reinforcement has no detectable effect on the interfacial bonding properties between concrete and plain round bars when the corrosion of steel bars is small; however, when the concrete cracks under the action of rust corrosion, the TRC constraints can effectively improve the bonding performance of the two components. Practical implications TRC layer significantly delayed the chloride penetration rate, which can effectively limit the development of corrosion cracking.

Mechanical and bond properties of new generation of carbon fibre reinforced polymer reinforcing bars for concrete structures

2002 ◽  
Vol 29 (2) ◽  
pp. 338-343 ◽  
Author(s):  
Brahim Benmokrane ◽  
Burong Zhang ◽  
Kader Laoubi ◽  
Brahim Tighiouart ◽  
Isabelle Lord
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Bond Strength ◽  
Concrete Structures ◽  
Reinforcing Bars ◽  
Reinforced Polymer ◽  
Steel Bars ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
New Generation

This paper presents laboratory test results on the mechanical properties and bond strength of new generation of carbon fibre reinforced polymer (CFRP) reinforcing bars used as nonprestressed reinforcement for concrete structures. Two types of CFRP reinforcing bars, namely, 9-mm-diameter CFRP ribbed bars and 9.5-mm-diameter CFRP sand-coated bars, were investigated. Tensile tests and pullout bond tests were conducted to evaluate the tensile properties and bond strength of the CFRP bars in comparison with that of the steel bar. Experimental results showed that the tensile stress-strain curves of the CFRP bars were linear up to failure. The ultimate tensile strength of the two types of CFRP bars was at least 1500 MPa, three times that of steel bars. The modulus of elasticity of two types of the CFRP bars was 128–145 GPa, about 65–75% that of steel. Furthermore, both types of the CFRP bars exhibited almost the same bond strength to concrete similar to steel bars. The minimum bond development length for the two types of CFRP bars seemed to be equal to about 20db for the sand-coated bars and 30db for the ribbed bars.Key words: fibre reinforced polymer (FRP), carbon FRP (CFRP), bar, mechanical properties, tensile strength, embedded length, pullout, bond strength, concrete structures.

The Impact of Corrosion on the Mechanical Properties of Smooth Steel Rebar HPB235

2011 ◽  
Vol 179-180 ◽  
pp. 28-31
Author(s):  
Xiao Yong Li ◽  
Zhi Gang Zhang
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Laboratory Tests ◽  
Structural Integrity ◽  
Strength Degradation ◽  
Progressive Reduction ◽  
Steel Rebar ◽  
Steel Bars ◽  
Before And After ◽  
The Impact

The Impact of Corrosion on the Mechanical Properties of Smooth Steel Rebar HPB235 The impact of corrosion on the mechanical properties of steel rebar was examined. An experimental investigation was carried out in order to gain better insight of the effect of corrosion on the mass loss, strength, of smooth Steel Rebar HPB235 10 mm diameter steel bars that were artificially corroded for different corrosion levels. Corrosion is a negative contributor on the structural integrity of concrete structures and leads to degradation of the mechanical properties of steel rebar. In order to evaluate the influence of corrosion on the mechanical properties of steel rebar, an experimental investigation was conducted on smooth steel rebar of 10 mm diameters, and which were artificially corroded for 1, 3, 5 and 7 months. The laboratory tests suggest that corrosion duration had a significant impact on the strength degradation of the specimens. The mechanical properties of tensile test before and after corrosion indicated progressive variation and drastic drop in their values. The corrosion enhanced the damage and created pits and notches, resulting in stress concentration points and progressive reduction of strength. It gets the express formula nominal ultimate strength and nominal yield strength.

scholarly journals Examination of Reinforcement Steel Bars Exposed to the Atmosphere

2020 ◽  
pp. 1-5
Author(s):  
Adejo O H ◽  
Keyword(s):  
Mechanical Properties ◽  
Sodium Chloride ◽  
Concrete Structures ◽  
The Other ◽  
Reinforced Concrete Structures ◽  
Reinforcement Steel ◽  
Corrosion Rates ◽  
Steel Bars ◽  
Steel Rebars ◽  
Strength And Ductility

Reinforcement steel bars are often exposed to the atmosphere before use in concrete structures. This exposure results in corrosion of these reinforcement bars. Corrosion of reinforcement bars is a common form of degradation of reinforced concrete structures. The electrochemical attack affects the mechanical properties of steel rebars. This study analysed the effect of exposing reinforcing steel bars to the atmosphere. The bars were divided into two; one part was exposed to the atmosphere for a period of four months during the rainy season while the other was unexposed. Afterwards; some mechanical, corrosion and metallographic tests were carried out on the steel samples. The results obtained showed that the hardness, impact strength and ductility increased with exposure while the yield and tensile strengths decreased with exposure. The exposed bar had high corrosion rates than the unexposed bar in 1M hydrochloric acid (HCl) while in 1M sodium chloride (NaCl), the corrosion rates for both the exposed and unexposed bars did not follow a particular trend.

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