Characteristics of basalt fiber as a strengthening material for concrete structures
JongsungSimCheolwooParkDo YoungMoon
LinkCharacteristics of basalt fiber as a strengthening material for concrete structures - ScienceDirect Abstract This study investigates the applicability of the basalt fiber as a strengthening material for structural concrete members through various experimental works for durability, mechanical properties, and flexural strengthening. The basalt fiber used in this study was manufactured in Russia and exhibited the tensile strength of 1000 MPa, which was about 30% of the carbon and 60% of the high strength glass (S-glass) fiber. When the fibers were immersed into an alkali solution, the basalt and glass fibers lost their volumes and strengths with a reaction product on the surface but the carbon fiber did not show significant strength reduction. From the accelerated weathering test, the basalt fiber was found to provide better resistance than the glass fiber. However, the basalt fiber kept about 90% of the normal temperature strength after exposure at 600 °C for 2 h whereas the carbon and the glass fibers did not maintain their volumetric integrity. In the tests for flexural strengthening evaluation, the basalt fiber strengthening improved both the yielding and the ultimate strength of the beam specimen up to 27% depending on the number of layers applied. From the results presented herein, two layers of the basalt fiber sheets were thought to be better strengthening scheme. In addition, the strengthening does not need to extend over the entire length of the flexural member. When moderate structural strengthening but high resistance for fire is simultaneously sought such as for building structures, the basalt fiber strengthening will be a good alternative methodology among other fiber reinforced polymer (FRP) strengthening systems. Introduction For the strengthening of deteriorated reinforced concrete structural members, fiber reinforced polymer (FRP) strengthening system has emerged as an alternative to traditional techniques using a steel plate. These FRP materials include carbon, glass and aramid FRPs and provide advantages over the traditional repair materials in terms of better mechanical and chemical performance and easier constructability [1], [2], [3]. It is true, however, that despite of its high ultimate strength, structures strengthened with FRPs can be failed in a brittle manner potentially below its mechanical capacity due to a bonding problem at the strengthening material–concrete interface. This safety concern is more significant when the carbon FRP materials are used [4], [5]. Hence, it was suggested to use a greater safety factor for the ultimate strength or to establish a limit state of ultimate load carrying capacity for the concrete structures strengthened with carbon FRP [6]. On the other hand, as the use of the FRP materials becomes extended to rehabilitation or strengthening of building structures, fire resistance is another important aspect of the materials. When exposed to a high-temperature, most of FRP materials lose structural capacity rapidly. Particularly, an organic epoxy resin, which is added as a matrix or additive during production or shaping process, can make very dangerous poisonous fumes [7]. Therefore, for the strengthening of reinforced concrete structures, a material is sought which has larger ultimate strain even at the some sacrifice of strength and greater fire resistance at the same time. Basalt fibers are from basalt rocks through melting process. The basalt rocks can be so finely divided into small particles that it is possible to produce into a form of fibers. In addition, the basalt fibers do not contain any other additives in a single producing process, which makes additional advantage in cost. It is known that the basalt fibers have better tensile strength than the E-glass fibers, greater failure strain than the carbon fibers as well as good resistance to chemical attack, impact load and fire with less poisonous fumes [8]. From these advantages, the applicability of the basalt fiber for a structural strengthening material is highly expected. The study of Brik [9], [10] already investigated fundamental properties of the basalt fiber as a reinforcing steel replacement in the concrete structures. There are two typical types of the FRP strengthening methods such as external bonding and near surface mounting methods, which use a sheet or layer material, and a rod type material, respectively. The rod type FRP materials can be used as a replacement of the traditional reinforcing steel. In addition, recent researches attempt to use only fibers with no resin matrix for shear strengthening replacing stirrups [11]. In order for those FRP materials to be used as a strengthening material, it might be necessary to investigate the mechanical and durability issues simultaneously. This study investigates the mechanical property and the durability of the basalt fiber and evaluates flexural strengthening performance for reinforce concrete beams. Throughout the experimental studies presented herein, the results may provide fundamental information for the application of the basalt fibers as a strengthening material. The basalt fiber used herein was produced in Russia where conserves a sufficient amount of the basalt resource. Section snippets Mechanical property of basalt fiber The basalt fiber used had a density of 2.593 g/cm3 and a diameter of 10.6 μm measured by SEM. Following a modified ISO 11566, Determination of the Tensile Properties of Single-filament Specimens, tensile strength, elasticity modulus and elongation at failure were measured and the results are listed in Table 1. A piece of basalt fiber string was fixed at the center of a cardboard which had a 20 mm long hollow section in the middle. Using a 5 N capacity actuator, tensile load was applied on theFlexural strengthening of beam with basalt fiber sheet This chapter evaluates the applicability of the basalt fiber as a flexure strengthening material for reinforced concrete beam members. In this study, the basalt fiber sheets were bonded on the surface of the beam specimens and the flexure strengthened specimens were tested under a four-point bending configuration (Table 2). Conlusions In the study herein, the applicability of the basalt fiber as a strengthening material was investigated through various experimental works for durability, mechanical characteristics and strengthening effects. The basalt fiber manufactured in Russia exhibited the tensile strength less than 1000 MPa, which was about 30% of the carbon and 60% of the high strength glass (S-glass) fiber. When those three different fibers were immersed into an alkali solution, the basalt and the glass fibers lost References (13) • S. Yilmaz et al.Crystallization kinetics of basalt glass
Ceram Int(1996)• G.S. Kim et al.Premature failure behavior of RC beams strengthened by platesJ Korean Soc Civil Eng(1999)• Sim J. Static and dynamics analysis of strengthening effect of glass FRP for bridge deck plate. Tech Res Report...• Sim J. Static and dynamics analysis of strengthening effect of carbon fiber sheet for concrete structure. Tech Res...• Y.T. Lee et al.Performance of concrete structures retrofitted with fiber reinforce polymersMag Korean Conc Inst(2002)• G.H. Hong et al.Structural performance evaluation of reinforced concrete beams with externally bonded FRP sheetsJ Korean Conc Inst(2003)
LinkCharacteristics of basalt fiber as a strengthening material for concrete structures - ScienceDirect Abstract This study investigates the applicability of the basalt fiber as a strengthening material for structural concrete members through various experimental works for durability, mechanical properties, and flexural strengthening. The basalt fiber used in this study was manufactured in Russia and exhibited the tensile strength of 1000 MPa, which was about 30% of the carbon and 60% of the high strength glass (S-glass) fiber. When the fibers were immersed into an alkali solution, the basalt and glass fibers lost their volumes and strengths with a reaction product on the surface but the carbon fiber did not show significant strength reduction. From the accelerated weathering test, the basalt fiber was found to provide better resistance than the glass fiber. However, the basalt fiber kept about 90% of the normal temperature strength after exposure at 600 °C for 2 h whereas the carbon and the glass fibers did not maintain their volumetric integrity. In the tests for flexural strengthening evaluation, the basalt fiber strengthening improved both the yielding and the ultimate strength of the beam specimen up to 27% depending on the number of layers applied. From the results presented herein, two layers of the basalt fiber sheets were thought to be better strengthening scheme. In addition, the strengthening does not need to extend over the entire length of the flexural member. When moderate structural strengthening but high resistance for fire is simultaneously sought such as for building structures, the basalt fiber strengthening will be a good alternative methodology among other fiber reinforced polymer (FRP) strengthening systems. Introduction For the strengthening of deteriorated reinforced concrete structural members, fiber reinforced polymer (FRP) strengthening system has emerged as an alternative to traditional techniques using a steel plate. These FRP materials include carbon, glass and aramid FRPs and provide advantages over the traditional repair materials in terms of better mechanical and chemical performance and easier constructability [1], [2], [3]. It is true, however, that despite of its high ultimate strength, structures strengthened with FRPs can be failed in a brittle manner potentially below its mechanical capacity due to a bonding problem at the strengthening material–concrete interface. This safety concern is more significant when the carbon FRP materials are used [4], [5]. Hence, it was suggested to use a greater safety factor for the ultimate strength or to establish a limit state of ultimate load carrying capacity for the concrete structures strengthened with carbon FRP [6]. On the other hand, as the use of the FRP materials becomes extended to rehabilitation or strengthening of building structures, fire resistance is another important aspect of the materials. When exposed to a high-temperature, most of FRP materials lose structural capacity rapidly. Particularly, an organic epoxy resin, which is added as a matrix or additive during production or shaping process, can make very dangerous poisonous fumes [7]. Therefore, for the strengthening of reinforced concrete structures, a material is sought which has larger ultimate strain even at the some sacrifice of strength and greater fire resistance at the same time. Basalt fibers are from basalt rocks through melting process. The basalt rocks can be so finely divided into small particles that it is possible to produce into a form of fibers. In addition, the basalt fibers do not contain any other additives in a single producing process, which makes additional advantage in cost. It is known that the basalt fibers have better tensile strength than the E-glass fibers, greater failure strain than the carbon fibers as well as good resistance to chemical attack, impact load and fire with less poisonous fumes [8]. From these advantages, the applicability of the basalt fiber for a structural strengthening material is highly expected. The study of Brik [9], [10] already investigated fundamental properties of the basalt fiber as a reinforcing steel replacement in the concrete structures. There are two typical types of the FRP strengthening methods such as external bonding and near surface mounting methods, which use a sheet or layer material, and a rod type material, respectively. The rod type FRP materials can be used as a replacement of the traditional reinforcing steel. In addition, recent researches attempt to use only fibers with no resin matrix for shear strengthening replacing stirrups [11]. In order for those FRP materials to be used as a strengthening material, it might be necessary to investigate the mechanical and durability issues simultaneously. This study investigates the mechanical property and the durability of the basalt fiber and evaluates flexural strengthening performance for reinforce concrete beams. Throughout the experimental studies presented herein, the results may provide fundamental information for the application of the basalt fibers as a strengthening material. The basalt fiber used herein was produced in Russia where conserves a sufficient amount of the basalt resource. Section snippets Mechanical property of basalt fiber The basalt fiber used had a density of 2.593 g/cm3 and a diameter of 10.6 μm measured by SEM. Following a modified ISO 11566, Determination of the Tensile Properties of Single-filament Specimens, tensile strength, elasticity modulus and elongation at failure were measured and the results are listed in Table 1. A piece of basalt fiber string was fixed at the center of a cardboard which had a 20 mm long hollow section in the middle. Using a 5 N capacity actuator, tensile load was applied on theFlexural strengthening of beam with basalt fiber sheet This chapter evaluates the applicability of the basalt fiber as a flexure strengthening material for reinforced concrete beam members. In this study, the basalt fiber sheets were bonded on the surface of the beam specimens and the flexure strengthened specimens were tested under a four-point bending configuration (Table 2). Conlusions In the study herein, the applicability of the basalt fiber as a strengthening material was investigated through various experimental works for durability, mechanical characteristics and strengthening effects. The basalt fiber manufactured in Russia exhibited the tensile strength less than 1000 MPa, which was about 30% of the carbon and 60% of the high strength glass (S-glass) fiber. When those three different fibers were immersed into an alkali solution, the basalt and the glass fibers lost References (13) • S. Yilmaz et al.Crystallization kinetics of basalt glass
Ceram Int(1996)• G.S. Kim et al.Premature failure behavior of RC beams strengthened by platesJ Korean Soc Civil Eng(1999)• Sim J. Static and dynamics analysis of strengthening effect of glass FRP for bridge deck plate. Tech Res Report...• Sim J. Static and dynamics analysis of strengthening effect of carbon fiber sheet for concrete structure. Tech Res...• Y.T. Lee et al.Performance of concrete structures retrofitted with fiber reinforce polymersMag Korean Conc Inst(2002)• G.H. Hong et al.Structural performance evaluation of reinforced concrete beams with externally bonded FRP sheetsJ Korean Conc Inst(2003)