The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Antonio Nanni - One of the best experts on this subject based on the ideXlab platform.
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Experimental bond behavior of hybrid rods for Concrete Reinforcement
Structural Engineering and Mechanics, 1997Co-Authors: Antonio Nanni, Jeremy S. Nenninger, Kenneth D. Ash, Judy LiuAbstract:Fiber reinforced plastic (FRP) rods provide certain benefits over steel as Concrete Reinforcement, such as corrosion resistance, magnetic and electrical insulation, light weight, and high strength. FRP composites can be combined with a steel core to form hybrid reinforcing rods that take advantage of properties of both materials. The objective of this study was to characterize the bond behavior of hybrid FRP rods made with braided epoxy-impregnated aramid or poly-vinyl alcohol FRP skins. Eleven rod types were tested using two Concrete strengths. Specific topics examined were bond strength, slip, and type of failure in concentric pull-out tests from Concrete cubes. From analysis of identical pull-out tests on both hybrid and steel rods, information on relative bond strength and behavior were obtained. It is concluded that strength is similar but slip in hybrid rods is much higher. Hybrid rods failed either by pull-out or splitting the Concrete block (with or without yielding of the steel core). Experimental data showed consistency with similar test results presented in the literature.
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tensile properties of hybrid rods for Concrete Reinforcement
Construction and Building Materials, 1994Co-Authors: Antonio Nanni, Markus J Henneke, Tadashi OkamotoAbstract:Abstract This paper presents an initial evaluation of hybrid Reinforcement for prestressed and non-prestressed Concrete members. A hybrid rod consists of an frp (Fibre-Reinforced-Plastic) skin with a steel core. The frp skin is made of braided, epoxy-impregnated aramid or vinylon fibre. Besides protecting the steel core from corrosion, the frp skin provides a structural function. Hybrid Reinforcement behaviour may be customized by changing the core-to-skin cross-section ratio and by combining different constituent materials. Tensile tests have shown that changing the frp skin material, frp skin thickness, steel core diameter, and steel core yield strength resulted in various stress-strain behaviours. The tensile stress-strain curves of the hybrid rods displayed a bilinear nature. It was demonstrated that the law of mixtures can be used to predict the stress-strain behaviour of the hybrid rods.
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tensile properties of braided frp rods for Concrete Reinforcement
Cement & Concrete Composites, 1993Co-Authors: Antonio Nanni, Tadashi Okamoto, Masaharu Tanigaki, Satoshi OsakadaAbstract:Abstract Fiber-reinforced-plastics (FRP) elements are being considered worldwide as an alternative type of Reinforcement for prestressed and non-prestressed Concrete structures. This paper reports on the static tensile properties of braided epoxy-impregnated FRP rods made with glass, aramid and polyvinyl alcohol fibers. As one of the FRP manufacturing methods — brading — has several advantages, one of which is the deformed external rod-surface for improved bond with Concrete. The research program was aimed to determine stress-strain curve shape, elastic modulus, Poisson's ratio, ultimate strength and ultimate elongation for three rod diameters. The apparent Poisson's ratio was measured with two independent methods (strain gages and rod volume change by water displacement). It was found that, for practical purposes, braided FRP rods can be considered linear elastic. Ultimate strength and rigidity are approximately 80% of that derived on the basis of the constituent material properties (when fivers ultimate elongation is smaller than that of the resin). Poisson's ratio and ultimate strength can be affected by rod size.
Tadashi Okamoto - One of the best experts on this subject based on the ideXlab platform.
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tensile properties of hybrid rods for Concrete Reinforcement
Construction and Building Materials, 1994Co-Authors: Antonio Nanni, Markus J Henneke, Tadashi OkamotoAbstract:Abstract This paper presents an initial evaluation of hybrid Reinforcement for prestressed and non-prestressed Concrete members. A hybrid rod consists of an frp (Fibre-Reinforced-Plastic) skin with a steel core. The frp skin is made of braided, epoxy-impregnated aramid or vinylon fibre. Besides protecting the steel core from corrosion, the frp skin provides a structural function. Hybrid Reinforcement behaviour may be customized by changing the core-to-skin cross-section ratio and by combining different constituent materials. Tensile tests have shown that changing the frp skin material, frp skin thickness, steel core diameter, and steel core yield strength resulted in various stress-strain behaviours. The tensile stress-strain curves of the hybrid rods displayed a bilinear nature. It was demonstrated that the law of mixtures can be used to predict the stress-strain behaviour of the hybrid rods.
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tensile properties of braided frp rods for Concrete Reinforcement
Cement & Concrete Composites, 1993Co-Authors: Antonio Nanni, Tadashi Okamoto, Masaharu Tanigaki, Satoshi OsakadaAbstract:Abstract Fiber-reinforced-plastics (FRP) elements are being considered worldwide as an alternative type of Reinforcement for prestressed and non-prestressed Concrete structures. This paper reports on the static tensile properties of braided epoxy-impregnated FRP rods made with glass, aramid and polyvinyl alcohol fibers. As one of the FRP manufacturing methods — brading — has several advantages, one of which is the deformed external rod-surface for improved bond with Concrete. The research program was aimed to determine stress-strain curve shape, elastic modulus, Poisson's ratio, ultimate strength and ultimate elongation for three rod diameters. The apparent Poisson's ratio was measured with two independent methods (strain gages and rod volume change by water displacement). It was found that, for practical purposes, braided FRP rods can be considered linear elastic. Ultimate strength and rigidity are approximately 80% of that derived on the basis of the constituent material properties (when fivers ultimate elongation is smaller than that of the resin). Poisson's ratio and ultimate strength can be affected by rod size.
Johannes Portielje Rauff Greisen - One of the best experts on this subject based on the ideXlab platform.
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scrim sparse Concrete Reinforcement in meshworks
Robotic Fabrication in Architecture Art and Design, 2018Co-Authors: Phil Ayres, Paul Nicholas, Thomas Juul Andersen, Wilson Ricardo Leal Da Silva, Johannes Portielje Rauff GreisenAbstract:This paper introduces a novel hybrid construction concept, namely Sparse Concrete Reinforcement In Meshworks (SCRIM), that intersects robot-based 3D Concrete Printing (3DCP) and textile Reinforcement meshes to produce lightweight elements. In contrast to existing 3DCP approaches, which often stack material vertically, the SCRIM approach permits full exploitation of 6-axis robotic control by utilising supportive meshes to define 3D surfaces onto which Concrete is selectively deposited at various orientation angles. Also, instead of fully encapsulating the textile in a cementitious matrix using formworks or spraying Concrete, SCRIM relies on sparsely depositing Concrete to achieve structural, tectonic and aesthetic design goals, minimising material use. The motivation behind this novel concept is to fully engage the 3D control capabilities of conventional robotics in Concrete use, offering an enriched spatial potential extending beyond extruded geometries prevalent in 3DCP, and diversifying the existing spectrum of digital construction approaches. The SCRIM concept is demonstrated through a small-scale proof-of-concept and a larger-scale experiment, described in this paper. Based on the results, we draw a critical review on the limitations and potentials of the approach.
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SCRIM – Sparse Concrete Reinforcement in Meshworks
Robotic Fabrication in Architecture Art and Design 2018, 2018Co-Authors: Phil Ayres, Paul Nicholas, Thomas Juul Andersen, Wilson Ricardo Leal Da Silva, Johannes Portielje Rauff GreisenAbstract:This paper introduces a novel hybrid construction concept, namely Sparse Concrete Reinforcement In Meshworks (SCRIM), that intersects robot-based 3D Concrete Printing (3DCP) and textile Reinforcement meshes to produce lightweight elements. In contrast to existing 3DCP approaches, which often stack material vertically, the SCRIM approach permits full exploitation of 6-axis robotic control by utilising supportive meshes to define 3D surfaces onto which Concrete is selectively deposited at various orientation angles. Also, instead of fully encapsulating the textile in a cementitious matrix using formworks or spraying Concrete, SCRIM relies on sparsely depositing Concrete to achieve structural, tectonic and aesthetic design goals, minimising material use. The motivation behind this novel concept is to fully engage the 3D control capabilities of conventional robotics in Concrete use, offering an enriched spatial potential extending beyond extruded geometries prevalent in 3DCP, and diversifying the existing spectrum of digital construction approaches. The SCRIM concept is demonstrated through a small-scale proof-of-concept and a larger-scale experiment, described in this paper. Based on the results, we draw a critical review on the limitations and potentials of the approach.
Raúl Fangueiro - One of the best experts on this subject based on the ideXlab platform.
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Hybrid composite rods for Concrete Reinforcement
2010Co-Authors: Raúl Fangueiro, Said Jalali, Mário Duarte De Araújo, Cristiana Gonilho Pereira, P. MarquesAbstract:The Concrete construction industry deals every day with the deterioration of Concrete structures. Nowadays a large number of bridges, buildings and other structural elements require rehabilitation and repair and its maintenance have become an increasingly serious problem. Concrete structures when subjected to repeated loading and to aggressive environmental agents present a decrease in terms of mechanical properties and durability performance. Corrosion of steel is one of the most serious problems of Concrete structures. Several techniques have been developed to reduce corrosion of steel but none seems to be a suitable solution for the corrosion problem. Therefore, the use of fibre reinforced composite rods as Concrete Reinforcement material seems to be an effective solution to overcome durability problems of traditional steel reinforced Concrete structures. The main advantages of fibre reinforced composite materials over steel include the excellent corrosive resistance, mechanical properties similar to steel, high strength-to-weight ratio and excellent fatigue resistance, among others. Thus, the replacement of steel rebars with fibre reinforced composite rods is gaining popularity worldwide. The Concrete construction industry deals every day with the deterioration of steel reinforced Concrete structures. Concrete structures when subjected to repeated loading and to aggressive environmental agents present a decrease in terms of mechanical properties and durability performance. Corrosion of steel is one of the most serious problems of Concrete structures. Deterioration of Concrete severely affects the service life, safety and maintenance costs of Concrete structures. Moreover, reinforced and pre-stressed Concrete structures are particularly vulnerable, especially those exposed to moist and aggressive environments. In this case, steel corrodes producing unsightly staining, cracking and spalling of the Concrete due to the volume expansion of the iron as the oxide is formed. Stainless steel, galvanizing, epoxy coating and other procedures are some of the techniques that have been developed to reduce steel corrosion, but none of the solutions seem to be viable as suitable solution to eliminate the corrosion problem. Therefore, fibre reinforced composite materials have recently received a great deal of attention by the civil engineering scientific community (Chaallal, 1996) (Micelli, 2004). The advantages of fibre reinforced composite ma
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Braided composite rods to reinforce Concrete subjected to aggressive environments
2008Co-Authors: Cristiana Gonilho Pereira, Raúl Fangueiro, Said Jalali, P. Marques, Mário Duarte De AraújoAbstract:Fundacao para a Ciencia e a Tecnologia (FCT) - projecto POCI/CTM/6086/2004, “Development of braided reinforced composite elements for Concrete Reinforcement and monitoring”.
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Composite rods as a steel substitute in Concrete Reinforcement
2007Co-Authors: C. Gonilho Pereira, Raúl Fangueiro, Said Jalali, Mário Duarte De Araújo, P. MarquesAbstract:The current work is concerning with the development of braided reinforced composites rods for Concrete Reinforcement, as a steel substitute. The research study aims to understand the mechanical behaviour of composite rods reinforced by a fibrous structure – core reinforced braided fabric. Several samples of braided reinforced composite rods were produced. Polyester fibres were used to produce the braided fabric; several types of fibres, and several combinations of fibres, were used as braided fabric core Reinforcement; and polyester resin was used as polymeric matrix. The mechanical properties of braided reinforced composite rods have been evaluated under tensile. The objective was to identify the type of fibre, or combination of fibres, to be used as braided fabric core Reinforcement, in order to produce composite rods with mechanical properties similar to those of steel rebars.
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Application of Braided Fibre Reinforced Composite Rods in Concrete Reinforcement
Materials Science Forum, 2006Co-Authors: Raúl Fangueiro, Said Jalali, Gisele Ferreira De Sousa, F. Soutinho, M. De AraújoAbstract:This paper describes the work that is being done at the University of Minho concerning the development of braided rods for Concrete Reinforcement. A preliminary research study has been conducted to understand the mechanical behaviour of braided fabrics. Various samples have been produced varying the type of fiber (glass, polyester and aramid), the type of braided fabric (simple, hybrid and core reinforced) and in the latter case, the number of core reinforcing yarns. The tensile properties of these samples have been evaluated and the results presented. The influence of each factor on the tensile properties of braided fabrics has also been analysed and discussed. In order to produce braided reinforced composite rods to use as a Concrete Reinforcement, a special technique has been developed using a standard vertical braiding machine. The braided reinforced composite materials have been produced in rib structure to improve adhesion between them and the Concrete. Special samples have been prepared and tested to evaluate the adherence between both materials involved. The tensile and bending properties of braided reinforced composite rods have been evaluated and the results obtained presented and discussed.
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Braided fibre reinforced composite rods for Concrete Reinforcement
2005Co-Authors: Raúl Fangueiro, Guilherme José Miranda De Sousa, Hélder Filipe Cunha Soutinho, Said Jalali, Mário Duarte De AraújoAbstract:This paper describes the work that is being done at the University of Minho concerning the development of braided rods for Concrete Reinforcement. A preliminary research study has been conducted to understand the mechanical behaviour of braided fabrics. Various samples have been produced varying the type of fiber (glass, polyester and aramid), the type of braided fabric (simple, hybrid and core reinforced) and in the latter case, the number of core reinforcing yarns. The tensile properties of these samples have been evaluated and the results presented. The influence of each factor on the tensile properties of braided fabrics has also been analysed and discussed. In order to produce braided reinforced composite rods to use as a Concrete Reinforcement, a special technique has been developed using a standard vertical braiding machine. The braided reinforced composite materials have been produced in a ribbed structure to improve adhesion between them and the Concrete. Special samples have been prepared and tested to evaluate the adherence between both materials involved. The tensile and bending properties of braided reinforced composite rods have been evaluated and the results obtained presented and discussed.
Mário Duarte De Araújo - One of the best experts on this subject based on the ideXlab platform.
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Hybrid composite rods for Concrete Reinforcement
2010Co-Authors: Raúl Fangueiro, Said Jalali, Mário Duarte De Araújo, Cristiana Gonilho Pereira, P. MarquesAbstract:The Concrete construction industry deals every day with the deterioration of Concrete structures. Nowadays a large number of bridges, buildings and other structural elements require rehabilitation and repair and its maintenance have become an increasingly serious problem. Concrete structures when subjected to repeated loading and to aggressive environmental agents present a decrease in terms of mechanical properties and durability performance. Corrosion of steel is one of the most serious problems of Concrete structures. Several techniques have been developed to reduce corrosion of steel but none seems to be a suitable solution for the corrosion problem. Therefore, the use of fibre reinforced composite rods as Concrete Reinforcement material seems to be an effective solution to overcome durability problems of traditional steel reinforced Concrete structures. The main advantages of fibre reinforced composite materials over steel include the excellent corrosive resistance, mechanical properties similar to steel, high strength-to-weight ratio and excellent fatigue resistance, among others. Thus, the replacement of steel rebars with fibre reinforced composite rods is gaining popularity worldwide. The Concrete construction industry deals every day with the deterioration of steel reinforced Concrete structures. Concrete structures when subjected to repeated loading and to aggressive environmental agents present a decrease in terms of mechanical properties and durability performance. Corrosion of steel is one of the most serious problems of Concrete structures. Deterioration of Concrete severely affects the service life, safety and maintenance costs of Concrete structures. Moreover, reinforced and pre-stressed Concrete structures are particularly vulnerable, especially those exposed to moist and aggressive environments. In this case, steel corrodes producing unsightly staining, cracking and spalling of the Concrete due to the volume expansion of the iron as the oxide is formed. Stainless steel, galvanizing, epoxy coating and other procedures are some of the techniques that have been developed to reduce steel corrosion, but none of the solutions seem to be viable as suitable solution to eliminate the corrosion problem. Therefore, fibre reinforced composite materials have recently received a great deal of attention by the civil engineering scientific community (Chaallal, 1996) (Micelli, 2004). The advantages of fibre reinforced composite ma
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Braided composite rods to reinforce Concrete subjected to aggressive environments
2008Co-Authors: Cristiana Gonilho Pereira, Raúl Fangueiro, Said Jalali, P. Marques, Mário Duarte De AraújoAbstract:Fundacao para a Ciencia e a Tecnologia (FCT) - projecto POCI/CTM/6086/2004, “Development of braided reinforced composite elements for Concrete Reinforcement and monitoring”.
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Composite rods as a steel substitute in Concrete Reinforcement
2007Co-Authors: C. Gonilho Pereira, Raúl Fangueiro, Said Jalali, Mário Duarte De Araújo, P. MarquesAbstract:The current work is concerning with the development of braided reinforced composites rods for Concrete Reinforcement, as a steel substitute. The research study aims to understand the mechanical behaviour of composite rods reinforced by a fibrous structure – core reinforced braided fabric. Several samples of braided reinforced composite rods were produced. Polyester fibres were used to produce the braided fabric; several types of fibres, and several combinations of fibres, were used as braided fabric core Reinforcement; and polyester resin was used as polymeric matrix. The mechanical properties of braided reinforced composite rods have been evaluated under tensile. The objective was to identify the type of fibre, or combination of fibres, to be used as braided fabric core Reinforcement, in order to produce composite rods with mechanical properties similar to those of steel rebars.
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Braided fibre reinforced composite rods for Concrete Reinforcement
2005Co-Authors: Raúl Fangueiro, Guilherme José Miranda De Sousa, Hélder Filipe Cunha Soutinho, Said Jalali, Mário Duarte De AraújoAbstract:This paper describes the work that is being done at the University of Minho concerning the development of braided rods for Concrete Reinforcement. A preliminary research study has been conducted to understand the mechanical behaviour of braided fabrics. Various samples have been produced varying the type of fiber (glass, polyester and aramid), the type of braided fabric (simple, hybrid and core reinforced) and in the latter case, the number of core reinforcing yarns. The tensile properties of these samples have been evaluated and the results presented. The influence of each factor on the tensile properties of braided fabrics has also been analysed and discussed. In order to produce braided reinforced composite rods to use as a Concrete Reinforcement, a special technique has been developed using a standard vertical braiding machine. The braided reinforced composite materials have been produced in a ribbed structure to improve adhesion between them and the Concrete. Special samples have been prepared and tested to evaluate the adherence between both materials involved. The tensile and bending properties of braided reinforced composite rods have been evaluated and the results obtained presented and discussed.