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J M L Reis - One of the best experts on this subject based on the ideXlab platform.
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effect of aging on the fracture mechanics of unsaturated polyester based on recycled pet Polymer Concrete
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2011Co-Authors: J M L ReisAbstract:Abstract This research investigates, the fracture mechanics (toughness and energy), at early ages, of Polymer Concrete made with unsaturated polyester resin as binder. The results indicate that the fracture parameters (toughness and energy) decrease and the brittleness increases with the age of the Polymer Concrete.
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effect of textile waste on the mechanical properties of Polymer Concrete
Materials Research-ibero-american Journal of Materials, 2009Co-Authors: J M L ReisAbstract:The mechanical behavior of Polymer Concrete reinforced with textile trimming waste was investigated. Two series of Polymer Concrete formulations were studied, with different resin/sand (i.e. binder/fine aggregate) weight ratios. In each series, recycled textile chopped fibers at 1 and 2% of the total weight was used. Flexural and compressive tests were performed at room temperature and load vs. displacement curves were plotted up to failure. In the study, both the influence of fiber content and resin/sand weight ratio were considered relative to the behavior of Polymer Concrete reinforced with textile fibers. A decrease in properties was observed as function of textile fibers content. When specific properties were considered, this tendency was kept. However, higher textile fibers content lead to a smoother failure, unlike brittleness failure behavior of unreinforced Polymer Concrete.
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freeze thaw and thermal degradation influence on the fracture properties of carbon and glass fiber reinforced Polymer Concrete
Construction and Building Materials, 2006Co-Authors: J M L Reis, A. J. M. FerreiraAbstract:Abstract In recent years, it has been found that some Concrete structures, even for some high performance Concrete and ready mixed Concrete under good quality control, start to deteriorate long before reaching their designed service life. Cracks are found after the structure has been completed for a few years, which results in the shortening of service life and lowering in durability. In this paper, the influence on the fracture properties of fiber reinforced Polymer Concrete, FRPC, subjected to freeze–thaw and thermal degradation, is discussed. The study on the damage influence was conducted using a climate chamber to perform the temperature changes on the single edge notched beams. FRPC specimens were subjected to freeze–thaw and higher temperature cycles and then tested according to RILEM standards. To determine the stress intensity factor, K Ic , critical crack tip opening displacement CTODc, the Two Parameter Method was used and the fracture energy, G f of the specimens was calculated to evaluate the fracture properties of FRPC. Three-point bending tests were carried out on notched beams with a clip gauge attached to measure the crack mouth opening displacement CMOD. Polymer Concrete was reinforced with short glass and carbon fiber with 1% and 2% in mass respectively, to determine whether the reinforcement increases the performance of the material. The fracture properties of FRPC are reported in such conditions.
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fracture and flexural characterization of natural fiber reinforced Polymer Concrete
Construction and Building Materials, 2006Co-Authors: J M L ReisAbstract:Abstract Mechanical characterization of epoxy Polymer Concrete reinforced with natural fibers is investigated in this work to analyze the possibility of substitution by synthetic fibers. These natural fibers studied are coconut, sugar cane bagasse, and banana fibers. All of these fibers come from their specific products after they have been used, i.e. as recycle. As the natural fibers are agriculture waste, manufacturing natural product is, therefore, an economic and interesting option. The main idea is to use the fibers like they come from nature without any kind of preparation. The comparison between epoxy Polymer Concrete reinforced with natural fibers, unreinforced and reinforced with synthetic fibers is made. A brief description of how the natural fibers are obtained and manufacturing process of Polymer Concrete is also made.
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Assessment of fracture properties of epoxy Polymer Concrete reinforced with short carbon and glass fibers
Construction and Building Materials, 2004Co-Authors: J M L Reis, A. J. M. FerreiraAbstract:Polymer Concrete is a composite material formed by Polymerizing a monomer and aggregate mixture. The Polymerized monomer acts as the aggregates binder. In this research work, the Polymer is epoxy resin and the aggregate is a silica sand as used in the foundry industry. Initiators and promoters are added to the resin prior to its mixing with the inorganic aggregates to initiate the curing reaction. Fracture behavior of chopped carbon and glass fibers reinforced epoxy Polymer Concrete was investigated in this study using the two parameter model, according to RILEM recommendations. This is a direct method to calculate two size independent fracture parameters, i.e., the critical stress intensity factor, KIC, and the crack tip opening displacement (CTOD). Beams with central notch, under three point bending using attached clip gauge to measure the CTOD were tested. The chopped carbon and glass fibers used were 6 mm long. The glass fibers were also pre-treated with Silane to improve the adhesion between fibers and resin and fracture properties. In general, addition of fibers increases flexural strength and fracture properties. The fracture toughness of carbon fiber reinforced Polymer Concrete can increase up to 29% while glass fiber Polymer Concrete can increase up to 13% when comparing with epoxy non reinforced Polymer Concrete. The object of this research work is to evaluate the influence of fibers in the mechanical and fracture properties of Polymer Concrete.
A. J. M. Ferreira - One of the best experts on this subject based on the ideXlab platform.
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freeze thaw and thermal degradation influence on the fracture properties of carbon and glass fiber reinforced Polymer Concrete
Construction and Building Materials, 2006Co-Authors: J M L Reis, A. J. M. FerreiraAbstract:Abstract In recent years, it has been found that some Concrete structures, even for some high performance Concrete and ready mixed Concrete under good quality control, start to deteriorate long before reaching their designed service life. Cracks are found after the structure has been completed for a few years, which results in the shortening of service life and lowering in durability. In this paper, the influence on the fracture properties of fiber reinforced Polymer Concrete, FRPC, subjected to freeze–thaw and thermal degradation, is discussed. The study on the damage influence was conducted using a climate chamber to perform the temperature changes on the single edge notched beams. FRPC specimens were subjected to freeze–thaw and higher temperature cycles and then tested according to RILEM standards. To determine the stress intensity factor, K Ic , critical crack tip opening displacement CTODc, the Two Parameter Method was used and the fracture energy, G f of the specimens was calculated to evaluate the fracture properties of FRPC. Three-point bending tests were carried out on notched beams with a clip gauge attached to measure the crack mouth opening displacement CMOD. Polymer Concrete was reinforced with short glass and carbon fiber with 1% and 2% in mass respectively, to determine whether the reinforcement increases the performance of the material. The fracture properties of FRPC are reported in such conditions.
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reinforced Polymer Concrete physical properties of the matrix and static dynamic bond behaviour
Cement & Concrete Composites, 2005Co-Authors: Tomas J Sanjose, Iñigo Vegas, A. J. M. FerreiraAbstract:Abstract The paper aims at analysing the performance of Polyester Polymer Concrete (PPC) reinforced with steel and FRP rebars. The PPC is also compared with conventional cement Concrete. On the one hand, the effect of the Polymer matrix microstructure on the mechanical performance (compression and flexural strength, deformability and Young’s modulus) is discussed. On the other hand, static and dynamic bond behaviour under pure pull-out forces between the PPC and different rebars is tackled. It is analysed the behaviour of metallic and non-metallic rebars embedded in a PPC matrix when they are subjected to both monotonic and cyclic loads. Likewise, analogous tests were performed on cement Concrete specimens in order to be able to compare the bonding performance in both types of Concrete.
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Assessment of fracture properties of epoxy Polymer Concrete reinforced with short carbon and glass fibers
Construction and Building Materials, 2004Co-Authors: J M L Reis, A. J. M. FerreiraAbstract:Polymer Concrete is a composite material formed by Polymerizing a monomer and aggregate mixture. The Polymerized monomer acts as the aggregates binder. In this research work, the Polymer is epoxy resin and the aggregate is a silica sand as used in the foundry industry. Initiators and promoters are added to the resin prior to its mixing with the inorganic aggregates to initiate the curing reaction. Fracture behavior of chopped carbon and glass fibers reinforced epoxy Polymer Concrete was investigated in this study using the two parameter model, according to RILEM recommendations. This is a direct method to calculate two size independent fracture parameters, i.e., the critical stress intensity factor, KIC, and the crack tip opening displacement (CTOD). Beams with central notch, under three point bending using attached clip gauge to measure the CTOD were tested. The chopped carbon and glass fibers used were 6 mm long. The glass fibers were also pre-treated with Silane to improve the adhesion between fibers and resin and fracture properties. In general, addition of fibers increases flexural strength and fracture properties. The fracture toughness of carbon fiber reinforced Polymer Concrete can increase up to 29% while glass fiber Polymer Concrete can increase up to 13% when comparing with epoxy non reinforced Polymer Concrete. The object of this research work is to evaluate the influence of fibers in the mechanical and fracture properties of Polymer Concrete.
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chemical resistance of epoxy and polyester Polymer Concrete to acids and salts
Journal of Polymer Engineering, 2002Co-Authors: M. C. S. Ribeiro, C M L Tavares, A. J. M. FerreiraAbstract:The aim of this work is to analyse the chemical resistance of epoxy and polyester Concretes when exposed to acids and salts. The chemical resistance is evaluated through the variation of bending strength and variation of mass, after exposure in acid and salted solutions, for various periods of time. Aqueous solutions of sulphuric acid and sodium chloride were chosen as test solutions. The increasing use of Polymer Concrete structures near seawater and residual waters is the main motivation for this research work.
Kyungchae Jung - One of the best experts on this subject based on the ideXlab platform.
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thermal behavior and performance evaluation of epoxy based Polymer Concretes containing silicone rubber for use as runway repair materials
Composite Structures, 2015Co-Authors: Kyungchae Jung, Intaek Roh, Seunghwa ChangAbstract:Abstract This paper investigates the applicability of a Polymer Concrete as a repair material for runways by evaluating the differences in its thermal behaviors and mechanical properties with those of cement Concrete substrate, used for runways. Basic material properties, such as Young’s modulus and coefficient of thermal expansion of an epoxy-based Polymer Concrete containing silicone rubber, and their variations as a function of rubber content and ambient environmental temperature were evaluated. A small-scale model for a runway repair system was fabricated, and temperature-induced strains were measured using fiber Bragg grating sensors. The results were compared with those from finite element analysis of the model to estimate the validity of the simulation technique. Finally, a real maintenance model was analyzed, and the temperature-induced stresses at the substrate/repair material interface, caused by exposure to solar radiation for seven days each during (summer and winter), were closely investigated.
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stress analysis of runway repaired using compliant Polymer Concretes with consideration of cure shrinkage
Composite Structures, 2015Co-Authors: Kyungchae Jung, Intaek Roh, Seunghwan ChangAbstract:Abstract When Polymer Concretes are used to repair runway pavement, difficulties can result, including stress concentration and premature failure. These difficulties are generated by the differences in the mechanical properties of the Polymer Concrete used as the repair material and the cement Concrete of the substrate. In particular, the mechanical properties of Polymer Concretes, including the coefficient of thermal expansion, have significant effects on the behavior of a repaired runway. Additionally, the cure shrinkage of the repair material is one of the main factors in the premature failure of the repaired part. To investigate the stresses generated in materials and determine the feasibility of using a Polymer Concrete as a repair material for runway repair, finite element analyses were carried out by considering the environmental conditions and cure shrinkage of Polymer Concretes. By replacing some amount of the epoxy resin in the standard Polymer Concrete with silicone rubber, compliant Polymer Concretes were developed, and it was found that these compliant Polymer Concretes were able to considerably reduce the generated stress.
Karim S. Rebeiz - One of the best experts on this subject based on the ideXlab platform.
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flexural strength of reinforced Polymer Concrete made with recycled plastic waste
Aci Structural Journal, 1996Co-Authors: Karim S. Rebeiz, David W FowlerAbstract:Investigators evaluated the flexural behavior and strength prediction of steel-reinforced Polymer Concrete (PC) using unsaturated polyester resins based on recycled polyethylene terephthalate (PET) plastic waste. Most beams were singly reinforced with steel bars in the tensile zone. Some beams used double reinforcement with steel bars in the tensile and compression zones. Test results revealed that very good flexural strength can be obtained with reinforced PC using unsaturated polyester resins based on recycled PET. Researchers first investigated prediction of the ultimate flexural strength of steel-reinforced PC beams by using the traditional American Concrete Institute (ACI) approach developed specifically for steel-reinforced portland cement Concrete. The findings of this analysis revealed that the ACI method produces conservative results when applied to reinforced PC. An alternative method of predicting the ultimate flexural strength of PC is introduced using multiple regression analysis on the experimental data.
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precast use of Polymer Concrete using unsaturated polyester resin based on recycled pet waste
Construction and Building Materials, 1996Co-Authors: Karim S. RebeizAbstract:Abstract The strength properties and behaviour of unreinforced and reinforced Polymer Concrete ( pc ) using an unsaturated polyester resin based on recycled polyethylene terephthalate ( pet ) plastic waste are reported. The results obtained show that resins based on recycled pet can be used to produce good quality pc for precast applications such as utility components, transportation components, machine bases and building components. The use of recycled pet in pc helps in reducing the cost of the material, solving some of the solid waste problems posed by plastics and saving energy.
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mechanical properties of Polymer Concrete systems made with recycled plastic
Aci Materials Journal, 1994Co-Authors: Karim S. Rebeiz, David W Fowler, Donald R PaulAbstract:The mechanical properties of various Polymer Concrete (PC) systems using unsaturated polyester resins based on recycled polyethylene terephthalate (PET) plastic waste were evaluated. Resins using recycled PET offer the possibility of a lower source cost of materials for making useful PC products. Also, the recycling of PET in PC would help solve some of the solid waste problems posed by plastics and save energy.
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recommended design procedure in shear for steel reinforced Polymer Concrete
Aci Structural Journal, 1993Co-Authors: Karim S. Rebeiz, Sleiman P Serhal, David W FowlerAbstract:The conventional ACI-ASCE design approach to shear developed for reinforced portland cement Concrete does not yield very good results when applied to reinforced Polymer Concrete (PC). A new procedure that combines the techniques of dimensional analysis and statistical regression analysis is therefore recommended for steel-reinforced PC beams without web reinforcement. The PC beams were made using unsaturated polyester resins and were designed in such a way to achieve a wide range of values in the variables affecting the shear strength of reinforced PC. The new procedure gives excellent results for both short beams and long beams.
Intaek Roh - One of the best experts on this subject based on the ideXlab platform.
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thermal behavior and performance evaluation of epoxy based Polymer Concretes containing silicone rubber for use as runway repair materials
Composite Structures, 2015Co-Authors: Kyungchae Jung, Intaek Roh, Seunghwa ChangAbstract:Abstract This paper investigates the applicability of a Polymer Concrete as a repair material for runways by evaluating the differences in its thermal behaviors and mechanical properties with those of cement Concrete substrate, used for runways. Basic material properties, such as Young’s modulus and coefficient of thermal expansion of an epoxy-based Polymer Concrete containing silicone rubber, and their variations as a function of rubber content and ambient environmental temperature were evaluated. A small-scale model for a runway repair system was fabricated, and temperature-induced strains were measured using fiber Bragg grating sensors. The results were compared with those from finite element analysis of the model to estimate the validity of the simulation technique. Finally, a real maintenance model was analyzed, and the temperature-induced stresses at the substrate/repair material interface, caused by exposure to solar radiation for seven days each during (summer and winter), were closely investigated.
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stress analysis of runway repaired using compliant Polymer Concretes with consideration of cure shrinkage
Composite Structures, 2015Co-Authors: Kyungchae Jung, Intaek Roh, Seunghwan ChangAbstract:Abstract When Polymer Concretes are used to repair runway pavement, difficulties can result, including stress concentration and premature failure. These difficulties are generated by the differences in the mechanical properties of the Polymer Concrete used as the repair material and the cement Concrete of the substrate. In particular, the mechanical properties of Polymer Concretes, including the coefficient of thermal expansion, have significant effects on the behavior of a repaired runway. Additionally, the cure shrinkage of the repair material is one of the main factors in the premature failure of the repaired part. To investigate the stresses generated in materials and determine the feasibility of using a Polymer Concrete as a repair material for runway repair, finite element analyses were carried out by considering the environmental conditions and cure shrinkage of Polymer Concretes. By replacing some amount of the epoxy resin in the standard Polymer Concrete with silicone rubber, compliant Polymer Concretes were developed, and it was found that these compliant Polymer Concretes were able to considerably reduce the generated stress.