Durability characteristics of nano-GFRP composite reinforcing bars for concrete structures in moist and alkaline environments

Abstract In this study, nano glass fibre-reinforced polymer (nano-GFRP) composite reinforcing bars (rebar) for concrete structures were fabricated, and their performance during prolonged exposure to water and alkaline solutions was evaluated. Nano-GFRP rebar was prepared using the pultrusion method by adding nanomaterials to vinyl ester resin. The nanomaterials, including silica (SiO 2 ), alumina (Al 2 O 3 ), and silicon nitride (Si 3 N 4 ), were added to vinyl ester resin at 1, 3, and 5 wt.%. After exposure to water and alkaline solutions for 50 and 115 days, tensile strength tests were carried out, and the moisture diffusion coefficient was determined and compared with that of general GFRP rebar. The results indicated that the tensile residual strengths of nano-GFRP rebar and general GFRP rebar were almost the same after exposure to water, whereas the tensile residual strength of nano-GFRP rebar was higher than that of general GFRP rebar after exposure to alkaline solution. The moisture diffusion coefficient of the alumina and silicon nitride samples increased slightly after exposure to alkaline solution, but the silica sample had a higher moisture diffusion coefficient; however, the moisture diffusion coefficients of all nano-GFRP rebar samples were comparable to that of general GFRP rebar.

[1]  Mark R. VanLandingham,et al.  Effects of ultraviolet radiation exposure on vinyl ester resins: characterization of chemical, physical and mechanical damage , 2003 .

[2]  M. Aiello,et al.  Moisture Effects on Elastic and Viscoelastic Properties of CFRP Rebars and Vinylester Binder , 2006 .

[3]  P. Vijay.  Aging and design of concrete members reinforced with GFRP bars , 1999 .

[4]  M. Misra,et al.  Preparation and Properties of Vinylester Resin/Clay Nanocomposites , 2006 .

[5]  Yaping Zheng,et al.  The Influence of High Content Nano-Al2O3 on the Properties of Epoxy Resin Composites , 2009 .

[6]  V. Srivastava.  Influence of water immersion on mechanical properties of quasi-isotropic glass fibre reinforced epoxy vinylester resin composites , 1999 .

[7]  Jong-Pil Won,et al.  Mechanical Properties and Microstructures of Gfrp Rebar after Long-Term Exposure to Chemical Environments , 2007 .

[8]  Khaled Aouadi,et al.  Effects of environmental exposure on fiber-reinforced plastic (FRP) materials used in construction , 1997 .

[9]  V. Kodur,et al.  Thermal and mechanical characterization of fibre reinforced polymers, concrete, steel and insulation materials for use in numerical fire endurance modelling , 2007 .

[10]  Jong-Pil Won,et al.  The effect of exposure to alkaline solution and water on the strength–porosity relationship of GFRP rebar , 2008 .

[11]  A. Khanna,et al.  “Effect of nano-ZnO particles on the corrosion behavior of alkyd-based waterborne coatings” , 2009 .

[12]  H. Fischer.  Polymer nanocomposites: from fundamental research to specific applications , 2003 .

[13]  V. Karbhari,et al.  Durability evaluation of moderate temperature cured E-glass/vinylester systems , 2004 .

[14]  R. Landel,et al.  Mechanical Properties of Polymers and Composites , 1993 .

[15]  Emmanuel P. Giannelis,et al.  Polymer Layered Silicate Nanocomposites , 1996 .

[16]  R. Velmurugan,et al.  Effect of Clay Dispersion on Mechanical, Thermal and Vibration Properties of Glass Fiber-Reinforced Vinyl Ester Composites , 2008 .

[17]  A. Khanna,et al.  Effect of nano-Al2O3 particles on the corrosion behavior of alkyd based waterborne coatings , 2009 .

[18]  F. Micelli,et al.  Durability of FRP rods for concrete structures , 2004 .

[19]  Youssef K. Hamidi,et al.  Effect of Nanoclay Content on Void Morphology in Resin Transfer Molded Composites , 2008 .

[20]  E. Giannelis,et al.  Synthesis and properties of new poly(dimethylsiloxane) nanocomposites , 1995 .

[21]  Li-xin Zhao,et al.  Tribological performance of nano-Al2O3 reinforced polyamide 6 composites , 2006 .

[22]  J. Johnston,et al.  Nano-structured silicas and silicates––new materials and their applications in paper , 2004 .

[23]  Kestur Gundappa Satyanarayana,et al.  Nanocomposites: synthesis, structure, properties and new application opportunities , 2009 .

[24]  R. Laine,et al.  Organic–Inorganic Nanocomposites with Completely Defined Interfacial Interactions , 2001 .

[25]  Chan-Gi Park,et al.  Effect of Environmental Exposure on the Mechanical and Bonding Properties of Hybrid FRP Reinforcing Bars for Concrete Structures , 2006 .

[26]  A. Hammami,et al.  Durability and environmental degradation of glass‐vinylester composites , 2004 .

[27]  L. Carlsson,et al.  Modified single fiber fragmentation test procedure to study water degradation of the fiber/matrix interface toughness of glass/vinylester , 2009 .

[28]  Suong V. Hoa,et al.  Organoclay-modified high performance epoxy nanocomposites , 2005 .

[29]  Jian Sun,et al.  Effect of nanosilica on the properties of polyester‐based polyurethane , 2003 .

[30]  Jamal Aalaie,et al.  Preparation and Properties of Epoxy‐Clay Nanocomposites , 2007 .

[31]  A. Nanni.  Guide for the Design and Construction of Concrete Reinforced with FRP Bars (ACI 440.1R-03) , 2005 .

[32]  X. Kornmann.  Synthesis and characterisation of thermoset-clay nanocomposites , 1999 .

[33]  Xin Wang,et al.  Tensile Properties of CFRP and Hybrid FRP Composites at Elevated Temperatures , 2009 .

[34]  B. Eggins.  Analytical Techniques in the Sciences , 2002 .

[35]  Brahim Benmokrane,et al.  Glass fibre reinforced plastic (GFRP) rebars for concrete structures , 1995 .

[36]  A. Kinloch,et al.  The fracture of glass-fibre-reinforced epoxy composites using nanoparticle-modified matrices , 2008 .

[37]  Jong-Pil Won,et al.  Service Life Prediction of Gfrp Rebars in an Alkaline Environment , 2007 .

[38]  F. Micelli,et al.  Tensile Characterization of FRP Rods for Reinforced Concrete Structures , 2003 .