Compressive Behavior of Concrete Confined with GFRP Tubes and Steel Spirals

Abstract

This paper presents the experimental results and analytical modeling of the axial compressive behavior of concrete cylinders confined by both glass fiber-reinforced polymer (GFRP) tube and inner steel spiral reinforcement (SR). The concrete structure is termed as GFRP-SR confined concrete. The number of GFRP layers (1, 2, and 3 layers) and volumetric ratios of SR (1.5% and 3%) were the experimental variables. Test results indicate that both GFRP tube and SR confinement remarkably increase the ultimate compressive strength, energy dissipation capacity, and ductility of concrete. The volumetric ratio of SR has a more pronounced influence on the energy dissipation capacity of confined concrete with more GFRP layers. In addition, a stress-strain model is presented to predict the axial compressive behavior of GFRP-SR confined concrete. Comparisons between the analytical results obtained using the proposed model and experimental results are also presented.

Residual Axial Bearing Capacity of Concrete-Filled Circular Steel Tubular Columns (CFCSTCs) after Transverse Impact

“…Attention also has been paid to Concrete Filled Fiber Reinforced Polymer (FRP) Tubes, in view of their anti-corrosion properties, which can be better adapted to corrosive environments than CFST [11][12][13][14][15][16]. However, compared with concrete filled FRP Tubes (CFFT), CFSTs are preferred when involving transverse impacts, because steel has much better toughness than FRP when subjected to direct impacts.…”

Influence of HPFRCC Compressive Strength and Confinement on Concrete

“…Strengthening with reinforced fine-grained concrete layer (R. Ortlepp & S. Ortlepp, 2017) or HPFRCC (Daugevičius & Valivonis, 2013 allows evaluating compressive resistance of external layer. However, the review shows that usually the confinement effect is evaluated (Thermou & Hajirasouliha, 2018;De Caso y Basalo et al, 2012;Cascardi, Longo, Micelli, & Aiello, 2017;Trapko, 2013;Huang, Sun, Yan, & Zhu, 2015;Zhou, Bi, Wang, & Zhang, 2016;Colajanni, De Domenico, Recupero, & Spinella, 2014;Napoli & Realfonzo, 2016;Chastre & Silva, 2010;Tamuzs, Tepfers, & Sparnins, 2006).…”

“…Resistance due to provided confinement or direct interception of compressive stresses can differ in times, because the compressive strength of concrete is much bigger than tensile. Most equations which evaluate the confinement effect require the lateral strain (Thermou & Hajirasouliha, 2018;De Caso y Basalo et al, 2012;Huang et al, 2015;Colajanni et al, 2014;Napoli & Realfonzo, 2016;Chastre & Silva, 2010;Tamuzs et al, 2006;Ombres, 2014;Campione, La Mendola, Monaco, Valenza, & Fiore, 2015;Cascardi, Aiello, & Triantafillou, 2017) or strength (Trapko, 2013(Trapko, , 2014Zhou et al, 2016;Wei & Wu, 2014) of external material. Evaluation of direct interception of compressive stresses requires compatibility of strains.…”

Experimental and Analytical Modeling of GFRP Strengthened Grouted Mortarless Masonry Prisms

“…For many years, strengthening using external confinement has been considered an effective technique to upgrade or retrofit existing reinforced concrete and masonry compressive column components [9]. Recently, Fiber Reinforced Polymers (FRP) have been widely researched and used in strengthening and retrofitting engineering structures to increase the carrying capacity or ductility because of their significant characteristics such as high strength and increased deformation capability [10][11][12][13], and there are lots of functional analytical models for better understanding and explanation for FRP confinement [14,15].…”