Flexural behaviour of NSM CFRP laminate strip systems in concrete using stiff and flexible adhesives

Cruz, José Ricardo; Seręga, Szymon; Sena-Cruz, José; Pereira, Eduardo; Kwiecień, Arkadiusz; Zając, Bogusław

doi:10.1016/j.compositesb.2020.108042

Cited by 24 publications

(8 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ability of flexible PU adhesives to redistribute shear stress over a large area, unlike stiff epoxy [12] and mineral adhesives [13], caused the development of these adhesives in the composite strengthening of masonry and concrete structures. PSpolyurethane has been applied as a flexible adhesive layer and matrix of composite fibers in FRPU systems, bonding composite laminates to concrete elements as externally bonded (EB) systems [4,14] and near-surface mounted (NSM) systems [14]. PU flexible adhesives and matrices were also used as FRPU in masonry applications [3,15,16].…”

Section: Introductionmentioning

confidence: 99%

Durability of PS-Polyurethane Dedicated for Composite Strengthening Applications in Masonry and Concrete Structures

Kwiecień

Stryszewska

et al. 2020

Polymers

Self Cite

View full text Add to dashboard Cite

Polyurethane flexible joints (PUFJ) and fiber reinforced polyurethanes (FRPU) have shown great potential in the repair and protection of masonry and concrete structures. However, some questions have been raised about the durability of such solutions. The accelerated weathering and thermal stability tests carried out so far have shown the mechanical stability of PS-polyurethane in temperatures up to 100 °C and some UV-induced surface degradation. The paper reports the results from tensile tests of PS-polyurethane, used in the technologies mentioned above after being subjected to aging in different corrosive factors, a thermal analysis of unaged polymer which consists of DSC-TGA and dilatometry studies, and SEM-microscopy observation of the specimens with the indication of the elemental composition (EDS). PS-polyurethane showed low sensitivity to weathering with exposition to UV-radiation, some reactiveness to aqueous environments of a different chemical nature, and resistivity to soil and freezing in both air and water. SEM observations indicated changes in the composition of mineral fillers as the main effect of immersion in different water solutions. DSC-TGA studies showed the thermal stability of PS-polyurethane up to 200 °C and degradation proceeding in five stages. Dilatometry studies revealed that the first-degree thermal degradation over 200 °C causes a serious loss of mechanical properties.

show abstract

Section: Introductionmentioning

confidence: 99%

Durability of PS-Polyurethane Dedicated for Composite Strengthening Applications in Masonry and Concrete Structures

Kwiecień

Stryszewska

et al. 2020

Polymers

Self Cite

View full text Add to dashboard Cite

show abstract

“…Finally, the preformed FRP bars with different surface configurations were thermally cured, and then fixed-scale cut. The rib spacing was controlled by the rotational speed (n winding ) of winding device, which could be calculated by equation (1). The shallow or The first letter G or H represents GFRP bar or HFRP bar specimen.…”

Section: Frp Bar Productionmentioning

confidence: 99%

“…The intrinsic advantages of high specific strength and stiffness, corrosion-resistance, resistant-fatigue and non-magnetization of fiber reinforced polymer (FRP) bars make it ideal candidate to replace steel rod in harsh service environment. [1][2][3][4][5][6][7] In last decades, the extensive application of FRP reinforced structure in the field of civil engineering has been limited owing to the brittleness and anisotropy characteristics of FRP, which has been recognized by many scholars. [8][9][10][11][12][13] One approach for solving the problem of FRP with brittleness characteristic is to combine two or more different types of fibers with resin matrix to achieve the purpose of graded fracture and obtain ductile feature, and that is usually called the hybrid fiber reinforced polymer (HFRP).…”

Section: Introductionmentioning

confidence: 99%

Transverse shear properties of fiber reinforced polymer bars with different reinforced phases

Wen¹,

Pang²,

Fang³

et al. 2021

Journal of Composite Materials

View full text Add to dashboard Cite

In this study, a total of 105 shear specimens of fiber reinforced polymer bars with different reinforced phases, including the glass fiber, the hybrid of carbon fiber with glass fiber, and the hybrid of steel wire with glass fiber, were prepared to systematically investigate their transverse shear properties. The surface configuration of specimens, the performance characteristics and distribution pattern of reinforced phase were mainly regarded as variables. The results showed the shear strengths of glass fiber reinforced polymer bar specimens increased from 247.9 MPa to 263.5 MPa as the rib depth changed from shallow ribs to deep ribs, and their ultimate strain decreased from 0.374 to 0.328 with the increase in rib spacing from 8 mm to 16 mm. The shear strengths of carbon/glass hybrid fiber reinforced polymer (C/G HFRP) bar specimens declined from 247.4 MPa to 226.3 MPa as the distribution pattern of carbon fiber changed from centralized distribution to dispersed distribution. The shear strength of C/G HFRP bars decreased from 256.5 MPa to 247.4 MPa as the ratio of glass fiber to carbon fiber ranged from 0:1 to 1:4, and increased from 138.7 MPa to 214.8 MPa for steel wire/glass HFRP bars as the volumetric fraction of steel wire replacing glass fiber increased from 0 to 33.3%. This indicated that the surface configuration of specimen, the distribution pattern of fiber, and the performance characteristics of reinforced phase have great effects on the ultimate strain and shear strength of FRP bars, respectively.

show abstract

“…Filling of cracks by external injection with bonding material such as epoxy resin or self-healing methods [ 5 , 6 ] use mainly stiff and high strength, but hardly deformable materials, which generate stress concentrations in concrete weakened by micro-cracks [ 4 ]. Recovering of strength and stiffness in damaged cross-sections leads also to the use of composite materials [ 7 , 8 ] with various adhesives [ 9 , 10 ].…”

Section: Introductionmentioning

confidence: 99%

Polymer Flexible Joint as a Repair Method of Concrete Elements: Flexural Testing and Numerical Analysis

et al. 2020

Self Cite

View full text Add to dashboard Cite

Polymer Flexible Joint (PFJ) is a method for repairs of concrete elements, which enables carrying loads and large deformations effectively. This article presents the possibility of applying PFJ on beams subjected to bending and describes the influence of such joints on concrete elements. An experimental investigation was conducted to determine the behavior of concrete in a four-point bending test. The research program included flexural tests of plain concrete elements with a notch, as well as tests of elements which were repaired with PFJ after failure. Based on the experimental results, the numerical characteristics of analyzed polymer and concrete were calibrated. A nonlinear numerical model is developed, which describes the behavior of concrete elements and polymer in the experiments. The model is used to numerically analyze deformations and stresses under increasing load. The influence of flexible joint on concrete elements is described and behavior of elements repaired with PFJ is compared to original elements. Particular attention was paid to the stress redistribution in concrete. The application of flexible joint positively influences load capacity of the connected concrete elements. Furthermore, because of stress redistribution, connected elements can bear larger deformations than original ones. PFJ can therefore be considered an efficient repair method for connecting concrete elements.

show abstract

Flexural behaviour of NSM CFRP laminate strip systems in concrete using stiff and flexible adhesives

Cited by 24 publications

References 13 publications

Durability of PS-Polyurethane Dedicated for Composite Strengthening Applications in Masonry and Concrete Structures

Durability of PS-Polyurethane Dedicated for Composite Strengthening Applications in Masonry and Concrete Structures

Transverse shear properties of fiber reinforced polymer bars with different reinforced phases

Polymer Flexible Joint as a Repair Method of Concrete Elements: Flexural Testing and Numerical Analysis

Contact Info

Product

Resources

About