Deformable Polyurethane Joints and Fibre Grids for Resilient Seismic Performance of Reinforced Concrete Frames with Orthoblock Brick Infills

Rousakis, Theodoros; İlki, Alper; Kwiecień, Arkadiusz; Viskovic, Alberto; Gams, Matija; Triller, Petra; Ghiassi, Bahman; Benedetti, Andrea; Rakicevic, Zoran; Colla, Camilla; Halıcı, Ömer Faruk; Zając, Bogusław; Hojdys, Łukasz; Krajewski, Piotr; Rizzo, Fabio; Vanian, Vachan; Sapalidis, Anastasios; Papadouli, Efthimia; Bogdanovic, Aleksandra

doi:10.3390/polym12122869

Cited by 31 publications

(31 citation statements)

References 25 publications

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“…It was confirmed in [20] that the application of polymer elements placed between structures may prevent damaging collisions during earthquakes, which means that the approach can be considered as an effective pounding mitigation technique. It should also be underlined that, in the case of structures erected in seismic areas, the aspect of structural damping is very important, and innovative solutions using dissipative viscoelastic elastomers like PolyUrethane Flexible Joints (PUFJ) and Fibre-Reinforced PolyUrethane (FRPU) meet these requirements (see [21][22][23][24]).…”

Section: Introduction 1the Issue Of the Pounding Of Structures Due To Seismic Load And The Existing Solutionsmentioning

confidence: 99%

“…Another approach that can be considered to reduce the negative effects of pounding between insufficiently separated structures is filling the gap using the already mentioned viscoelastic materials ( [20]) in the form of composite materials, either externally bonded [25,26] or injected in the cracks [27]. These types of materials have been proposed as an innovative strengthening or repair solution in masonry or infill structures [21,28,29]. Another type of composite for the prevention of earthquake damage consisting of elastomer and steel was reported in [30].…”

Section: Introduction 1the Issue Of the Pounding Of Structures Due To Seismic Load And The Existing Solutionsmentioning

confidence: 99%

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Highly Dissipative Materials for Damage Protection against Earthquake-Induced Structural Pounding

et al. 2021

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It is a common situation that seismic excitations may lead to collisions between adjacent civil engineering structures. This phenomenon, called earthquake-induced structural pounding, may result in serious damage or even the total collapse of the colliding structures. Filling the gap between two buildings erected close to one another by using visco-elastic materials can be considered to be one of the most effective methods to avoid seismic pounding. In this paper, a new polymer–metal composite material made of polyurethane and closed-cell aluminum foam is proposed as a pounding energy absorber for protection against earthquake hazards. The composite was created in two versions, with and without an adhesive interface. A series of experiments which reflect the conditions of seismic collision were performed: quasi-static compression, dynamic uniaxial compression and low-cycle dynamic compression with 10 loops of unloading at 10% strain. The composite material’s behavior was observed and compared with respect to uniform material specimens: polymer and metal foam. The experimental results showed that the maximum energy absorption efficiency in the case of the new material with the bonding layer was improved by 34% and 49% in quasi-static and dynamic conditions, respectively, in comparison to a sole polymer bumper. Furthermore, the newly proposed composites dissipated from 35% to 44% of the energy absorbed in the cyclic procedure, whereas the polymer specimen dissipated 25%. The capacity of the maintenance of the dissipative properties throughout the complete low-cycle loading was also satisfactory: it achieved an additional 100% to 300% of the energy dissipated in the first loading–unloading loop.

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Section: Introduction 1the Issue Of the Pounding Of Structures Due To Seismic Load And The Existing Solutionsmentioning

confidence: 99%

Section: Introduction 1the Issue Of the Pounding Of Structures Due To Seismic Load And The Existing Solutionsmentioning

confidence: 99%

Highly Dissipative Materials for Damage Protection against Earthquake-Induced Structural Pounding

et al. 2021

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“…Flexible joints are used in forms of PUFJ (polyurethane flexible joints) and FRPU (fiber-reinforced polyurethane). These structural connectors can be used as repair, strengthening or protection solutions in RC (reinforced concrete) and masonry structures, because they are capable of transferring high loads and large deformations [ 8 ]. They are constructed from special polyurethanes of non-linear and visco-elastic characteristic; thus, different material properties can be expected in cases of various strain rates [ 9 ] and various environmental conditions [ 10 ].…”

Section: Introductionmentioning

confidence: 99%

Modelling of Flexible Adhesives in Simple Mechanical States with the Use of the Darijani–Naghdabadi Strain Tensors and Kirchhoff–de Saint-Venant Elastic Potential

2021

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Practical aspects of modelling of flexible adhesives with the energy conjugate measures of stress and strain of the Darijani–Naghdabadi (D-N) family are discussed. A possibility of description of materials exhibiting non-linear physical characteristics with the use of non-linear geometric relationships and linear elastic constitutive law is considered. Nominal stress vs. stretch relations are specified in cases of simple tension and simple shear with the use of the Kirchhoff–de Saint-Venant elastic potential and D-N energy conjugate stress and strain measures. Obtained theoretical estimates were compared with experimental results of simple tension and simple shear tests performed on Sika PM polyurethane (Cracow, Sika Poland). The deformation rate was fixed in order to minimize the influence of viscosity. Values of parameters in the definition of the D-N strain tensor were optimized in order to provide good agreement between model predictions and experimental results. Observed discrepancies indicate that the proposed approach is not appropriate for constitutive modelling of the PM polymer. The presented approach is proposed to be used as a simple design model providing practical formulas describing the behavior of materials of non-linear characteristics in chosen mechanical states. Admissible values of exponents are discussed regarding its bijectivity in a limited range of variation of principal stretches.

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“…The reinforcement technology usually involves bonding of, steel bars, sheets (flat bars) or fibre-reinforced polymer composites in the tension zone of a component using epoxy adhesives [ 17 , 18 , 19 , 20 ]. Flexible adhesives on the other hand find application mostly in repair of masonry and concrete structures [ 3 , 21 ] and seismic protection of buildings where dissipation of energy and reduction of edge stresses are desirable [ 22 , 23 ]. Lasowicz et al [ 24 ] studied the effectiveness of flexible polyurethane adhesive in vibration reduction of a structure subjected to dynamic loads.…”

Section: Introductionmentioning

confidence: 99%

Rigid and Flexible Double Shear Lap Adhesive Joint at Elevated Temperature—An Experimental Study

Śliwa-Wieczorek

Zając

2021

Polymers

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Double lap adhesive connections made of Sika® PS and Monolith EP2579-1 were studied experimentally in shear tests. The destructive shear tests were conducted under a quasi-static load at 20 °C and 80 °C. The aim was to study the impact of elevated temperature on the load capacity of the joint and make a comparative analysis of the results for two types of adhesives: polyurethane Sika® PS (flexible) and epoxy Monolit EP 2579-1 (rigid). The impact of adhesive layer thickness (t = 1, 2 and 4 mm) on the structural response of the joint was tested in two temperature ranges. A distinct impact of the temperature on the joint deformability was noticed. A visual assessment of the joint failure was performed and the initiation and form of failure was described. At 20 °C, the ultimate loading for epoxy adhesive joint depending on the joint thickness (t) was greater than for the polyurethane joint by, respectively, 282% for t = 1 mm, 88% for t = 2 mm and 279% for t = 4 mm. It was proved that the temperature increases to 80 °C in case of both adhesives reduces the mean destructive force in comparison with the measurements made at 20 °C. For the Sika® PS (PUR two-component polyurethane) adhesive, the greatest load capacity decrease was measured for the joint of thickness t = 2 mm (55%), and in case of the epoxy adhesive for the joint of thickness t = 4 mm (89%). It was found that after reaching the destructive force the flexible joints retain a partial load capacity contrary to the rigid joints.

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Deformable Polyurethane Joints and Fibre Grids for Resilient Seismic Performance of Reinforced Concrete Frames with Orthoblock Brick Infills

Cited by 31 publications

References 25 publications

Highly Dissipative Materials for Damage Protection against Earthquake-Induced Structural Pounding

Highly Dissipative Materials for Damage Protection against Earthquake-Induced Structural Pounding

Modelling of Flexible Adhesives in Simple Mechanical States with the Use of the Darijani–Naghdabadi Strain Tensors and Kirchhoff–de Saint-Venant Elastic Potential

Rigid and Flexible Double Shear Lap Adhesive Joint at Elevated Temperature—An Experimental Study

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