Improvement of flammability resistance of epoxy adhesives used in infrastructure applications

2007 ◽  
Vol 34 (3) ◽  
pp. 323-330 ◽  
Author(s):  
Lixin Wu ◽  
Suong V Hoa ◽  
Heng Wang
Keyword(s):  
Epoxy Adhesive ◽  
Polymer Concrete ◽  
Limit Oxygen Index ◽  
Index Number ◽  
Test Results ◽  
Epoxy Adhesives ◽  
Reinforced Polymer ◽  
Average Residual ◽  
Fire Endurance ◽  
Fibre Reinforced Polymer

Fire endurance of fibre-reinforced-polymer (FRP) concrete systems is crucial for safe use of FRPs in the construction industry. Nanoclay was introduced into epoxy resin to retard flame spread and improve the fire endurance of bonds between FRP and concrete. Test results show that the addition of nanoclay can greatly improve the flame retardancy of epoxy. With only 2% nanoclay, the limit oxygen index number of epoxy increases by 5 and 10 using two types of mixing methods developed at the Concordia Centre for Composites. The epoxy with the addition of nanoclay possesses self-extinguishing properties, whereas the epoxy without the addition of nanoclay burned completely. After exposure to 260 °C for 2 h, the FRP-concrete system using epoxy and 2% nanoclay adhesive showed 23% greater average residual bonding strength than that using control epoxy adhesive. The nanoclay used in this study is a nontoxic and inexpensive material that may fulfill the requirements for civil engineering applications.Key words: fire resistance, fibre-reinforced polymer, concrete, bond, adhesive, nanoclay, epoxy.

scholarly journals Compressive behaviour of square fibre-reinforced polymer–concrete–steel hybrid multi-tube concrete columns

2017 ◽  
Vol 21 (8) ◽  
pp. 1162-1172 ◽  
Author(s):  
Chunwa Chan ◽  
Tao Yu ◽  
Shishun Zhang
Keyword(s):  
Axial Strain ◽  
Strain Curve ◽  
Concrete Columns ◽  
Experimental Program ◽  
Polymer Concrete ◽  
Test Results ◽  
Steel Tubes ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Polymer Tube

Fibre-reinforced polymer–concrete–steel hybrid multi-tube concrete columns are a new form of columns recently proposed at the University of Wollongong. An multi-tube concrete column consists of an external fibre-reinforced polymer tube and a number of circular internal steel tubes, with the space inside all the tubes filled with concrete. This article presents the first ever experimental study on square multi-tube concrete columns. The experimental program included a total of 14 stub column specimens tested under axial compression, with the test variables being the thickness of the external fibre-reinforced polymer tube, and the dimensions and configuration of the internal steel tubes. The test results demonstrated that the concrete in the square multi-tube concrete columns was very effectively confined by the multiple tubes, and that the buckling of the internal steel tubes was completely prevented, leading to full structural utilization of the materials and a very ductile response. The test results also showed that the behaviour of the concrete in the square multi-tube concrete columns was significantly superior to that in the corresponding square concrete-filled fibre-reinforced polymer tubes, in terms of the compressive strength, the ultimate axial strain and the stiffness of the second branch of the stress–strain curve. A simple analytical model proposed for the axial load-axial strain curve of square multi-tube concrete columns is also presented and is shown to provide reasonable and conservative predictions of the test results.

scholarly journals Strengthening of self-compacting reinforced concrete deep beams containing circular openings with CFRP

2018 ◽  
Vol 162 ◽  
pp. 04015
Author(s):  
Nabeel Al-Bayati ◽  
Bassman Muhammad ◽  
Murooj Faek
Keyword(s):  
Ultimate Load ◽  
Test Results ◽  
Load Path ◽  
Deep Beams ◽  
Self Compacting Concrete ◽  
Reinforced Polymer ◽  
Web Reinforcement ◽  
Externally Bonded ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer

This paper shows the behavior of reinforced self-compacting concrete deep beams with circular openings strengthened in shear with various arrangements of externally bonded Carbon Fibre Reinforced Polymer (CFRP). Six simply supported deep beams were constructed and tested under two points load up to the failure for this purpose. All tested beams had same geometry, compressive strength, shear span to depth ratio, main flexural and web reinforcement. The variables considered in this study include the influence of fiber orientation, utilizing longitudinal CFRP strips with vertical strips and area of CFRP. The test results indicated that the presence of the circular openings in center of load path reduce stiffness and ultimate strength by about 50% when compared with solid one, also it was found that the externally bonded CFRP can significantly increase the ultimate load and enhance the stiffness of deep beam with openings.

scholarly journals Numerical parametric studies on the fire endurance of fibre-reinforced-polymer-confined concrete columns

2004 ◽  
Vol 31 (6) ◽  
pp. 1090-1100 ◽  
Author(s):  
L A Bisby ◽  
V KR Kodur ◽  
M F Green
Keyword(s):  
Reinforced Concrete ◽  
Holistic Approach ◽  
Concrete Columns ◽  
Reinforced Concrete Columns ◽  
Reinforced Polymer ◽  
Fire Endurance ◽  
Fibre Reinforced Polymer ◽  
Parametric Studies ◽  
Parking Garages ◽  
Promising Application

Confinement of reinforced concrete columns by circumferential fibre reinforced polymer (FRP) wraps is a promising application of FRP materials for structural strengthening and seismic upgrading of deteriorated or under-strength members. However, if this technique is to be used in buildings, parking garages, and industrial structures, then the ability of FRP materials and FRP-wrapped columns to withstand the effects of fire must be demonstrated and evaluated. This paper presents the results of parametric studies conducted using a previously presented and partially validated numerical fire simulation model to investigate the effects of a number of parameters on the fire behaviour of FRP-wrapped reinforced concrete columns. It is demonstrated that appropriately designed and adequately protected FRP-wrapped reinforced concrete columns are capable of achieving fire endurances equivalent to conventionally reinforced concrete columns. Furthermore, this study also suggests that a holistic approach to the fire design of FRP-wrapped members is required, rather than an approach based on the specific performance of the FRP materials. Design recommendations for the fire-safe design of FRP-wrapped concrete columns are presented and discussed.Key words: reinforced concrete, rehabilitation, strengthening, fibre reinforced polymer, fire endurance, fire insulation, numerical modelling.

Seismic Performance of Natural Fibre Reinforced Polymer-Concrete Bridge Piers

2015 ◽  
Vol 1120-1121 ◽  
pp. 1480-1484 ◽  
Author(s):  
Jia Xin Chen ◽  
Nawawi Chouw
Keyword(s):  
Seismic Performance ◽  
Construction Materials ◽  
Natural Fibre ◽  
Polymer Concrete ◽  
Reinforced Polymer ◽  
Earthquake Resistant Structures ◽  
Future Earthquake ◽  
Fibre Reinforced Polymer ◽  
New Construction ◽  
Shake Table Experiments

This paper addresses the usage of new construction materials made of natural fibre reinforced polymer and concrete composite for future earthquake-resistant structures. The structure considered is a simple circular bridge pier. To evaluate the seismic performance of the structure shake table experiments were performed. To reveal the consequence of the magnitude of the ground excitation for the structure the effect of a gradual increase of the peak ground displacement is investigated. The results show that although external damage to the structure cannot be observed the bond between polymer and concrete is a significant factor that determines the performance of the structure.

Review of shear design methods for reinforced concrete beams strengthened with fibre reinforced polymer sheets

2001 ◽  
Vol 28 (2) ◽  
pp. 271-281 ◽  
Author(s):  
Christophe Deniaud ◽  
JJ Roger Cheng
Keyword(s):  
Reinforced Concrete ◽  
Glass Fibre ◽  
Mechanical Model ◽  
Concrete Beams ◽  
Design Methods ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Shear Design ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

This paper reviews the different shear design methods found in the literature for reinforced concrete beams strengthened externally with fibre reinforced polymer (FRP) sheets and compares the adequacy of each method by using the test results from the University of Alberta. The FRP shear design methods presented include the effective FRP strain and the bond mechanism criteria, the strut-and-tie model, the modified compression field theory, and a mechanical model based on the strip method with shear friction approach. Sixteen full-scale T-beam test results were used in the evaluation. Two web heights of 250 and 450 mm and two ready mix concrete batches of 29 and 44 MPa were used in the test specimens. Closed stirrups were used with three spacings: 200 mm, 400 mm, and no stirrups. Three types of FRP were used to strengthen externally the web of the T-beams: (i) uniaxial glass fibre, (ii) triaxial (0/60/–60) glass fibre, and (iii) uniaxial carbon fibre. The results showed that the mechanical model using the strip method with shear friction approach evaluates better the FRP shear contribution. The predicted capacities from this mechanical model are also found conservative and in excellent agreement with the test results.Key words: beams, carbon fibres, composite materials, fibre reinforced polymers, glass fibres, rehabilitation, reinforced concrete, shear strength, sheets, tests.

Experimental Study on CFRP-Bonded Steel Plates with Thickness Reduction Using Underwater Epoxy

2011 ◽  
Vol 117-119 ◽  
pp. 373-379
Author(s):  
Xiao Chen ◽  
Yasuo Kitane ◽  
Yoshito Itoh
Keyword(s):  
Epoxy Adhesive ◽  
Steel Plates ◽  
Fiber Reinforced Polymer ◽  
Structural Performance ◽  
Carbon Fiber Reinforced Polymer ◽  
Curing Process ◽  
Test Results ◽  
Initial Stiffness ◽  
Reinforced Polymer ◽  
Loading Tests

This paper presents a series of uniaxial loading tests on the thickness-reduced steel plates bonded with carbon fiber reinforced polymer (CFRP) strand sheets using underwater epoxy as adhesive. Four sets of material test are carried out on epoxy coupons at different curing times. Repaired performance of CFRP-bonded steel plates is investigated in terms of initial stiffness, yield strength, and failure mode of the specimens. Test results showed that the structural performance of CFRP-bonded steel plates does not reach the expected design level due to a slow curing process of epoxy adhesive in this study. The curing effects of epoxy adhesive on the repaired performance are discussed.

scholarly journals Possibilities of Increasing Effectiveness of RC Structure Strengthening with FRP Materials

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1387
Author(s):  
Wit Derkowski ◽  
Rafał Walczak
Keyword(s):  
Composite Laminates ◽  
Civil Engineering ◽  
Adhesive Layer ◽  
Epoxy Adhesive ◽  
Building Structures ◽  
Complex Behaviour ◽  
Rc Structures ◽  
Flexural Strengthening ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

Modern composite materials based on non-metallic continuous fibres are increasingly used in civil engineering to strengthen building structures. In the strengthening of reinforced concrete (RC) structures, the utilisation of externally bonded fibre-reinforced polymer (FRP) composites is only up to 35% because of the pilling-off failure mechanism. This problem can be solved using pre-tensioned composite laminates. Due to more complex behaviour, the strengthening of structures by means of prestressing technology needs a careful design approach and a full understanding of the behaviour of both the materials and elements. The advantages and risks of the presented technology, which may determine the success of the entire project, will be highlighted in the paper. The possibility of using a flexible adhesive layer in carbon fibre reinforced polymer (CFRP) strengthening applications for flexural strengthening of RC elements, as an innovative solution in civil engineering, will also be presented. Parallel introduction of the flexible adhesive layer (made of polyurethane masses) and a traditional epoxy adhesive layer in one strengthening system was investigated in the laboratory tests. This solution was used for the repair and protection of a previously damaged RC beam against brittle failure.

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