In this study, the feasibility of utilizing the spin casting technique with structural Fibre-Reinforced Polymer (FRP) tubes and eliminating steel reinforcement is explored for the first time. This would make spun-cast FRP tubes (SCFTs) desirable in pole applications, as they are relatively light-weight, protected from deicing salts and other elements by the tube, and have similar flexural resistance to the completely filled FRP tubes (CFFTs). This study evaluates the flexural and bond performances of SCFTs through experimental and analytical investigations. The experimental investigation included a total of nine beam specimens, approximately 330 mm in diameter and 2.85 m in length, tested in three and four-point bending. Glass-FRP (GFRP) tubes with different wall thicknesses and proportions of fibres in the longitudinal and hoop directions were used in eight specimens. One control specimen was cut from a conventional prestressed spun-cast pole and tested for comparison. Also, one specimen was essentially a control CFFT. The main parameters studied were tube laminate structure, concrete wall thickness, and the effect of additional steel rebar in SCFTs. The experimental investigation also included six push-off stub specimens tested to examine the bond behaviour of SCFTs. An analytical model predicting the flexural response of SCFT beams was developed, verified, and used in a parametric study to examine a wider range of tube laminate structures, concrete wall thicknesses and FRP tube thicknesses. The study demonstrated the feasibility of fabrication of SCFTs in conventional precast plants. SCFTs were shown to have similar flexural strength to conventional prestressed spun-cast poles of an equivalent reinforcement index but are less stiff due to the lower modulus of FRP and lack of prestressing. SCFTs with inner-to-outer diameter ratio (Di/Do) up to about 0.6 achieved the same flexural strength as the CFFT specimen. However, the parametric study showed that this optimum (Di/Do) ratio is dependent on tube thickness and laminate structure and is generally smaller in thicker tubes or tubes stiffer in the longitudinal direction. / Thesis (Master, Civil Engineering) -- Queen's University, 2007-04-19 15:49:45.19

Fiber reinforced polymers (FRPs) are increasingly being accepted in structural engineering applications. One promising system involves the use of concrete-filled FRP tubes (CFFTs) as bridge piers, columns or piles. While CFFT members have been extensively studied under various loading conditions, very little attention has been given to their connections to other structural components such as footings and beams. This study explores two different moment connections for CFFT members, using 13 medium-scale specimens and seven ancillary tests. The first connection involves embedment of the FRP tube into the concrete foundations during casting. Five-219 mm diameter (D) precast CFFTs were embedded into 500x500x500 mm concrete foundation each, at different embedment lengths ranging from 0.3D to 1.5D and tested in flexure as cantilevers with 1100 mm spans. The study showed that the optimal embedment length was 0.73D. This was essentially the minimum embedment length necessary to produce tension failure of the CFFT member outside the footing, rather than premature bond failure that would otherwise occur at lower loads. Additionally, six push-through tests were conducted on CFFT stubs embedded into footings. The average bond strength was found to be 0.75 MPa. The second connection involved adhesive bonding of hollow FRP tubes to short reinforced concrete circular stubs protruding from concrete footings. The remainder of the tube was then filled with concrete, without the need for shoring. Four-169 mm diameter FRP tubes were first adhesively bonded onto footings with heavily steel-reinforced concrete stubs varying in length from 0.5D to 2.0D, and tested as cantilevers with 1300 mm spans. The optimal bond length that would lead to flexural failure of the tube just outside the stub, rather than bond failure, was about 1.1D. Based on this, two additional specimens with 1.5D stubs having varying steel reinforcement ratio (ρ) in the stubs were tested. It was shown that the optimal ρ was 2.5%. Finally, the effect of low cycle reversed bending fatigue was studied using two additional specimens, including one with a sustained axial load of 15-19% of the CFFT axial capacity. Remarkable levels of ductility associated with the plastic hinge forming in the stub were observed. / Thesis (Master, Civil Engineering) -- Queen's University, 2010-01-28 16:09:40.606

No description available.

Glass fibre-reinforced polymer (GFRP) tubular poles can be superior to conventional poles, in that they are lighter in weight and more durable. Thin-walled tubular poles, however, tend to fail in flexure by local buckling, before fully utilizing the high tensile strength of GFRP. Increasing the wall thickness would solve this problem, but at a significant material cost. A simple and economical solution is to partially fill the tube with concrete. The aim of this study is to establish the optimal length of concrete filling that is required to achieve the highest moment capacity at a minimum dead weight in cantilevered GFRP and steel poles. The study comprises experimental and numerical phases. Six 3660 mm long and 220 mm in diameter GFRP tubes of 4.15 mm wall thickness as well as four 1855 mm long and 114 mm in diameter steel tubes of 3 mm wall thickness, were filled with concrete of varying lengths, ranging from zero to a 100% of the span. The tubes were tested to failure in cantilever bending. The completely filled tubes achieved nearly double the strength of the hollow ones. Furthermore, it was found that the optimal ratio of concrete filling length was 0.34 and 0.46 of the span, for the GFRP and steel tubes, respectively. This is defined as the minimum filling length required to achieve the capacity of the completely filled tube. Numerical models have been developed to predict the behaviour of partially concrete-filled GFRP and steel tubes as well as the optimal filling ratio. The models incorporate other models developed for hollow and completely filled tubes and account for the slight non-linearity of multi-layer GFRP tubes, concrete, and steel plasticity. An important feature of the models is their ability to account for ovalization and local buckling of the hollow part of thin tube. The models were successfully validated and used in a parametric study to investigate the effects of key parameters, namely diameter-to-thickness (D/t) ratio, GFRP laminate structure and steel yield strength. It was shown that the optimal filling ratio increases as D/t ratio is reduced or as more GFRP fibres become oriented longitudinally. However, it was unaffected by the steel yield strength. / Thesis (Master, Civil Engineering) -- Queen's University, 2008-09-10 22:38:37.671

Fibre reinforced polymers (FRPs) are currently being used in new bridge construction as a feasible alternative material for corroded bridge deck replacements, footbridges, and emergency vehicle bridges. For both military and civilian applications, there exists a need for bridges that are lightweight and inexpensive, that can be readily transported and easily erected. The 10 m glass FRP deployable box beam presented in this thesis was developed to aid cross-country mobility in areas where infrastructure has been damaged by conflict or natural disasters. The box beam represents one trackway of a dual trackway system. The quasi-static and dynamic behaviour of the box beam was investigated under laboratory and field conditions. Quasi-static tests were conducted to ensure the strength of the steel hinge, the hinge connection to the base plate of the box beam, and the overall box beam would support the vehicle loads in field testing. Data from these tests were used to validate the finite element model. Field testing was conducted to investigate the natural frequencies of the box beam, calculate the dynamic increment of the structure, and confirm the validity of the finite element model created in Matlab. Three vehicles were used to evaluate the response of the box beam to different types of suspension, loads, and number of wheels per trackway. A finite element model was developed to predict the displacement of the bridge under various vehicle loads. The analysis resulted in displacement contours within a reasonable amount of error when compared to those measured in field testing. Recommendations for future research and development of the structure are provided based on this research. / Thesis (Master, Civil Engineering) -- Queen's University, 2008-09-26 22:49:59.077

In recent years, fibre reinforced polymer (FRP) materials have demonstrated enormous potential as materials for repairing and retrofitting concrete bridges that have deteriorated from factors such as electro-chemical corrosion and increased load requirements. However, concerns associated with fire remain an obstacle to applications of FRP materials in buildings and parking garages due to FRP’s sensitivity to high temperatures as compared with other structural materials and to limited knowledge on their thermal and mechanical behaviour in fire. This thesis presents results from an ongoing study on the fire performance of FRP materials, fire insulation materials and systems, and FRP wrapped reinforced concrete columns. The overall goal of the study is to understand the fire behaviour of FRP materials and FRP strengthened concrete columns and ultimately, provide rational fire safety design recommendations and guidelines for FRP strengthened concrete columns. A combined experimental and numerical investigation was conducted to achieve the goals of this research study. The experimental work consisted of both small-scale FRP material testing at elevated temperatures and full-scale fire tests on FRP strengthened columns. A numerical model was developed to simulate the behaviour of unwrapped reinforced concrete and FRP strengthened reinforced concrete square or rectangular columns in fire. After validating the numerical model against test data available in literature, it was determined that the numerical model can be used to analyze the behaviour of concrete axial compressive members in fire. Results from this study also demonstrated that although FRP materials experience considerable loss of their mechanical and bond properties at temperatures somewhat below the glass transition temperature of the resin matrix, externally-bonded FRP can be used in strengthening concrete structural members in buildings, if appropriate supplemental fire protection system is provided over the FRP strengthening system. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2009-12-17 14:11:27.931

Fibre reinforced polymer (FRP) materials have been a material of interest in the field of structural engineering due to their superior mechanical properties such as high strength to weight ratios and resistance to environmental degradation and corrosion. Even though research has established the material to be a viable option for construction they are highly susceptible to elevated temperatures. There are several systems available on the market and a great deal of research needs to be conducted to investigate the change in properties and different behaviour at elevated temperature to serve as a better basis for design. The main objective of this project and the experimental program presented in this thesis is to study the thermo mechanical properties of the available systems on the market. A summary of the previous research done in the area covering other materials is presented providing an introduction to the behaviour of different systems under elevated temperature. Then, two different experimental programs are presented. The first considers the glass transition temperature and thermal decomposition of the different systems and the second examines the tensile strength of the different systems under different temperature regimes. The results of both experimental programs are presented and then a connection between the thermo mechanical properties of the resins and the overall strength of the system is established. The research demonstrates that the glass transition temperature of the resin used for an FRP strengthening system is the main determinant of the performance at high temperatures. / Thesis (Master, Civil Engineering) -- Queen's University, 2011-06-16 09:21:32.228

Given the current global crisis of deteriorating infrastructure, structural rehabilitation has been the focus of much recent research in the field of civil engineering. Consequently, Fibre Reinforced Polymers (FRP’s) are becoming an increasingly common method for retrofitting deficient structures. However, skepticism regarding the structural performance of FRP’s during fire is preventing their widespread implementation in building applications. Because of the degradation of FRP material properties during heating, most current design codes completely neglect their structural contributions in fire design. The intention of this research thesis is to investigate the thermal and mechanical behaviour of insulated FRP retrofitted reinforced concrete structures at elevated temperatures. Two intermediate-scale reinforced concrete slabs were first strengthened with FRP and protected with spray-on insulation. Thermal results from fire testing of the slabs provided a basis on which to develop insulation schemes for larger specimens. These larger specimens consisted of two full-scale T-Beams and two full-scale columns, which were also strengthened with FRP and insulated. All of these specimens succeeded in obtaining four hour fire ratings upon fire testing. Though the FRP strengthening systems were compromised quickly during heating, the insulation provided sufficient protection to the T-beams and columns for them to resist the applied service loads throughout the duration of fire exposure. Detailed calculations were also conducted using thermal data from the full-scale specimen fire tests in order to predict the change in capacity of these structures with time. This thesis shows that, with careful considerations towards insulation and anchorage design, FRP-strengthened reinforced concrete structures are able to obtain fire ratings in excess of four hours. / Thesis (Master, Civil Engineering) -- Queen's University, 2012-05-29 15:46:00.801

This thesis investigates the shear capacity of concrete T-beams prestressed with CFRP cables (CFCC) and contributes to the scarce research available for shear behavior of FRP prestressed concrete beams. Four beams are tested under distributed load, while twelve beams are tested under four point bending. Three different a/d ratios of 1.5, 2.5 and 3.5 are investigated. The results show that the shear capacity of the beams increases significantly when a/d is reduced below 2.5. The effect of FRP stirrups on the shear capacity of the beams is investigated and it is shown that the minimum required stirrups according to CSA-S6-10 are ineffective in deep beams with a/d = 1.5. The accuracy of current North American shear design formulas for FRP prestressed concrete beams subjected to four-point bending and distributed load is evaluated. The available strut and tie models are studied for determining the shear capacity of FRP prestressed deep beams.

This thesis investigates the shear capacity of concrete T-beams prestressed with CFRP cables (CFCC) and contributes to the scarce research available for shear behavior of FRP prestressed concrete beams. Four beams are tested under distributed load, while twelve beams are tested under four point bending. Three different a/d ratios of 1.5, 2.5 and 3.5 are investigated. The results show that the shear capacity of the beams increases significantly when a/d is reduced below 2.5. The effect of FRP stirrups on the shear capacity of the beams is investigated and it is shown that the minimum required stirrups according to CSA-S6-10 are ineffective in deep beams with a/d = 1.5. The accuracy of current North American shear design formulas for FRP prestressed concrete beams subjected to four-point bending and distributed load is evaluated. The available strut and tie models are studied for determining the shear capacity of FRP prestressed deep beams.