The research program involved both numerical and experimental work. The numerical analysis was conducted to simulate the static and dynamic behaviour of the 81 m meteorological FRP guyed tower under wind and ice loading. The FRP tower consisted of 16 segments each made of 3 cells connected together to form an equilateral triangle having equal sides of 450 mm. The segments were interconnected using internal sleeves. Various non-linear finite element models were developed to study a number of design parameters for the 81 m FRP tower such as, different laminates containing a variety of stacking sequences of laminate orientations with various thicknesses, different cable diameters, and appropriate guy cable spacing levels. The effect of pre-stressing the guy cables up to 10 % of their breaking strength was investigated. The effect of fibre volume fraction on the design of the FRP tower was also examined. Furthermore, an 8.6 m FRP tower segment was designed using the finite element analysis and subject to the same loading conditions experienced by the bottom section of the 81 m FRP tower. A modal analysis was carried out for both the 8.6 m FRP tower segment with and without a mass on the top as well as for the 81 m FRP guyed tower to evaluate the vibration performance of these towers. The experimental work involved extensive material testing to define the material properties for use in the analysis of the 81 m FRP tower. It also involved the design and fabrication of a special collapsible mandrel for fabricating the FRP cells for the 8.6 m tower segment. The 8.6 m tower was tested horizontally under static lateral loading to 80 % of its estimated failure load using a “whiffle tree” arrangement, in order to simulate a uniformly distributed wind loading. Later, the same FRP tower was erected in a vertical position and was tested with and without a mass on top under dynamic loading to obtain the natural frequencies. Lastly, a comparative study was conducted between two 81 m FRP towers having different fibre volume fractions and a steel tower having a circular cross section.

The behavior of concrete members reinforced with fiber reinforced polymer (FRP) bars has been the focus of many studies in recent years. Nowadays, several codes and design guidelines are available for the design of concrete structures reinforced with FRP bars under flexural and shear loads. Meanwhile, limited research work has been conducted to examine the axial behavior of reinforced concrete (RC) columns with FRP bars. Due to a lack of research investigating the axial behavior of FRP reinforced concrete columns, North American codes and design guidelines do not recommend using FRP bars as longitudinal reinforcement in columns to resist compressive stresses. This dissertation aims at evaluating the axial performance of RC compression members reinforced with glass FRP (GFRP) and carbon FRP (CFRP) bars and stirrups through experimental and analytical investigations. A total of twenty seven full scale circular RC specimens were fabricated and tested experimentally under concentric axial load. The 300 mm diameter columns were designed according to CAN/CSA S806-12 code requirements. The specimens were divided to three series; series I contains three reference columns; one plain concrete and 2 specimens reinforced with steel reinforcement. Series II contains 12 specimens internally reinforced with GFRP longitudinal bars and transverse GFRP stirrups, while series III includes specimens totally reinforced with CFRP reinforcement. The experimental tests were performed at the structural laboratory, Faculty of Engineering, University of Sherbrooke. The main objective of testing these specimens is to investigate the behavior of circular concrete columns reinforced with GFRP or CFRP longitudinal bars and transverse hoops or spirals reinforcement. Several parameters have been studied; type of reinforcement, longitudinal reinforcement ratio, the volumetric ratios, diameters, and spacing of spiral reinforcement, confinement configuration (spirals versus hoops), and lap length of hoops. The test results of the tested columns were presented and discussed in terms of axial load capacity, mode of failure, concrete, longitudinal, and transverse strains, ductility, load/stress-strain response, and concrete confinement strength through four journal papers presented in this dissertation. Based on the findings of experimental investigation, the GFRP and CFRP RC columns behaved similar to the columns reinforced with steel. It was found that, FRP bars were effective in resisting compression until after crushing of concrete, and contributed on average 8% and 13% of column capacity for GFRP and CFRP RC specimens, respectively. Also, the use of GFRP and CFRP spirals or hoops according to the provisions of CSA S806-12 yielded sufficient restraint against the buckling of the longitudinal FRP bars and provided good confinement of the concrete core in the post-peak stages. The axial deformability (ductility) and confinement efficiency can be better improved by using small FRP spirals with closer spacing rather than larger diameters with greater spacing. It was found that, ignoring the contribution of FRP longitudinal bars in the CAN/CSA S806-12 design equation underestimated the maximum capacity of the tested specimens. Based on this finding, the design equation is modified to accurately predict the ultimate load capacities of FRP RC columns. New factors ?[indice inférieur g] and ?[indice inférieur c] were introduced in the modified equation to account for the GFRP and CFRP bars compressive strength properties as a function in their ultimate tensile strength. On the other hand, proposed equations and confinement model were presented to predict the axial stress-strain behavior of FRP RC columns confined by FRP spirals or hoops. The model takes into account the effect of many parameters such as; type of reinforcement, longitudinal reinforcement ratio; transverse reinforcement configuration; and the volumetric ratio. The proposed model can be used to evaluate the confining pressure, confined concrete core stress, corresponding concrete strain, and stress-strain relationship. The results of analysis using the proposed confinement model were compared with experimental database of twenty four full-scale circular FRP RC columns. A good agreement has been obtained between the analytical and experimental results. Proposed equations to predict both strength and stress-strain behavior of confined columns by FRP reinforcements demonstrate good correlation with test data obtained from full-scale specimens.

The research program involved both numerical and experimental work. The numerical analysis was conducted to simulate the static and dynamic behaviour of the 81 m meteorological FRP guyed tower under wind and ice loading. The FRP tower consisted of 16 segments each made of 3 cells connected together to form an equilateral triangle having equal sides of 450 mm. The segments were interconnected using internal sleeves. Various non-linear finite element models were developed to study a number of design parameters for the 81 m FRP tower such as, different laminates containing a variety of stacking sequences of laminate orientations with various thicknesses, different cable diameters, and appropriate guy cable spacing levels. The effect of pre-stressing the guy cables up to 10 % of their breaking strength was investigated. The effect of fibre volume fraction on the design of the FRP tower was also examined. Furthermore, an 8.6 m FRP tower segment was designed using the finite element analysis and subject to the same loading conditions experienced by the bottom section of the 81 m FRP tower. A modal analysis was carried out for both the 8.6 m FRP tower segment with and without a mass on the top as well as for the 81 m FRP guyed tower to evaluate the vibration performance of these towers. The experimental work involved extensive material testing to define the material properties for use in the analysis of the 81 m FRP tower. It also involved the design and fabrication of a special collapsible mandrel for fabricating the FRP cells for the 8.6 m tower segment. The 8.6 m tower was tested horizontally under static lateral loading to 80 % of its estimated failure load using a “whiffle tree” arrangement, in order to simulate a uniformly distributed wind loading. Later, the same FRP tower was erected in a vertical position and was tested with and without a mass on top under dynamic loading to obtain the natural frequencies. Lastly, a comparative study was conducted between two 81 m FRP towers having different fibre volume fractions and a steel tower having a circular cross section.

All reinforced concrete (RC) design theories are based on the assumption that concrete exhibits a perfect bond with the steel reinforcement. The bond between steel and concrete is essential to the transfer of the load applied from the concrete to the steel reinforcement. When steel bars are corroded, the concrete cracks, and the strength of the bond between the steel bars and the concrete is decreased. Structures such as bridges and marine structures are prone to corrosion. These structures are usually also subjected to repeated loading. Repeated loading can initiate cracks in the concrete surrounding the steel bars that propagate as the number of load cycles increases leading to the destruction of the concrete-steel interface and slip of the steel bars inside the concrete. The combined effect of corrosion and repeated loading reduces the service life of RC structures. This study investigated the effect of anchorage length and confinement from supports, stirrups and carbon fibre reinforced polymer (CFRP) on the bond behaviour of corroded and uncorroded reinforced concrete beams subjected to monotonic and repeated loading. Fifty-seven large-scale reinforced concrete beams (152*254*2000 mm) were tested for the purpose of this study. The variables were stirrup spacing (75 mm and 150 mm), anchorage length (200 mm, 350 mm and 650 mm), corrosion level (mild corrosion and high corrosion level), repair condition (wrapped or unwrapped with FRP sheets in the anchorage zone) and the fatigue load range. From this study, it was found that the resistance to bond stresses (forces) between the steel and concrete were provided mainly by the concrete keys. The bond stresses increased with the number of the concrete keys engaged. The factors that affected the number of concrete keys engaged were: confinement from the supports, confinement from the stirrups, confinement due to wrapping with FRP sheets and change in anchorage length. Decreasing the stirrup spacing from 150 mm to 75 mm increased the number of concrete keys engaged thus increasing the bond capacity and changed the mode of failure under monotonic loading from splitting to pullout. The beams with the first stirrup spacing (150 mm c/c) when tested under repeated loading failed by bond fatigue while the beams with the second stirrup spacing (75 mm c/c) failed by flexure at the end of a debonded region that started from the support. The failure mechanism is discussed for each case. The change in anchorage length from 200 mm to 350 mm increased the static and fatigue bond capacity of the beams by 60% and 12.5% respectively. The debonding for this group of beams (200 mm and 350 mm anchorage length) subjected to monotonic loading started from the pocket and propagated towards the support while the debonding for the 350 mm anchorage length beams subjected to repeated loading started at the location of a crack that widened while fatiguing the beam and propagated towards the support. The change in anchorage length from 350 mm to 650 mm did not affect the monotonic bond capacity of the beams since in this case, debonding was initiated from the supports and the change in anchorage length had little effect. The confinement with FRP sheets caused the concrete keys at both the top and bottom of the bar to be crushed and increased the bond stress of the wrapped beams. The bond strength of the beams repaired with CFRP sheet was governed by the strength of the FRP sheets for all anchorage lengths and corrosion levels. The CFRP repair of the 200 mm anchorage length set of beams increased the capacity of the uncorroded beams by 80% and the capacity of the corroded beams by about 25% under static and repeated loading compared to the control (uncorroded and unrepaired) beam. The CFRP repair of the 350 mm anchorage length set of beams changed the mode of failure from bond to flexure. The fatigue life for the beams varied linearly on a logarithmic scale with the load range applied with a shallow slope. Corroding the 200 mm anchorage length set of beams to a mild corrosion level decreased their fatigue strength by 34% compared to the control beams. Corroding the 350 mm anchorage length set of beams to a mild corrosion level did not affect the fatigue strength for the single beam that failed in bond. Finally a probabilistic approach was used to allow the design engineers to estimate the design fatigue life for similar beams with 95% probability for a given normalized stress ratio.

The use of fiber-reinforced polymer (FRP) composites as a repair and strengthening material for reinforced concrete (RC) members has increased over the past twenty years. The tendency for FRP sheets to debond at loads below their ultimate capacity has prompted researchers to investigate various approaches and designs to increase the efficiency of FRP strengthening systems. Various anchors, wrapping techniques and clamps have been explored to postpone and/or delay the debonding process which results in premature failure. FRP anchors are of particular interest because they can be selected to have the same material properties as the FRP sheets that are installed for strengthening or repair of the RC member and can be done so using the same adhesives and installation techniques. This research study aimed to investigate the effectiveness of using commercially manufactured FRP anchors to secure FRP sheets installed to strengthen and repair RC beams in shear and RC slabs in flexure. Twenty one shear critical RC beams were strengthened in shear with u-wrapped FRP sheets and FRP anchors. Eight RC one-way slabs were strengthened in flexure with FRP sheets and FRP anchors. The test variables include the type of FRP sheets (GFRP,CFRP), type of FRP anchors (CFRP, GFRP) and the strengthening configuration. The test results of the shear critical RC beams revealed that the installation of commercially manufactured FRP anchors to secure externally applied u-wrap FRP sheets improved the shear behaviour of the strengthened beam. The installation of FRP anchors to secure u-wrapped FRP sheets provided an average 15% increase in the shear strength over companion unanchored beams and improved the ductility of failure experienced with the typical shear failure in beams. The use of FRP anchors allowed the FRP sheets to develop their tensile capacity. Premature failure by FRP debonding was eradicated with the presence of FRP anchors and the failure modes of the strengthened beams with FRP anchors was altered when compared to the companion unanchored beam. Additionally, as the width of a u-wrapped FRP sheet was increased; larger increases in strength were obtained when FRP anchors were used. The test results of the flexure critical RC slabs revealed that the installation of commercially manufactured FRP anchors to secure externally applied u-wrapped FRP sheets improved the behaviour of strengthened slabs. Installation of FRP anchors to secure flexural FRP sheets provided an average 17% increase in strength over companion unanchored beams. The use of FRP anchors allowed the FRP sheets to develop their full tensile strength. Premature failure by CFRP debonding was not eliminated with the presence of FRP anchors; rather the critical failure zone was shifted from the bottom soffit of the slab to the concrete/steel rebar interface. The failure modes of slabs with FRP anchors were altered for all specimens when compared to the companion unanchored slab. The effective strain in the FRP sheet was predicted and compared with the experimental results. The efficiency of FRP anchors defined as the ratio of effective strain in the FRP sheet with and without anchors was related to the increase in strength in beams and slabs. A good correlation was established between the FRP anchor efficiency and the increase in strength. A step-by-step FRP anchor installation procedure was developed and a model to predict the number of FRP anchors required to secure a FRP sheet was proposed. This is the most comprehensive examination of beams and slabs strengthened with FRP sheets and FRP anchors conducted to date. This study provides an engineer with basic understanding of the mechanics, behaviour and failure modes of beams and slabs strengthened with FRP sheets and anchors.

The use of Fibre Reinforced Polymers (FRP) has grown in popularity in the construction industry. FRP has proven useful in the retrofit of various types of structural elements. It may be used for the strengthening of beams, the seismic upgrade of walls panels, as well as the jacketing of columns to provide confinement. There exist several methods of FRP application for the case of structural retrofits. These include the application of pre-prepared FRP mats, or application of FRP via the wet lay-up process. However, a new technique developed at the University of British Columbia allows for the application of FRP in the form of a spray. Externally bonded Sprayed FRP (SFRP) is known to increase strength and energy absorption capacity of a retrofitted member as well as, or better than, FRP sheets. However, tests have primarily been carried out on concrete members only. An area of interest, into which not much research has been conducted, is the application of SFRP to timber. Timber bridges are extensively used in many parts of the world. Often due to remoteness and practical constraints, it is impossible to apply FRP sheets to retrofit these bridges. SFRP would be a much easier method of FRP application. This study looked at the application of SFRP to Douglas Fir (D.Fir) Beam specimens subjected to 3-Point Flexural Loading only. The specimens were treated with either a water based (Borocol) or oil borne (Creosote) antifungal preservative prior to being sprayed with FRP. Different combinations of adhesives/bonding agents including Hydroxymethylated Resorcinol and Polymeric Isocyanates were used to try to develop a strong bond. When considering using only chemical adhesives to obtain a proper bond between the two constituents of the composite, use of HMR is recommended for timber which is untreated or has been treated with a water borne preservative such as Borocol, while a pMDI adhesive such as AtPrime 2 is recommended for timber treated with an oil borne preservative such as Creosote. For Non Creosoted beams, adhesives did not generate as significant of a strength gain. For Creosoted beams, adhesives may be sufficient to generate significant strength gain when SFRP is applied to a beam. Considering that most structures in use would probably have been treated with a preservative similar to Creosote, in practice, AtPrime 2 or some other some sort of pMDI would probably be the adhesive of choice. Based on the results of the study, it is possible to say that the application of SFRP to retrofit/rehabilitate timber structures shows considerable promise. If a decent bond is achieved between the composite constituents, it is possible to substantially increase the ultimate flexural strength of the member, as well as drastically increase its ductility and energy absorption capacity. It is recommended that further tests be carried out using different types of loading schemes, geometrical configurations of SFRP, other types of anchorage, and development of a proper analytical model before the method is adopted for widespread use.

This thesis discusses the development of a new type of fibre-reinforced polymer (FRP) beam for use in civil engineering systems. After a detailed evaluation of the advantages and disadvantages of current FRP beam technology, a different approach is proposed which combines traditional laminates with a novel casting technique. To pre-dimension the beam, the classical beam theory is adapted to allow for FRP materials. The resulting formulae were used to determine critical parameters, such as laminate thickness and location in the cross-section, and core dimensions, and to identify failure modes. Based on the results of this analytical study, a detailed testing program was developed. In addition to classical tests, such as bending, shear, and lateral torsion, the performance of the beam was also examined under particular loading regimes specifically designed to induce local failure modes, such as buckling of the web and bearing failure of the section under concentrated loads. The experimental results revealed very good agreement with the analytical predictions. These results were corroborated by a detailed non-linear finite-element analysis, including core cracking and laminate damage. This analysis, in particular, highlighted the synergy between bending and shear behaviour of the beam. This study has revealed that this new type of FRP beam behaves in a predictable manner. Furthermore, the experimental results verified that the cross-section, which combines traditional laminates with cast polymer concrete, did not suffer from many of the disadvantages identified in current FRP beams. The cracking of the polymer concrete under shear, however, does cause the beam to fail prior to the laminates reaching their ultimate shear stress.

The use of Fibre Reinforced Polymers (FRP) has grown in popularity in the construction industry. FRP has proven useful in the retrofit of various types of structural elements. It may be used for the strengthening of beams, the seismic upgrade of walls panels, as well as the jacketing of columns to provide confinement. There exist several methods of FRP application for the case of structural retrofits. These include the application of pre-prepared FRP mats, or application of FRP via the wet lay-up process. However, a new technique developed at the University of British Columbia allows for the application of FRP in the form of a spray. Externally bonded Sprayed FRP (SFRP) is known to increase strength and energy absorption capacity of a retrofitted member as well as, or better than, FRP sheets. However, tests have primarily been carried out on concrete members only. An area of interest, into which not much research has been conducted, is the application of SFRP to timber. Timber bridges are extensively used in many parts of the world. Often due to remoteness and practical constraints, it is impossible to apply FRP sheets to retrofit these bridges. SFRP would be a much easier method of FRP application. This study looked at the application of SFRP to Douglas Fir (D.Fir) Beam specimens subjected to 3-Point Flexural Loading only. The specimens were treated with either a water based (Borocol) or oil borne (Creosote) antifungal preservative prior to being sprayed with FRP. Different combinations of adhesives/bonding agents including Hydroxymethylated Resorcinol and Polymeric Isocyanates were used to try to develop a strong bond. When considering using only chemical adhesives to obtain a proper bond between the two constituents of the composite, use of HMR is recommended for timber which is untreated or has been treated with a water borne preservative such as Borocol, while a pMDI adhesive such as AtPrime 2 is recommended for timber treated with an oil borne preservative such as Creosote. For Non Creosoted beams, adhesives did not generate as significant of a strength gain. For Creosoted beams, adhesives may be sufficient to generate significant strength gain when SFRP is applied to a beam. Considering that most structures in use would probably have been treated with a preservative similar to Creosote, in practice, AtPrime 2 or some other some sort of pMDI would probably be the adhesive of choice. Based on the results of the study, it is possible to say that the application of SFRP to retrofit/rehabilitate timber structures shows considerable promise. If a decent bond is achieved between the composite constituents, it is possible to substantially increase the ultimate flexural strength of the member, as well as drastically increase its ductility and energy absorption capacity. It is recommended that further tests be carried out using different types of loading schemes, geometrical configurations of SFRP, other types of anchorage, and development of a proper analytical model before the method is adopted for widespread use. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

The mechanical properties of the polymer-modified mortar are markedly improved over conventional cement mortar. We utilized recycled ABS in powder form and a polymer latex emulsion, polymer percentage ranges from 0 to 25 percent by polymer/cement ratio were investigated. The mechanical properties investigated were compression strength and adhesion strength. Compression strength effects did not have an impact on adhesion strength. Adhesion strength was calculated with pullout testing apparatus designed by the author. Results indicate that recycled ABS had a lower adhesive strength than the acrylic latex emulsion and the base mortar, but did increase in adhesive strength when mixed with maleic-anhydride. The adhesive strength was investigated for a Fiber Reinforced Polymer (FRP) made of an "E" glass fiber that is a continuous strand roving oriented and pre-tensioned longitudinally in an isopthalic polyester matrix material. The FRP rebar was compared to standard steel rebars, and found that the standard steel corrugated rebar had a higher adhesive strength, due to mechanical interlocking. This was clarified by measurements using a smooth steel rebar. Characterization of the polymer-modified mortar was conducted by pore analysis and scanning electron microscopy. Scanning Electron Microscopy was implemented to view the polymer particles, the cement fibrils formed by the hydration, and to prove Ohama's theory of network structure.

This thesis details a study of the structural behavior of Hybrid-Composite Beams (HCB) consisting of a fiber reinforced polymer (FRP) shell with a concrete arch tied with steel prestressing strands.  The HCB offers advantages in life cycle costs through reduced transportation weight and increased corrosion resistance. By better understanding the system behavior, the proportion of load in each component can be determined, and each component can be designed for the appropriate forces. A long term outcome of this research will be a general structural analysis framework that can be used by DOTs to design HCBs as rapidly constructible bridge components. This study focuses on identifying the load paths and load sharing between the arch and FRP shell. Testing was performed by applying point loads on simple span beams (before placing the bridge deck) and a three beam skewed composite bridge system.  Curvature from strain data is used to find internal bending forces, and the proportion of load within the arch is found. Additionally, a stress integration method is used to confirm the internal force contributions.  The tied arch carries about 80% of the total load for the non-composite case without a bridge deck.  When composite with a bridge deck, the arch has a minimal contribution to the HCB stiffness and strength as it is below the neutral axis. For this composite case the FRP shell and prestressing strands resist about 85% of the applied load while the bridge deck carries the remaining 15% to the end diaphragms and bearings. / Master of Science