Dissertação apresentada para obtenção do grau de Mestre em Estruturas de Engenharia Civil, na Faculdade de Engenharia da Universidade do Porto, sob a orientação do Professor Joaquim Figueiras

Tese de mestrado integrado. Engenharia Civil (Especialização em Materiais e Processos de Construção). Faculdade de Engenharia. Universidade do Porto. 2009

Researchers and practitioners have developed new treatment options for chronic pain management based on biopsychosocial models of pain known as interdisciplinary pain management programs (IPMP), which involve interdisciplinary care that integrates physical treatment with emotional, environmental, behavioral, and cognitive interventions. Despite literature documenting the effectiveness of IPMPs, patients find it difficult to obtain authorization for these programs from third party insurance payers. The purpose of this quantitative causal comparative study was to explore whether a patient's perceived quality of life after injury but prior to treatment will affect his or her success in an IPMP. This study was based in the theoretical foundations of the biopsychosocial model of pain as well as positive psychology. Regression analysis and a test of mean differences were used to analyze the data to determine if there was a statistically significant difference in the perceived success in an IPMP program between patients who were part of a workers' compensation program (n = 77) and those who were not (n = 60). None of the null hypotheses could be rejected. Quality of Life Index (QOLI) scores were not predictive of success in an IPMP. None of the QOLI 16 subscales were predictive of success in an IPMP. Additionally, there was no significant difference between patients who were on workers' compensation and those who were not. This study contributes to the knowledge gap regarding appropriate screening tools for admittance into an IPMP. The results of this study can be used by practitioners who are trying to get patients approved for an IPMP and by third party insurance payer when determining which patients would most benefit from attending an IPMP.

Innovative new flooring systems utilising lightweight fibre reinforced polymer composite materials may have the significant potential to offer both economic and performance benefits for infrastructure asset owners compared to conventional concrete and steel systems. Over recent years, a range of prototype floor systems using fibre reinforced polymer composites have been developed by researchers at the University of Southern Queensland. However before such structural systems can be widely adopted by industries, fundamental understanding of their behaviour must be improved. Such work will allow for the development of new design and analysis procedures which will enable engineers to efficiently and accurately design and analyse such structures. This dissertation presents an investigation into a new two-way fibre reinforced composite floor slab system. The proposed new two-way slab system is, in essence, a sandwich structure with an innovative hollow core made from a castable particulate filled resin system. The key focus of this dissertation is the development of a new analysis tool to analyse the two-way fibre reinforced composite slab and facilitate subsequent parametric studies into slab configurations for concept refinement. The detailed 3D finite element analyses and experimental investigations are performed to verify the new analysis tool, and provide more detailed insight into the structural behaviour of this new two-way fibre reinforced composite slab. Comparisons with detailed 3D FEA and experiments illustrate that the simplified analysis tool is capable of providing sufficient accuracy for the preliminary analysis of a slab structure. Moreover, the 3D finite element analyses agree well with the experiments, and it is concluded that the behavioural responses of the proposed new slab structure can be reliably predicted. The experimental results show that this new slab concept exhibits quite a robust static behaviour and is likely to have a robust fatigue performance.

Recently, the use of Mechanically Fastened Fiber-Reinforced Polymer (MF-FRP) systems has emerged as a viable means for flexural strengthening of reinforced concrete members. The technique is suitable for emergency repairs where constructability and speed of installation are critical requirements. The MF-FRP system consists of pre-cured FRP laminates with enhanced longitudinal bearing strength that are attached to the concrete substrate by means of mechanical steel anchors. This research project presents an experimental investigation comprising a series of flexural tests on scaled one-way RC slabs. The test matrix includes MF-FRP strengthened specimens, a counterpart with the externally bonded (EB) FRP reinforcement, and a control specimen. The effects of fastener layout and laminate length on strength increase and failure mode were studied. It is shown that with proper selection of fastener layout the MF-FRP system results in a significant deformability and strength increase, where the latter is comparable to that attained using EB-FRP sheets. Specific gaps on the existing analytical procedures for flexural strengthening with MF-FRP systems are finally discussed.

Reinforced Concrete (RC) bridge piers, RC columns along exterior of buildings or those located in parking garages are designed to support large compressive axial loads but are vulnerable to transverse out-of-plane loadings, such as those arising from impacts or explosions. To address a lack of understanding regarding blast and impact response of RC members and the need for retrofit techniques to address deficiencies in existing structures, a multi-disciplinary team including various institutes of the National Research Council and the University of Ottawa has initiated work towards developing a fibre reinforced polymer composite protection system for RC columns subjected to extreme shocks. This thesis will focus on the impact program of the aforementioned project. An extensive literature review was conducted to gain a better understanding of: impact loading and associated dynamic effects; experimental testing of RC members subjected to impact; experimental testing of axially loaded members; and retrofit methods for the protection of RC under impact loading. Five half-scale RC columns were constructed and tested using a drop-weight impact machine and two additional specimens were tested under static loading. Deflections, strain distributions within the columns, impact loads and reaction loads were measured during the testing of the built RC members. Comparisons of experimental datum were established between members with differing levels of axial load and between a retrofitted and a non-retrofitted member. Single-degree-of-freedom analysis was used to obtain the predicted response of certain columns under impact loading allowing for comparisons with experimental data.

Over the life span of a structure it may become necessary to retrofit, or strengthen certain components or elements. This may be due to construction errors, changes in use and occupancy, or changes due to material deterioration or damage. Slab-column connections in flat slab structures might need to be strengthened for punching shear. Using steel shear bolts to strengthen connections for punching shear is a new technique used for retrofit that was developed at the University of Waterloo. If the retrofitted part of the structure is exposed to the atmosphere, or to chemicals such as deicing salts, the steel can corrode, thus furthering to damage the structure. Non-corrosive materials that can replace the steel shear bolts can be a good practical alternative to steel. Reported in this thesis are the results of research on the development and use of non-corrosive shear bolts for reinforced concrete interior slab-column connections. Externally applied shear reinforcing bolts provide the punching shear reinforcement strength, while allowing the flexibility and ease of installation of an external application after construction. By providing a bearing area against both sides of the slab surface, the formation of punching shear cracks can be restrained, and the connection can become strengthened against punching shear failure. Three different types of non-corrosive shear bolts were developed and tested. The first was an off-the-shelf glass fiber reinforced polymer (GFRP) bolt / nut product. The two others used two different GFRP core rods with aluminum fittings crimped to their ends. A total of six specimens were tested, four were tested under an increasing static load, while two were tested with an unbalanced pseudo-dynamic lateral load. All six specimens were designed to fail in punching shear before reaching their flexural capacity. The results are compared against previous test results of specimens both unreinforced and reinforced with steel shear bolts to determine their effectiveness. From the test results it was found that the GFRP shear bolts did strengthen the connections for punching shear. The GFRP nut and bolt did not strengthen the connection, and, in fact, decreased its overall strength when compared to the unreinforced specimen. The presence of the GFRP shear bolts also increased the connection ductility and the deflection capability. In the pseudo-dynamic tests the GFRP shear bolts significantly increased the amount of energy dissipated by the connection under reverse cyclic loading. The results of the testing appeared to be depended on the proper application of the crimping technique to place the bolts in the slab.

Nowadays, timber is widely used in construction industry thanks to its availability and good properties. The use of solid (sawn) timber is not always proper since it is only available up to certain dimensions. Therefore, the so-called Engineered WoodProducts (EWPs) have been introduced to cope with the different design needs of structures. The Glued laminated Timber (glulam) is a type of EWPs that consists of smallsections of timber laminates glued together to form beams and columns. Glulam can be manufactured in almost any size and shape; it can also be tapered or notched. However, notching a beam at its end leads to a stress concentration at the re-entrantcorner of the notch due to the sudden change in the notched beam’s cross section. The concentration of shear and tensile stresses perpendicular to the grain can lead to a catastrophic brittle failure caused by the crack propagation from the notch corner. Crack opening due to tensile stresses perpendicular to grain is the most common failure at the notch corner and it is always taken into design consideration. However,shear component is usually exists and must be also considered in design to guarantee the safety of the structure. Currently, only the normal forces perpendicular to the beam’s axis are considered in the design of the reinforcement in design handbooks. The aim of this thesis was to study the structural behavior of notched glulam beams reinforced by adhered plywood panels and FRP. The carrying capacity of the notched glulam beams at their ends is the main subject of this thesis. In addition, a review of the notched beams design, reinforcements, and analysis theories are included. Experimental series of three point bending tests with notched glulam beams withdifferent configurations of reinforcement was carried out in lab. Deformations and forces were measured both with conventional techniques and with contact-free measurement systems - ARAMIS. On the other hand, a simple model of two dimensional plane stress element has been created of the unreinforced notchedbeam in ABAQUS. The normal and shear stresses were calculated for a horizontalpath of 100 mm in length starting from the notch tip. Afterwards, the mean stresseswere determined for the same path and have been used in calculations. The Mean Stress Approach has been adopted in the hand calculations to calculate the crack length and the failure load according to the ABAQUS model. Accordingly, the failure load was about 40 kN for the unreinforced beams. Also, Eurocode 5 has been used to calculate the failure load which gave a value of 20.2 kN for the unreinforced beams. The average maximum applied load in tests was 30 kN for the unreinforced beams while it reached about two and a half times this value for the CF-reinforced and the plywood-reinforced beams. / Tack vare sina goda egenskaper används trä i byggnadskonstruktioner i allt storeomfattning. Konstruktionsvirke (sågade trävaror) kan dock inte alltid användas pågrund av de begränsade dimensioner som finns tillgängliga. På grund av bl a dettahar ett flertal så kallade engineer wood products (EWP) utvecklats. Limträ är en typav EWP som består av sammanlimmade lameller som bygger upp tvärsnitt i balkareller pelare. Limträ kan tillverkas i nästan godtycklig storlek och form och kan enkeltförses med t ex urtag. Vid urtag i balkändar nära upplag uppstår högaspänningskoncentrationer vid urtagets horn på grund av geometrin. Koncentrationenav normalspänningar och skjuvspänningar kan leda till plötsligt brott på grund avsprickpropagering från urtagets hörn, något som måste tas hänsyn till viddimensionering. Dagens dimensioneringsmetoder är baserade på att man tar hänsyntill enbart normalspänningarna vinkelrät fiberriktningen.Målet med detta arbete har varit att studera beteendet hos limträbalkar med urtag vidupplag som förstärkts med fiberarmering eller plywood. Huvudmålet har varit attbestämma balkarnas bärförmåga, vilket skett genom att genomföra försök med olikakonfigurationer vad gäller förstärkningsmaterial och dess utformning. Vidare harolika dimensioneringsmetoder från litteraturen studerats.Kraft och förskjutning under provningarna uppmättes dels med traditionellamätmetoder, men deformationerna mättes även med beröringsfri metod, ARAMIS.En enkel tvådimensionell finit elementmodell skapades och analyserades i ABAQUSför analys av oförstärkt balk. Normalspänningar och skjuvspänningar beräknades ochmedelspänningarna längs en på förhand definierad sträcka beräknades.Medelspänningskriteriet användes sedan för att uppskatta balkens bärförmåga.Enligt FE-beräkningarna uppskattades bärförmågan för de oförstärkta balkarna till ca40 kN. Provningarna gav ett medelvärde på balkarnas bärförmåga på ca 30 kN,medan de förstärkta balkarna hade en 2,5 gånger högre bärförmåga. Skillnadenmellan FE-beräkningarna och provningarna kan förklaras med den osäkerhet somfinns vad gäller det aktuella trämaterialets egenskaper.Beräkningar enligt Eurokod 5 gav en karakteristisk bärförmåga på 20,2 kN.

Over the life span of a structure it may become necessary to retrofit, or strengthen certain components or elements. This may be due to construction errors, changes in use and occupancy, or changes due to material deterioration or damage. Slab-column connections in flat slab structures might need to be strengthened for punching shear. Using steel shear bolts to strengthen connections for punching shear is a new technique used for retrofit that was developed at the University of Waterloo. If the retrofitted part of the structure is exposed to the atmosphere, or to chemicals such as deicing salts, the steel can corrode, thus furthering to damage the structure. Non-corrosive materials that can replace the steel shear bolts can be a good practical alternative to steel. Reported in this thesis are the results of research on the development and use of non-corrosive shear bolts for reinforced concrete interior slab-column connections. Externally applied shear reinforcing bolts provide the punching shear reinforcement strength, while allowing the flexibility and ease of installation of an external application after construction. By providing a bearing area against both sides of the slab surface, the formation of punching shear cracks can be restrained, and the connection can become strengthened against punching shear failure. Three different types of non-corrosive shear bolts were developed and tested. The first was an off-the-shelf glass fiber reinforced polymer (GFRP) bolt / nut product. The two others used two different GFRP core rods with aluminum fittings crimped to their ends. A total of six specimens were tested, four were tested under an increasing static load, while two were tested with an unbalanced pseudo-dynamic lateral load. All six specimens were designed to fail in punching shear before reaching their flexural capacity. The results are compared against previous test results of specimens both unreinforced and reinforced with steel shear bolts to determine their effectiveness. From the test results it was found that the GFRP shear bolts did strengthen the connections for punching shear. The GFRP nut and bolt did not strengthen the connection, and, in fact, decreased its overall strength when compared to the unreinforced specimen. The presence of the GFRP shear bolts also increased the connection ductility and the deflection capability. In the pseudo-dynamic tests the GFRP shear bolts significantly increased the amount of energy dissipated by the connection under reverse cyclic loading. The results of the testing appeared to be depended on the proper application of the crimping technique to place the bolts in the slab.

Researchers and practitioners have developed new treatment options for chronic pain management based on biopsychosocial models of pain known as interdisciplinary pain management programs (IPMP), which involve interdisciplinary care that integrates physical treatment with emotional, environmental, behavioral, and cognitive interventions. Despite literature documenting the effectiveness of IPMPs, patients find it difficult to obtain authorization for these programs from third party insurance payers. The purpose of this quantitative causal comparative study was to explore whether a patient's perceived quality of life after injury but prior to treatment will affect his or her success in an IPMP. This study was based in the theoretical foundations of the biopsychosocial model of pain as well as positive psychology. Regression analysis and a test of mean differences were used to analyze the data to determine if there was a statistically significant difference in the perceived success in an IPMP program between patients who were part of a workers' compensation program (n = 77) and those who were not (n = 60). None of the null hypotheses could be rejected. Quality of Life Index (QOLI) scores were not predictive of success in an IPMP. None of the QOLI 16 subscales were predictive of success in an IPMP. Additionally, there was no significant difference between patients who were on workers' compensation and those who were not. This study contributes to the knowledge gap regarding appropriate screening tools for admittance into an IPMP. The results of this study can be used by practitioners who are trying to get patients approved for an IPMP and by third party insurance payer when determining which patients would most benefit from attending an IPMP.