The problems associated with the contamination of groundwater environments by non-aqueous phase liquids (NAPLs) such as chlorinated solvents, gasoline and manufacturing gas plant (MGP) residuals, including their distribution and persistence, are well accepted. The treatment of groundwater by in situ chemical oxidation (ISCO) relies on the oxidation potential of chemical reagents to destroy harmful organic compounds. The interaction of these oxidants with target and non-target compounds in the subsurface will help determine effectiveness and efficiency of an ISCO treatment system. Push-pull tests (PPTs) have the utility to estimate key properties in situ and allow for sampling a larger volume of aquifer to yield more representative estimates as compared to conventional bench-scale tests. The scale and cost-effectiveness of a PPT make it an ideal tool to collect valuable information on subsurface system behaviour so that uncertainties can be minimized. The use of PPTs to provide insight into treatment expectations or to support the design of an ISCO system requires a suitable interpretation tool. A multi-species numerical model (‘PPT-ISCO’) in a radial coordinate system was developed to simulate a PPT with the injection of a conservative tracer and oxidant (persulfate or permanganate) into the saturated zone of a porous medium environment. The pore space may contain variable amounts of immobile, multicomponent, residual NAPL. The aquifer material contains a natural organic matter (NOM) fraction and/or other oxidizable aquifer material (OAM) species. The model is capable of simulating mass transport for an arbitrary number of conservative and reactive tracers and NAPL constituents subjected to chemical reactions. The ability of PPTs to capture the in situ natural oxidant interaction (NOI) was tested with PPTISCO. Breakthrough curve (BTC) data collected from permanganate and persulfate PPTs conducted in the field were compared to simulated BTCs by assigning the same field operational parameters to the model and applying NOI kinetic information obtained from batch tests. These tests confirmed the usability of the model and PPTs to obtain the NOI kinetics from PPT BTCs. The sensitivity of PPT BTCs to variations in the field operating and NOI parameters were investigated. The results of varying the field operating parameters indicated that the oxidant BTCs could be scaled to match varying injection and extraction flow rates. Variations in NOI parameters revealed that the permanganate BTC is primarily controlled by the permanganate fast reaction rate coefficient and the quantity of OAM present in the aquifer. The spatial profiles of OAM across the test zone revealed that the majority of the OAM consumption is from the fast fraction and occurs in the vicinity of the well where the permanganate concentration is greatest. An estimate of the permanganate fast reaction rate coefficient can be obtained from a permanganate PPT BTC by employing the model to simulate the PPT with the operational parameters (used in the field) and literature estimates of the remaining NOI parameters. Calibration between the simulated and observed BTCs can be undertaken to adjust the permanganate fast reaction rate coefficient to fit the permanganate PPT BTC. Persulfate NOI sensitivity investigations revealed that persulfate PPT BTCs can be characterized by a concentration plateau at early times as a result of the increased ionic strength in the area around the injection well. The ionic strength is primarily controlled by the injected persulfate concentration, and as persulfate degrades into sulphate and acid, the ionic strength is enhanced. Graphical analysis of the BTC revealed that an underestimated value of the persulfate degradation rate coefficient can be obtained from the PPT BTC. A more representative estimate of the persulfate degradation rate coefficient can be achieved after fitting the field BTC to the simulated results, applying the underestimated value as a starting point. PPTs investigating ISCO treatability have the ability to provide insight into the effect of the NOI on the oxidation of target compounds, site-specific oxidant dosage requirements and NAPL treatment expectations. NAPL component BTCs from treatability PPTs are primarily controlled by the mass in the fast region, and the fast region mass transfer rate coefficient. Oxidation estimates extracted from NAPL component BTCs were shown to accurately approximate the mass of each NAPL component oxidized when compared to model calculations. The mass of NAPL oxidized for each of the components yields a site-specific oxidant dosage. This estimate exceeds what is prescribed by the stoichiometry between permanganate and the contaminant of concern due to the effect of the NOI. The utility of PPTs to study and quantify the interaction between injected oxidants and the aquifer material has been demonstrated with PPT-ISCO. In addition, PPT-ISCO has revealed that treatability PPTs can be tailored to investigate the dosage requirements and treatment expectations of residual NAPLs. Results from this effort will be used to support ongoing field research exploring the use of PPTs to assist in understanding the competing subsurface processes affecting ISCO applications.

The problems associated with the contamination of groundwater environments by non-aqueous phase liquids (NAPLs) such as chlorinated solvents, gasoline and manufacturing gas plant (MGP) residuals, including their distribution and persistence, are well accepted. The treatment of groundwater by in situ chemical oxidation (ISCO) relies on the oxidation potential of chemical reagents to destroy harmful organic compounds. The interaction of these oxidants with target and non-target compounds in the subsurface will help determine effectiveness and efficiency of an ISCO treatment system. Push-pull tests (PPTs) have the utility to estimate key properties in situ and allow for sampling a larger volume of aquifer to yield more representative estimates as compared to conventional bench-scale tests. The scale and cost-effectiveness of a PPT make it an ideal tool to collect valuable information on subsurface system behaviour so that uncertainties can be minimized. The use of PPTs to provide insight into treatment expectations or to support the design of an ISCO system requires a suitable interpretation tool. A multi-species numerical model (‘PPT-ISCO’) in a radial coordinate system was developed to simulate a PPT with the injection of a conservative tracer and oxidant (persulfate or permanganate) into the saturated zone of a porous medium environment. The pore space may contain variable amounts of immobile, multicomponent, residual NAPL. The aquifer material contains a natural organic matter (NOM) fraction and/or other oxidizable aquifer material (OAM) species. The model is capable of simulating mass transport for an arbitrary number of conservative and reactive tracers and NAPL constituents subjected to chemical reactions. The ability of PPTs to capture the in situ natural oxidant interaction (NOI) was tested with PPTISCO. Breakthrough curve (BTC) data collected from permanganate and persulfate PPTs conducted in the field were compared to simulated BTCs by assigning the same field operational parameters to the model and applying NOI kinetic information obtained from batch tests. These tests confirmed the usability of the model and PPTs to obtain the NOI kinetics from PPT BTCs. The sensitivity of PPT BTCs to variations in the field operating and NOI parameters were investigated. The results of varying the field operating parameters indicated that the oxidant BTCs could be scaled to match varying injection and extraction flow rates. Variations in NOI parameters revealed that the permanganate BTC is primarily controlled by the permanganate fast reaction rate coefficient and the quantity of OAM present in the aquifer. The spatial profiles of OAM across the test zone revealed that the majority of the OAM consumption is from the fast fraction and occurs in the vicinity of the well where the permanganate concentration is greatest. An estimate of the permanganate fast reaction rate coefficient can be obtained from a permanganate PPT BTC by employing the model to simulate the PPT with the operational parameters (used in the field) and literature estimates of the remaining NOI parameters. Calibration between the simulated and observed BTCs can be undertaken to adjust the permanganate fast reaction rate coefficient to fit the permanganate PPT BTC. Persulfate NOI sensitivity investigations revealed that persulfate PPT BTCs can be characterized by a concentration plateau at early times as a result of the increased ionic strength in the area around the injection well. The ionic strength is primarily controlled by the injected persulfate concentration, and as persulfate degrades into sulphate and acid, the ionic strength is enhanced. Graphical analysis of the BTC revealed that an underestimated value of the persulfate degradation rate coefficient can be obtained from the PPT BTC. A more representative estimate of the persulfate degradation rate coefficient can be achieved after fitting the field BTC to the simulated results, applying the underestimated value as a starting point. PPTs investigating ISCO treatability have the ability to provide insight into the effect of the NOI on the oxidation of target compounds, site-specific oxidant dosage requirements and NAPL treatment expectations. NAPL component BTCs from treatability PPTs are primarily controlled by the mass in the fast region, and the fast region mass transfer rate coefficient. Oxidation estimates extracted from NAPL component BTCs were shown to accurately approximate the mass of each NAPL component oxidized when compared to model calculations. The mass of NAPL oxidized for each of the components yields a site-specific oxidant dosage. This estimate exceeds what is prescribed by the stoichiometry between permanganate and the contaminant of concern due to the effect of the NOI. The utility of PPTs to study and quantify the interaction between injected oxidants and the aquifer material has been demonstrated with PPT-ISCO. In addition, PPT-ISCO has revealed that treatability PPTs can be tailored to investigate the dosage requirements and treatment expectations of residual NAPLs. Results from this effort will be used to support ongoing field research exploring the use of PPTs to assist in understanding the competing subsurface processes affecting ISCO applications.

Composite beams are frequently used in building, combining a steel beam with either a concrete-filled steel deck or solid concrete slab. To ensure proper composite action, shear connectors, typically in the form of headed shear studs, are utilized. Traditionally, the strength assessment of these headed shear studs is made using empirical design specifications that are based on push-out tests, which have been widely conducted and standardized over the years. However, the standardized push-out tests have short-comings, such as uneven slab bearing, slab buckling, questions regarding the distribution of load to each stud, etc. A study was conducted to evaluate and compare the existing push-out test setup with two alternative test setups. The study also aimed to examine the behavior of headed shear studs in composite beams having deck deeper the current allowable limit of 3 in., as specified by American Institute of Steel Construction (AISC) design specification. While the standard specification allows for steel decks with rib heights of up to 3 in., there are deck profiles deeper than 3 in. available in the market. Utilizing these deeper decks in composite beams offers several advantages, including faster and more cost-effective construction by reducing the number of beams required. This research therefore found that a major challenge in creating an alternative test setup involves eliminating moment at the interface between the concrete-filled steel deck and the steel beam. This moment leads to tension in the headed shear stud/stud group closest to the actuator, thus affecting the shear strength of the headed shear studs. Further, these headed shear studs have significant strength when used with 3.5 in. decks but further research is necessary. / Master of Science / Composite beams are widely used in building construction, combining a steel beam with either a concrete-filled steel deck or a solid concrete slab. To ensure their proper function, shear connectors are used, typically in the form of headed shear studs. Traditionally, the strength of these shear studs is determined using standardized push-out tests, but these tests some challenges like uneven slab bearing, questions about even load distribution, etc. In this study, the existing push-out test setup was evaluated and compared with two alternative setups. The behavior of headed shear studs in composite beams with deeper decks than the current allowable limit specified by design standards was also investigated. Using these deeper decks offers advantages such as faster and more cost-effective construction. One major challenge in creating an alternative test setup was eliminating the moment at the interface between the concrete-filled steel deck and the steel beam. This moment caused tension in the headed shear stud closest to the actuator, impacting the overall shear strength of the studs. Additionally, it was found that these shear studs show promising strength when used with 3.5 in. decks, but more research is needed to fully understand their capabilities. By exploring new test setups and considering deeper decks, this research contributes to improving the design and construction of composite beams, making them more efficient and reliable for future building projects.

Magister Chirurgiae Dentium - MChD / The aim of the study was to determine which of the three resin cements would produce the highest debond stress values with a double-tapered fibre post system. In the past, conventional parallel- sided prefabricated or cast metal posts have been used, which has considerable mechanical strength but lacks aesthetic capabilities. Post preparation techniques usually compromise the fracture strength of the treated anterior tooth. Double- tapered post systems ensure that anterior mutilated teeth can be restored and retained without compromising aesthetics or excessively weakening the remaining dental tissues. There are in-vitro results that support the strength of the double- tapered design, as well as the aesthetics of the material but there is little evidence regarding the retentive capabilities of the posts and which cement will ensure the best results (Grandini et al., 2008; Nakamura et al., 2005). Literature suggests that the two main causes for failure of a post system are root fracture and debonding of the post in the root canal (Toman et al., 2009; Radovic et al., 2008). The type of cement and cementation technique will have a significant influence on the treatment success of post and core restorations. This study compared the debond stresses required to remove a double- tapered post system from a prepared post space with 3 different cements to assess which cement will be most resistant to the post debonding.

This article reviews the design and behaviour of composite beams with precast hollow core slabs in multi-storey buildings for gravity loading. A brief history of composite construction and introduction to precast¿composite construction is given, followed by an overview of recent research work on various factors affecting the design. This includes the push-off test procedure, the load¿slip characteristic of the headed shear studs and the design procedures for this type of construction. Finite element modelling of the headed stud shear connectors and the composite beams with precast hollow core slabs are presented. Finally, recommendations and future research work is also suggested.

The behavior and strength of welded shear studs are subjects of ongoing study. In recent years, research has shown that the American Institute of Steel Construction (AISC) specification equations for shear stud strength are unconservative for studs placed in deck with ribs transverse to the steel beam. Twenty-four solid slab push-out tests, 93 composite slab push-out tests, and bare stud tests were performed to study the effects on stud strength of friction, normal load, position of studs in the ribs of steel deck, concrete strength, and stud properties. Stud diameters ranged from 3/8 in. to 7/8 in., deck heights ranged from 2 in. to 6 in., and both single and pairs of studs were tested. The push-out test results from this study were combined with other studies to propose a new stud strength prediction model. Three new beam tests were performed to study the effect of the stud position in the ribs of the steel deck. The results of these tests, along with 61 other beam tests, were used to verify the new stud strength prediction model. A reliability study was performed to determine resistance factors for stud strength and beam strength. / Ph. D.

Cast-in-place concrete in composite with steel sections is commonly used in bridge deck constructions. The shear transfer between the concrete and steel section is achieved by shear connectors and the strength calculation of conventional shear connectors, i.e. shear studs, is provided in various design codes in North America. Due to the fact that the strength equation is largely based on experimental results, the applicability of the equation is only warranted where the design matches the experimental configuration of the test specimens. Thus, the codes specify detailing requirement for the stud height and the elevation of the reinforcement mesh in relation to the stud height. However, these requirements, in particular, the elevation of the reinforcement mesh, may be difficult to meet accurately in construction practice. The implications of not meeting the mesh requirement to the strength of the shear stud and the remedy solutions are examined in this study. An experimental program involving the test of thirty-three push-out specimens was designed and conducted with a focus on the shear studs' performance. Testing parameters included reinforcement mesh position, shear stud height, presence of stud head, shear stud spacing, and steel flange surface treatment. In addition, the performance of a new type of shear studs, referred to as adjustable studs, was also studied experimentally. The ultimate load and load vs. slip curves were presented and discussed in the forms of tables and graphs. The failure modes were noted and the relationship between the failure modes and the ultimate capacity was discussed. Ultimate loads obtained from specimens were then used to assess the efficacy of code suggested values. Results showed that depending on the elevation of reinforcement mesh, three failure modes were observed including concrete related failure, combined concrete failure and bent studs and stud shear-off from the steel flange. The elevation of the reinforcement mesh had a significant effect on the ultimate load of the specimen. As the mesh elevation increased from intercepting the stud to being in flush with the top of the stud to above the stud, the ultimate load decreased. Specimens with unheaded shear studs had lower ultimate load than specimens with headed shear studs. Flange treatment had an impact on the ultimate load, where the coating on flanges resulted in a decrease in the ultimate load. Test results also showed that the close placement of the shear studs result in a reduction on the ultimate load when the other parameters were kept the same. In the comparison between conventional and adjustable shear studs, specimens with adjustable studs shared similar failure mode to those with conventional studs, but attained on average lower load capacity. The comparison with the code suggested values showed that the code suggested value is only ensured when double-layer reinforcement mesh is used and placed at code specified elevation. A single layer mesh intercepting the studs resulted in the ultimate load slightly lower than the code value. The code values for adjustable studs are markedly higher than the experimental value, which raises the question whether the code equation for conventional studs is directly transferrable to adjustable studs.

Made available in DSpace on 2015-05-08T14:59:42Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 4158784 bytes, checksum: 614ac248aca292bc7e1a840fb03f4a7f (MD5) Previous issue date: 2012-08-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Oil has become one of the greater sources of energy in the contemporary world and ensures that its extraction is done without loss of production wells and structurally reliable is essential. Cementitious coatings of oil wells are used in order to ensure structural support of the wells and corrosion protection. In these structures, the adhesion between steel and cementitious material is responsible for ensuring the mechanical and the thermodynamical efficiencies, protecting them against corrosion, preventing the escape of fluids inside and isolating the hydraulic structure against infiltrations. The push-out test is used to measure the adherence between steel and cement. In this work, the numerical simulation of steel-cement interface was carried. For reproducing the mechanical behavior of this interface, a cohesive-zone model, formulated from the perspective of Damage Mechanics, combined with Coulomb's law for friction were used. The proposed model was implemented in CAST3M software. The numerical results obtained with the proposed model were compared with experimental results of push-out tests made with three different interface conditions. The comparison between the force versus displacement curves obtained experimentally and numerically validated the proposed model. / O petróleo tornou-se uma das principais fontes de energia do mundo contemporâneo e garantir que sua extração seja feita sem que haja perdas de produção e com poços estruturalmente confiáveis é fundamental. Os revestimentos cimentícios dos poços de petróleo são utilizados no intuito de garantir suporte estrutural aos poços e proteção contra corrosão. Nessas estruturas, a adesão entre o aço e o material cimentício é responsável por garantir a eficiência tanto do ponto de vista mecânico, garantindo suporte estrutural, quanto da estabilidade termodinâmica dos aços, protegendo-os contra a corrosão, impedindo a fuga de fluidos de seu interior e isolando hidraulicamente a estrutura contra infiltrações. O ensaio de arrancamento, também conhecido como push-out test, é utilizado no intuito de mensurar o nível de aderência entre o aço e o cimento. Neste trabalho, a simulação numérica da interface aço-cimento foi realizada. Para a reprodução do comportamento mecânico desta interface, utilizou-se um modelo de zona coesiva formulado sob a ótica da Mecânica do Dano combinado com a lei de Coulomb para o atrito. O modelo proposto foi implementado no software CAST3M. Os resultados numéricos obtidos com o modelo proposto foram comparados com resultados experimentais de ensaios de arrancamento feitos com três diferentes condições de interface: Tubo de aço limpo e seco (LS), tubo de aço borrifado com solução de NaCl em água (NaCl) e tubo de aço revestido por um cimento geopolimérico (GEO). A comparação entre as curvas força versus deslocamento, obtidas experimentalmente e numericamente, validaram o modelo proposto.

O objetivo deste estudo foi avaliar a resistência de união à dentina da obturação de canais radiculares com cimentos à base de resina epóxica e de metacrilato, por meio do dispositivo material testing stage (MTS) acoplado ao microtomógrafo (&mu;CT), bem como avaliar qualitativamente a ruptura da massa obturadora por meio de imagens de &mu;CT. Além disso, foram utilizados o método de elementos finitos 3D e microscopia confocal de varredura a laser (MCVL) para verificar, respectivamente, a distribuição de tensões e presença de gaps na interface de união. Raízes de caninos superiores com 17 mm de comprimento foram submetidas ao preparo biomecânico com instrumentos rotatórios de níquel titânio, sob irrigação constante com NaOCl 1% e irrigação final com EDTA 17%. Os canais foram obturados pela técnica da condensação lateral com cones de guta percha e os cimentos: AH Plus, Epiphany SE ou RealSeal XT. As raízes foram armazenadas (100% de umidade, 37°C) por três vezes o tempo de endurecimento do cimento utilizado. Após este período, as raízes foram seccionadas para obtenção de dois slices (2 mm) de cada terço radicular. Um slices de cada terço foi submetido ao teste de push-out através de dispositivo mecânico MTS acoplado ao &mu;CT SkyScan 1174 (50kV, 80mA). Após o escaneamento inicial do slices, com resolução isotrópica de 13 &mu;m, filtro de 0.5 mm de Al e 360º de rotação, o teste mecânico foi iniciado até que ocorresse o deslocamento do material. Novo escaneamento foi realizado com os mesmos parâmetros iniciais, que determinou regiões de ruptura da massa obturadora em secções axiais. Os tipos de falhas foram avaliados por MCVL e classificadas em: adesivas, coesivas e mistas. Modelos 3D de elementos finitos foram gerados para os terços cervical, médio e apical, a partir de imagens de &mu;CT. No segundo slices de cada terço radicular, foi aferido o percentual de gaps do material obturador às paredes do canal radicular, por meio de MCVL e do programa OLS 4000. Os dados foram analisados por testes estatísticos paramétricos e não paramétricos (p<0,05). O cimento AH Plus [1,89 (1,01/2,39) MPa] apresentou maior resistência de união à dentina (p<0,001) quando comparado aos cimentos Epiphany SE [0,36 (0,29/0,44) MPa] e RealSeal XT [0,43 (0,32/0,54) MPa]. Para os cimentos AH Plus e RealSeal XT, os terços cervical e médio apresentaram maior resistência de união à dentina que o terço apical (p<0,001). As rupturas ocorreram nas margens da massa obturadora para o cimento AH Plus, enquanto os cimentos Epiphany SE e RealSeal XT tiveram este tipo de ruptura, bem como na própria massa obturadora. No cimento AH Plus, a interface de união mostrou maior concentração de tensões, que foram distribuídas principalmente na massa obturadora para os cimentos Epiphany SE e RealSeal XT. Houve predominância de falhas adesivas e mistas em todos os cimentos. Em relação ao percentual de gaps, o cimento AH Plus apresentou as menores médias (11,14% ± 4,03), com diferença estatisticamente significante (p<0,05) dos cimentos Epiphany SE (55,39% ± 13,46) e RealSeal XT (62,50% ± 6,72). O cimento à base de resina epóxica (AH Plus) apresentou a maior resistência de união à dentina e teve comportamento diferente em relação aos outros cimentos, quanto à ruptura da massa obturadora e distribuição de tensão interfacial. Além disso, o cimento AH Plus apresentou o menor percentual de gaps entre o material obturador e as paredes do canal radicular / The aim of this study was to evaluate the bond strength of epoxy resin- and methacrylate-based sealers to root dentin, using the material testing stage (MTS) coupled to a micro-computed tomography (&mu;CT) device and to qualitatively assess the root-filling mass rupture by &mu;CT images. Additional analyses were conducted using the 3D element finite method and confocal laser scanning microscopy (CLSM) to verify, respectively, the stress distribution and percentage of gaps on dentin filling material interfaces. Maxillary canine roots measuring 17 mm were subjected to biomechanical preparation with nickel-titanium rotary instruments under constant irrigation with 1% NaOCl and final irrigation with 17% EDTA. Canals were filled by the lateral condensation technique with gutta-percha cones and the following sealers: AH Plus, Epiphany SE or RealSeal XT. The roots were stored (100% humidity, 37 °C) for a period three times longer than the setting time required for each sealer and then sectioned transversally to obtain two 2-mm-thick slices from each root third. One slice of each third was subjected to the push-out test using the MTS coupled to the SkyScan 1174 &mu;CT (50 kV, 80 mA) with 13 &mu;m isotropic resolution, 0.5 mm Al filter and 360° rotation. After the initial scanning of the slice, the mechanical test was performed until material dislodgement occurred. A new scanning was performed using the same initial parameters. The axial sections obtained were used for qualitative evaluation of the root-filling mass rupture. Failure modes were assessed by CLSM and classified as adhesive, cohesive or mixed. 3D &mu;CT based finite element models were generated from cervical, middle and apical root thirds to simulate the push-out test. The second slice of each root third was used to assess the percentage of gaps between the filling material and the root canal walls, using CLSM with the aid of the OLS 4000 software. The data were analyzed by parametric and non-parametric tests (p<0.05). AH Plus presented higher bond strength [1.89 (1.01/2.39) MPa] to dentin (p<0.001) than Epiphany SE [0.36 (0.29/0.44) MPa] and RealSeal XT [0.43 (0.32/0.54) MPa]. For AH Plus and RealSeal XT sealers, the cervical and middle thirds showed higher bond strength to dentin than the apical third (p <0.001). The ruptures occurred in the margins of the root filling mass for AH Plus, while Epiphany SE and RealSeal XT had this type of rupture as well as in the root filling mass itself. AH Plus showed stress concentration on bond interface, while in Epiphany SE and RealSeal XT the stress was mainly distributed on the root-filling mass. Adhesive and mixed failures were the predominant fracture modes in all sealers. Regarding the percentage of gaps between the filling material and the root canal walls, AH Plus presented the lowest means (11.14%±4.03), differing significantly (p<0.05) from Epiphany SE (55.39%±13.46) and RealSeal XT (62.50%±6.72) sealers. The epoxy resin-based sealer (AH Plus) presented the highest bond strength to dentin, which had different behavior from other sealers regarding root-filling mass rupture and interfacial stress distribution. Moreover, AH Plus resulted in the lowest percentage of gaps between the material and the root canal walls

Este estudo avaliou a resistência ao deslocamento vertical push-out de pinos de fibra de vidro cimentados à dentina intra-radicular utilizando uma resina fluida padrão como agente cimentante em combinação com um adesivo dentinário experimental e um adesivo disponível comercialmente. 20 pré-molares unirradiculares humanos foram previamente extraídos e tratados endodonticamente. Os espécimes foram divididos em quatro estratégias de união a dentina: Grupo 1 com adesivo experimental com etanol na proporção em volume 1:1 (resina/etanol) e Grupo 2 com adesivo experimental com etanol na proporção em volume 1:2(resina/etanol); adesivos experimentais aplicados de acordo com a técnica úmida de adesão simplificada com etanol, Grupo 3: One-Step Plus aplicado de acordo com a técnica úmida de adesão simplificada com etanol; Grupo 4: One-Step Plus aplicado seguindo as instruções do fabricante. Os espécimes foram seccionados em fatias de 1 mm de espessura e apos o teste push-out foi realizado. Espécimes representativos foram selecionados para exame ultra-estrutural. Não houve diferença estatística na resistência ao deslocamento push-out entre as estratégias testadas de adesão (p> 0,05). O padrão predominante de fratura foi entre os pinos de fibra e o agente cimentante. A partir deste estudo devemos considerar como promissora a técnica com etanol utilizada na cimentação de pinos no canal radicular devido aos possíveis benefícios das resinas altamente hidrófobas. Mais estudos são necessários para validar o uso da técnica úmida de adesão simplificada com etanol quando cimentados pinos de fibra. / This study evaluated the push-out bond strength of glass fiber posts adhesively bonded to intraradicular dentin using a standard unfilled resin as luting agent in combination with an experimental and a commercially available adhesive. Twenty extracted single-rooted human teeth were endodontically treated. Specimens were assigned to 4 dentin bonding strategies: Group 1 (co-monomers to ethanol on ratio 1:1) and Group 2 (co-monomers to ethanol on ratio 1:2): Experimental adhesives applied in accordance with the simplified ethanol-wet bonding technique; Group 3: One-Step Plus (OSP) applied in accordance with the simplified ethanol-wet bonding technique; Group 4: OSP applied following manufacturers instructions. Bonded specimens were sectioned in 1-mm-thick slices and the push-out test was performed. Representative specimens were selected for ultrastructural examination. No statistical differences in push-out bond strength were found among the tested bonding strategies (p>0.05). The major failure pattern was between the post and the luting cement. From this study the ethanol technique should be considered as a promising approach in the luting of fiber posts into the root canal due to the possible benefits of highly hydrophobic resins. Further studies are needed to validate the use of the ethanol-wet bonding technique when luting a fiber post.