Download or read book Experimental Evaluation of the Behavior of Spirally reinforced High strength Concrete Columns written by Annette M. Pieroni and published by . This book was released on 1995 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Evaluation of the Axial Load Behavior of Tied High strength Concrete Columns written by Wen-Hsiung Lin and published by . This book was released on 1996 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Behavior of Spirally Reinforced High Strength Concrete Columns Under Axial Loading written by David L. Montgomery and published by . This book was released on 1996 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation was conducted to study the behavior of spirally reinforced high strength concrete (HSC) columns subjected to axial compression loading. The main objective of the experiment was to investigate the effects of the volumetric ratio of spiral steel, the spiral spacing, the specimen size and the concrete strength on the strength and ductility performance of confined concrete. Behavior of the cover concrete, spiral reinforcement steel, and longitudinal reinforcing bars were also investigated to gain insight into the overall behavior of HSC columns. A total of 32 spirally reinforced HSC columns were tested, including ten 254 mm diameter columns with concrete strength f'c of 69.7 Mpa, nine 203 mm diameter columns with concrete strength f'c of 69.7 MPa, and thirteen 203 mm diameter columns with concrete strength f 'c of 89.8 MPa. Overall height of each specimen was four times the diameter. All of the specimens were reinforced longitudinally with five deformed reinforcement bars and laterally by various amounts of spiral reinforcement. An increase in the volumetric ratio of spiral steel resulted in increases in the strength and ductility of confined HSC, with the improvements in ductility being more pronounced. Reductions in spiral spacing resulted in improved strength and ductility of confined HSC when the volumetric ratio of spiral steel was sufficiently large. Increases in concrete strength were found to result in decreases in the peak strength enhancement, axial strain at peak strength, spiral stress at peak strength, and deformability of the specimens. Larger diameter columns achieved better participation of the cover concrete shell and had larger strengths at low axial strains. Cover concrete began spalling at lower concrete strengths and at earlier axial strains than expected in the columns with f'c of 89.8 MPa.

Download or read book Behavior of Spirally Reinforced High Strength Concrete Columns Under Axial Loading written by and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spirally reinforced High strength Concrete Columns written by Salvador Martinez Morales and published by . This book was released on 1983 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Evaluation of High strength Concrete Circular Columns Reinforced with GFRP Bars and Spirals written by Mu'taz Almomani and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of fifteen large-scale high-strength concrete (HSC) columns internally reinforced with GFRP bars and spirals are presented in this thesis. The concrete dimensions and reinforcement of the columns satisfied all the minimum requirements of the relevant Canadian standards. The test parameters in this study include reinforcement type (steel or GFRP), spiral pitch (50 or 85 mm), slenderness ratio (14, 20 or 28), the level of axial load eccentricity (60, 90, 120 or 150 mm) and the loading type (axial or flexural loading). The experimental results were then compared to the predictions of the Canadian and American FRP design codes and guidelines. Compared to the GFRP-reinforced concrete (RC) counterpart, the steel-RC specimen achieved a higher axial capacity (7.8%) with very similar behaviour up to the peak load but a more ductile post-peak behaviour. Both spiral pitches were able to provide adequate confinement up to the peak load, however, the smaller pitch was able to provide a more deformable post-peak behaviour. As the slenderness ratio increased, the lateral displacement increased and the lateral and axial stiffness decreased. The effect of increasing axial load eccentricity was more pronounced than the increase in slenderness ratio and resulted in reduced axial and lateral stiffness. The GFRP reinforcement was able to contribute to the carrying load capacity of both the axially-loaded columns and those under flexure. No failure of any bars or spirals was observed with the exception of the shortest column under the least eccentricity. Under flexural loading, the spirals were able to provide adequate confinement at different loading stages until failure. When compared with the experimental results, the examined codes and guidelines were found to be conservative in predicting the capacities of the columns for all loading conditions and slenderness ratios.

Download or read book Proceedings of CIBv 2023 written by Ioan Tuns and published by Springer Nature. This book was released on with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the 9th International Conference on Civil Engineering written by Guangliang Feng and published by Springer Nature. This book was released on 2023-06-17 with total page 627 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book is a compilation of selected papers from the 9th International Conference on Civil Engineering (ICCE2022). The work focuses on novel research findings on seismic technology of civil engineering structures, High-tech construction materials, digitalization of civil engineering, urban underground space development. The contents make valuable contributions to academic researchers and engineers.

Download or read book 10th International Conference on FRP Composites in Civil Engineering written by Alper Ilki and published by Springer Nature. This book was released on 2021-11-26 with total page 2516 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume highlights the latest advances, innovations, and applications in the field of FRP composites and structures, as presented by leading international researchers and engineers at the 10th International Conference on Fibre-Reinforced Polymer (FRP) Composites in Civil Engineering (CICE), held in Istanbul, Turkey on December 8-10, 2021. It covers a diverse range of topics such as All FRP structures; Bond and interfacial stresses; Concrete-filled FRP tubular members; Concrete structures reinforced or pre-stressed with FRP; Confinement; Design issues/guidelines; Durability and long-term performance; Fire, impact and blast loading; FRP as internal reinforcement; Hybrid structures of FRP and other materials; Materials and products; Seismic retrofit of structures; Strengthening of concrete, steel, masonry and timber structures; and Testing. The contributions, which were selected by means of a rigorous international peer-review process, present a wealth of exciting ideas that will open novel research directions and foster multidisciplinary collaboration among different specialists.

Download or read book Confinement of Normal and High strength Concrete Columns written by Salim R. Razvi and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive research project was conducted to investigate the behaviour and design of earthquake resistant normal-strength and high-strength concrete columns. The project included three essential components; testing of full size columns, development of an analytical model, and development of a design procedure. The experimental program consisted of material research and structural testing. The first phase was designed to study mechanical properties of high-strength concrete, which involved testing of a large number of concrete cylinders. The second phase was designed to investigate performance of confined normal and high-strength concrete columns under concentric compression. The experimental program included tests of 46 full size square and circular columns, with concrete strength ranging between 60 MPa and 124 MPa. The parameters considered included; cross-sectional shape (circular and square), volumetric ratio and spacing of transverse reinforcement, distribution of longitudinal reinforcement and resulting tie arrangement, yield strength of transverse reinforcement, concrete compressive strength, influence of longitudinal reinforcement in circular columns, and type of circular reinforcement (continuous spiral and circular hoops). The analytical component of the research program involved development of a mathematical model to represent stress-strain relationship of confined concrete. This was done in two steps. The first step included formulation of the relationship for normal strength concrete, for which extensive test data was available. The second step involved modification of the model for high-strength concrete. An extensive literature survey was first conducted, followed by evaluation of previous test data. This information was used, along with the results of the experimental phase of this investigation to develop a generalized cofinement model for normal-strength and high-strength concrete columns. The analytical and experimental research was used in developing a design procedure for confinement of earthquake resistant concrete columns. The procedure includes all the relevant parameters of confinement that have been observed to be important in column tests, and relates the design variables to deformation capacities. A displacement based design methodology was developed, where the lateral drift demand is a design parameter. This approach leads to different confinement steel requirements for columns with different deformability demands, an approach currently lacking in practice. Furthermore, the reinforcement arrangement is recognized as a design parameter, allowing lower volumetric ratio of confinement reinforcement for efficient arrangements. This may result in significant savings in steel, eliminating the common problem of steel congestion in earthquake resistant columns. (Abstract shortened by UMI.).

Download or read book Normal strength and High strength Concrete Columns Under Cyclic Axial Load and Biaxial Moment written by Mehdi Zarei and published by . This book was released on 2016 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: The technique of using Carbon Fiber Reinforced Polymer (CFRP) materials to repair and strengthen various concrete members has become popular in the structural retrofitting field as an effective way to enhance the strength and ductility of concrete members due to its superior mechanical properties. In this study a method was introduced to study the behavior of concrete columns with and without CFRP jackets under constant axial load and variable lateral load. The lateral load was applied monotonically and cyclically. To predict the behavior of concrete columns under monotonic and cyclic compressive loadings, a computer code was developed to produce the moment-curvature diagram for concrete sections. The moment-curvature diagram was then input in SAP2000 to study the behavior of reinforced concrete columns. The result of this analysis was found to correlate with experimental data well. The behavior of high-strength concrete (HSC) columns having various properties and subjected to a variety of loading conditions has been the topic of considerable investigation. Of particular significance in this area is the behavior of HSC columns under cyclic compressive load with bidirectional eccentricity. For the experimental investigation, tests of six square slender HSC columns were conducted under stroke control to achieve both ascending and descending branches of the load-deformation curves. Analysis of HSC columns subjected to cyclic axial compression with bidirectional eccentricity was approached from the standpoint of a three-dimensional problem. A computer program based on the extended finite segment method and accounting for geometrical nonlinearity has been proposed here to predict the load-deflection curves of HSC columns under cyclical loading. The HSC stress-strain relationship obtained by parametric study and experimental investigation into the behavior of concrete under cyclical load history has been incorporated into the numerical procedure. The presented computer analysis results have been compared with the experimental data, and a satisfactory agreement was attained for both the ascending and descending branches of the load-deformation curves.

Download or read book Behavior of High Strength Concrete Columns written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of high-strength concrete for bridges and high-rise buildings become popular due to development in concrete technology and availability of various types of mineral and chemical admixtures. High-strength concrete could lead to smaller member sizes for compression members and therefore provide considerable savings associated with material costs and reduction of dead loads. However, Most of the current design codes, such as AASHTO-LRFD Bridge Specifications, are still based on tests conducted using normal-strength concrete. Many studies indicate that the behavior of columns with high-strength concrete is different from that of normal-strength concrete. The experimental phase of this investigation consists of thirty two rectangular and twenty four circular columns subjected to concentric and eccentric loading conditions to investigate the behavior of high-strength concrete columns. The main variables considered in this study were concrete strength ranging from 7.9 to 16.5 ksi, shape of cross section, and longitudinal and transverse reinforcement ratios. Using the test results of this study and other researches in literature, the dissertation provides design equation to predict the capacity of high-strength concrete columns with tie and spiral reinforcements subjected to concentric and eccentric loading conditions up to 18 ksi. The research also proposes a new stress-strain relationship of high-strength concrete confined with spiral reinforcements.

Download or read book Behavior of Circular Concrete Columns Reinforced with FRP Bars and Stirrups written by Mohammad Afifi and published by . This book was released on 2013 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 [alpha][indice inférieur g] and [alpha][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.

Download or read book Experimental Studies on Flexural Behavior of Reinforced Concrete Columns Using High strength Concrete written by Yuuki Sakai and published by . This book was released on 1990 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Analysis and Experimental Investigation of Ultra high performance Concrete Hybrid Bridge Deck Connections written by Sabreena Nasrin and published by . This book was released on 2019 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, the use of modular bridge deck components has gained popularity for facilitating more durable components in bridge decks, but these components require field-applied connections for constructing the entire bridge. Ultra-High-Performance Concrete (UHPC) is being extensively used for highway bridges in the field connections between girders and deck panels for its superior quality than conventional concrete.Thus far, very limited data is available on the modeling of hybrid-bridge deck connections. In this study, finite element models have been developed to identify the primary properties affecting the response of hybrid deck panel system under monotonic and reverse cyclic loads. The commercial software ABAQUS was used to validate the models and to generate the data presented herein. The concrete damage plasticity (CDP) model was used to simulate both the conventional concrete and UHPC. In addition, numerical results were validated against experimental data available in the literature. The key parameters studied were the mesh size, the dilation angle, reinforcement type, concrete constitutive models, steel properties, and the contact type between the UHPC and the conventional concrete. The models were found to capture the load-deformation response, failure modes, crack patterns and ductility indices satisfactorily. The damage in concrete under monotonic loading is found higher in normal concrete than UHPC with no signs of de-bonding between the two materials. It is observed that increasing the dilation angle leads to an increase in the initial stiffness of the model. Changing the dilation angle from 20℗ʻ to 40℗ʻ results in an increase of 7.81% in ultimate load for the panel with straight reinforcing bars, whereas for the panel with headed bars, the increase in ultimate load was found 8.56 %.Furthermore, four different types of bridge deck panels were simulated under reversed cyclic loading to observe overall behavior and the damage pattern associated with the reversed cyclic load. The key parameters investigated were the configurations of steel connections between the precast concrete deck elements, the loading position, ductility index, and the failure phenomena. The headed bar connections were found to experience higher ductility than the ones with straight bars in the range of 10.12% to 30.70% in all loading conditions, which is crucial for ensuring safe structural performance. This numerical investigation provides recommendations for predicting the location of the local damage in UHPC concrete bridge deck precast panel connections under reversed cyclic loading.Despite of having excellent mechanical and material properties, the use of Ultra-High-Performance Fiber Reinforced Concrete (UHP-FRC) is not widespread due to its high cost and lack of widely accepted design guidelines. This research also aims to develop a UHPC mixture using locally and domestically available materials without heat curing in hopes of reducing the production cost. Several trial mixtures of UHPC have been developed using locally available basalt and domestically available steel fibers. Among them, one trial mixture of 20.35 ksi compressive strength was selected for further study. To investigate the applicability of this locally produced UHPC in bridge closure, two full scale-8 ft. span hybrid bridge deck slabs with UHPC closure were constructed and tested under monotonic loading to identify the structural and material responses. The load-deflection response of the hybrid connection confirms that the deflection increased linearly until the initiation of first crack, after that it increased non-linearly up to the failure of the connection. The strain response also confirms that UHPC experiences less strain than normal strength concrete under compression loading. In addition, a moment curvature analytical graphical user interface model of hybrid bridge deck connection has been developed using MATLAB to predict ductility, curvature, and the stress distributions in those connections. The predicted value of moment and curvature from the code was found in good agreement with experimental data as well. The code provides a tool to professional engineers to predict ductility, curvature, and the stress distributions in those connections. The code is built in such a way to allow various input parameters such as concrete strength, dimensions of hybrid connection and deck panels, reinforcement configuration and the shape of the connection.Though, ultra-high-performance fiber reinforced concrete (UHP-FRC) has very high compressive strength compared to conventional concrete, the failure strain of UHP-FRC is not enough to withstand large plastic deformations under high stain rate loading such as impact and blast loading. Hence, a numerical study has been conducted to simulate low-velocity impact phenomenon of UHP-FRC. The responses obtained from the numerical study are in good agreement with the experimental results under impact loads. Five different types of UHP-FRC beams were simulated under impact loading to observe the global and local material responses. The key parameters investigated were the reinforcement ratio (Ï1), impact load under various drop heights (h), and the failure phenomena. It was observed that higher reinforcement ratio showed better deflection recovery under the proposed impact. Also, for a specific reinforcement ratio, the maximum deflection increases approximately 15% when drop height decreases from 100 mm to 25 mm. Moreover, the applicability of concrete damage plasticity model for impact loading is investigated. The results also provided recommendations for predicting the location of the local damage in UHP-FRC beams under impact loading.Moreover, this research work includes a nonlinear finite element analysis of high-strength concrete confined with opposing circular spiral reinforcements. The spiral reinforcement is a very common technique used for reinforcing columns in active seismic regions due to its high ductility and high energy absorption. The results are compared with previously tested small-scale concrete columns made with the same technique under monotonic axial loads. The proposed technique is developed to improve the strength and ductility of concrete columns confined with conventional spiral systems. The finite element (FE) analysis results have shown that the proposed model can predict the failure load and crack pattern of columns with reasonable accuracy. Beside this, the concrete plasticity damage showed very good results in simulating columns with opposing spirals. The FE model is used to conduct a study on the effect of spiral spacing, Îđ (ratio of the core diameter to the whole cross section diameter) and compressive strength on the behavior of circular spiral reinforced concrete columns confined with opposing circular spiral reinforcements. The results of the parametric study demonstrated that for the same spacing between spirals and same strength of concrete, increasing Îđ increases the failure load of the column. It is also observed from the study that the ductility of the studied columns is not affected by changing the value of Îđ. In addition, a correlation between the Îđ factor, three different compressive concrete strengths, and the spacing of opposing spirals was developed in this study.

Download or read book Advances in Civil Engineering Materials written by Elham Maghsoudi Nia and published by Springer Nature. This book was released on 2023-01-01 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents selected articles from the 6th International Conference on Architecture and Civil Engineering 2022 (ICACE 2022), held in Malaysia. Written by leading researchers and industry professionals, the papers highlight recent advances and addresses current issues in the fields of civil engineering and architecture.

Download or read book Design of Concrete Structures Using High strength Steel Reinforcement written by Bahram M. Shahrooz and published by Transportation Research Board. This book was released on 2011 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Report 679: Design of Concrete Structures Using High-Strength Steel Reinforcement evaluates the existing American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) Bridge Design Specifications relevant to the use of high-strength reinforcing steel and other grades of reinforcing steel having no discernible yield plateau. The report also includes recommended language to the AASHTO LRFD Bridge Design Specifications that will permit the use of high-strength reinforcing steel with specified yield strengths not greater than 100 ksi. The Appendixes to NCHRP Report 679 were published online.