Bearing Plates Research Articles

Effect of Web Perforations on the Web Buckling Resistance of 7075-T6 and AA-6086 High-Strength Aluminium Alloy C-Shaped Members under End-Two-Flange Loading Case

Recently, new types of C-shaped members made from AA-6086 and 7075-T6 high-strength aluminium alloy have become more popular due to their high yield strength and lower cost. These members are often manufactured with pre-punched web perforations to simplify the installation of services, but this can reduce their strength. Also, such aluminium C-shaped members that contain perforated webs are vulnerable to web buckling failure, as aluminium alloy has a lower elastic modulus compared to steel. However, this influence has not been investigated for high-strength aluminium alloy sections to date. An extensive numerical investigation was undertaken to examine the effect of web perforations on the web buckling resistance of high-strength aluminium alloy C-shaped members under an end-two-flange (ETF) loading case, and this study focused on two types of aluminium alloys, namely 7075-T6 and AA-6086. To achieve this, a nonlinear finite element (FE) model was developed and validated using the test data in the literature. The material properties used in the FE models were obtained from the relevant literature. A parametric investigation was carried out, consisting of a total of 1458 models. In this investigation, a number of variables were examined, including the web hole size, web hole location, bearing length, fillet radius and aluminium alloy grades. The results showed that increasing the a/h ratio from 0.1 to 0.5 resulted in a decrease of 9.7% and 9.3% in the web buckling resistance for the 7075-T6 aluminium and AA-6086 aluminium, respectively. When the length of the bearing plates (N) varied from 100 mm to 200 mm, the web buckling resistance experienced an average increase of 61.7% for the 7075-T6 aluminium and 54.1% for the AA-6086 aluminium. Also, the web buckling resistance increased by 6.2% for the 7075-T6 aluminium alloy, while the strength increased by 4.0% for the AA-6086 aluminium alloy when the x/h ratio increased from 0.1 to 0.5. The numerical data generated from the parametric study were used to assess the accuracy and suitability of the latest design recommendations, and it was found that the design rules presented in the previous literature cannot provide reliable and safe predictions for estimating the web buckling resistance of aluminium C-shaped members that contain perforated webs under an ETF loading case. Finally, new design formulas were proposed in the form of strength reduction factors. A reliability assessment was then undertaken, and the results of this analysis indicated that the proposed design formulas can accurately predict the web buckling resistance of such members with perforated webs.

Effect of the type of posttensioning anchorage on the behavior of anchorage zones

AbstractIn order to study the cracking behavior and the bearing strength of anchorage zones of posttensioning tendons using different types of anchorages, an experimental research has been performed using concrete prismatic specimens. The studied variables included the type of anchorage and the cross‐section dimensions, so the experimental program included eight prismatic specimens, four with 265 mm × 265 mm × 580 mm and four with 300 mm × 300 mm × 600 mm, reinforced with spirals and stirrups, and with two different types of anchorages. The concrete strains were measured to monitor cracking and to assess the relation between all the different variables involved on cracking and on the ultimate loads. The experimental cracking and ultimate loads were compared with models found in the literature. From the presented work, it can be concluded that the use of simple anchorage bearing plates leads to higher cracking and failure loads. This difference is more significant for cases with smaller cross‐sections.

Stress Analysis and Structural Optimization of Steel–Concrete Joint of Zhonghua Road Bridge in Liaocheng

Based on Zhonghua Road Bridge in Liaocheng city, a single tower hybrid cable-stayed bridge, the stress of the steelconcrete joint of the girder is studied using the finite element method with the software MIDAS and ANSYS. The beam element model of the whole bridge is established in MIDAS CIVIL, from which the internal forces of the critical sections of the steel–concrete joint under six adverse conditions are obtained. Then, the results are applied in the refined solid-shell finite element model established in ANSYS. With the stress analysis, it is found that when the steel–concrete joint is used in the girder of the single tower cable-stayed bridge, both the compressive strength of concrete and the tensile strength of steel can be fully used, and the structural stiffness can be smoothly transferred through the two different materials in the joint, which makes the structural behavior more reasonable. The detailed stress analysis also shows that it is prone to generate considerable stress concentration at the corners and the connection between the steel lattice chamber and the pressure bearing plate, and the concentration can be avoided by local stiffening and smoothing of the chamfers. The sensitivity analysis of the web thickness in the joints and bearing plates showed that increasing the thickness of the intermediate web would lead to a moderate reduction in the stress of the web itself, while the stress in the steel member remained relatively constant. However, when the thickness of the bearing plate is increased from 60 to 80 mm, the stress of each part of the steel plate in the steel grid will be significantly reduced, and the maximum reduction can reach 48%. The improvement of concrete strength has little effect on the stress of the steel cell, and the C50 concrete strength grade used in the design is more reasonable.

Experimental investigation on the performance of Cable-Girder anchorage structure of hybrid Cable-Stayed suspension bridges

As the key component of the stay cable connecting the girder and tower in the hybrid cable-stayed suspension system, the cable anchorage structure needs to bear the powerful cable force transmission function. Compared with normal anchorages, the structural features of a new type of anchor box structure cable-girder anchorage (CGA) that has strong bearing capacity and more uniform stress distribution for a long-span hybrid cable-stayed suspension bridge with steel box girder was investigated by a 1:2 scale specimen test and a series of finite-element analysis. Through finite element analysis (FEA) and test results, the stress distribution and cable load transfer pathway of anchor box structure are obtained. The test results show that the CGA design is reasonable and reliable. The four welds connected to the anchor box support plates and the steel box girder webs bear 87% of the cable force load transfer, and the remaining 13% of the cable load is delivered from the anchor box bearing plate to webs. A large stress concentration in the six welds, but the maximum von Mises stress (VMS) of welds is 130–151 MPa. According to the parametric studies,the installation angle of the anchor box considerably affects the stress characteristics. Also, the thickness and length of the anchor box plate are changed, the transmission and distribution proportion of the cable force between the main welds of the anchor box increase alternately.

A flexible bearing plate based on steel plate and rubber mat

The bearing plates used in plate load test for highway engineering are typically rigid. However, due to limitations in obtaining the accurate distribution of compressive stress at the bottom of the bearing plate, there is often a significant deviation between the measured subgrade resilient modulus and the actual condition. To address this issue, a flexible bearing plate can be used to test the subgrade and obtain a more accurate resilient modulus. In this study, we use variance and degree of mean deviation to quantitatively evaluate the distribution uniformity of compressive stress. To create a rigid-flexible bearing plate that is similar to a flexible bearing plate, we explore the combinatorial design of steel plates and rubber mats. We examine factors such as the thickness (10, 20, and 30 mm) of the steel plate, elastic modulus (5, 10, and 20 MPa) and thickness (10, 20, and 30 mm) of the rubber mat, friction coefficient (μ:0, 0,2, 0.4, 0.6, 0.8, ∞) between the bearing plate and subgrade, and the combined shape characteristics of the rubber mat and steel plate. To reduce friction between the rubber mat and subgrade, we use lubricant, and through our design process, we develop a flexible bearing plate with relatively uniform compressive stress. Our computations show that when μ = 0.05, the variance is 0.0001, and the degree of mean deviation is 0.0780. These results indicate that the distribution uniformity of the compressive stress is very close to the uniform distribution load, which meets the necessary accuracy requirements for engineering applications.

Weathering of Volcanic Rocks in Baturappe Formation and Its Implications for Foundation Planning of Pamukkulu Dam, South Sulawesi, Indonesia

The presence of weathered volcanic rocks in Pamukkulu area is important in determining the location and construction of the Pamukkulu main dam and plinth structure. In general, volcanic rocks have poor geotechnical characteristics due to varying degree of weathering, influence of groundwater, and systematic joints produced by cooling lava. This study aims to study the type and quality of weathered rock around the main dam and plinth area. First, mapping of surface geology was carried out. To evaluate the degree of weathering, rock resistivity data is used around the main dam area. Whereas for the plinth area, the bearing capacity of soil/rock is evaluated using Plate Bearing Test (PBT) and Standard Penetration Test (SPT). Bearing capacity obtained from PBT that were carried out on rock surface can be used to interpret rock weathering. In addition to SPT, the coring from rock drilling was also evaluated using Rock Quality Designation (RQD). It was found that the rock up to 20 m depth are of poor quality. It is recommended that the poor-quality rock is removed until moderately dense rock layer is found.

Crack Detection in Bearing Plate of Prestressed Anchorage Using Electromechanical Impedance Technique: A Numerical Investigation

The bearing plate is an important part of a tendon–anchorage subsystem; however, its function and safety can be compromised by factors such as fatigue and corrosion. This paper explores the feasibility of the electromechanical impedance (EMI) technique for fatigue crack detection in the bearing plate of a prestressed anchorage. Firstly, the theory of the EMI technique is presented. Next, a well-established prestressed anchorage in the literature is selected as the target structure. Thirdly, a 3D finite element model of the PZT transducer–target anchorage subsystem is simulated, consisting of a concrete segment, a steel anchor head, and a steel bearing plate instrumented with a PZT transducer. The prestress load is applied to the anchorage via the anchor head. The EMI response of the target structure is numerically obtained under different simulated fatigue cracks in the bearing plate using the linear impedance analysis in the frequency domain. Finally, the resulting EMI response was quantified using two damage metrics: root-mean-square deviation and correlation coefficient deviation. These metrics are then compared with a threshold to identify the presence of cracks in the bearing plate. The results show that the simulated cracks in the bearing plate are successfully detected by tracking the shifts in the damage metrics. The numerical investigation demonstrates the potential of the EMI technique as a non-destructive testing method for assessing the structural integrity of prestressed structures.

Dynamic analysis and vibration control for overhead hoist transport

The OHT system is a transport device used for intra- or inter-plant transport in a fab or other factory, the load-bearing part of the goods stored under the trolley generates longitudinal vibration and lateral oscillation due to inertia force When the OHT in the air starts or stops. Firstly, the trolley dynamic model under the action of lateral thrust and longitudinal tensile force need to be established. secondly, the coupling analysis of horizontal oscillation and longitudinal oscillation on the model is carried out. Thirdly, aiming at the lateral swing and longitudinal vibration of the carriage, a double closed-loop vibration control strategy with tension control as inner loop and speed control as outer loop and carry out the simulation analysis of longitudinal vibration control is proposed. In the experiment of the ground trolley, the control strategy is applied. The simulation and experimental results show that the control method can quickly restrain the longitudinal vibration of the trolley bearing plate, reduce the pulling force of the trolley on the lifting steel belt, and avoid the large displacement of the bearing plate in the air.

Dynamic monitoring of saturated stiff clay soil foundation structure by falling weight deflectometer system under impact loads sensors effect

Experiments research is done to determine how saturated stiff clayey soil responds to a single impulsive load. Models made of saturated, stiff clay were investigated. To supply the single pulse energy, various falling weights from various heights were tested using the falling weight deflectometer (FWD). Dynamic effects can range from the major failure of a sensitive sensor or system to the apparent destruction of structures. This study examines the response of saturated stiff clay soil to a single impulsive load (vertical displacement at the soil surface below and beside the bearing plates). Such reactions consist of displacements, velocities, and accelerations caused by the impact occurring at the surface depth induced by the impact loads and then recorded using the multi-recorder sensors. Using different factors, including soil surface, and the applied energies, the behavior of saturated stiff clay soil was investigated. Under the same impact loads (5 Kg) for both dropping elevations (250.00 mm and 500.00 mm), at soil surface level the average percent of change in the maximum impact forces generated in the contact surface increased by 41%, which resulted in a reduction of 34% in the maximum displacement reaction of the clay soil model.

Leaf‐Like TENGs for Harvesting Gentle Wind Energy at An Air Velocity as Low as 0.2 m s−1

AbstractExisting technologies for harvesting electrical energy from gentle wind face an enormous challenge due to the limitations of cut‐in and rated wind speed. Here, a leaf‐like triboelectric nanogenerator (LL‐TENG) is proposed that uses contact electrification caused by the damped forced vibration of topology‐optimized structure consisting of flexible leaf, vein bearing plate, and counterweight piece. The effectiveness of the topology‐optimized leaf‐like structure is studied, which solves the problem of reduced output due to electrostatic adsorption between the leaf surfaces while reducing the cut‐in (0.2 m s−1) and rated wind speed (2.5 m s−1). The LL‐TENG unit having small dimensions of 40 cm−2 (mass of 9.7 g) at a gentle wind of 2.5 m s−1 exhibits outstanding electrical performances, which produces an open‐circuit voltage of 338 V, a short‐circuit current of 7.9 µA and the transferred charge density of 62.5 µC m−2 with a low resonant frequency of 4 Hz, giving an instantaneous peak power of 2 mW. A distributed power source consists of the five LL‐TENGs in parallel is developed by designed self‐adaptive structure, for which the peak power output reaches 3.98 mW, and its practicability and durability are successfully demonstrated. This study is a promising distributed power source technology to drive electronics in gentle wind outdoor environments.

Utilization of concrete waste from demolition sites in pavement subgrade

The direct use of recycled waste concrete (RWC) is difficult as the demolished concrete shows large variation of raw materials and higher rate of water absorption due to the porosity of the lumps. Owing to such reasons, the utilization of the RWC is difficult for structural applications; however, it may be interesting to explore the feasibility of using RWC in non-structural applications such as subgrade layer of pavements. In this research work, the demolished concrete has been recycled with nominal crushing treatment in a ball mill and separated as fine powder, small to medium size aggregates. The soil samples have been prepared consisting soft clay (SC) type subgrade soil with all three forms of RWC in equal proportions. The SC has been replaced from 0% to 70% by weight with the blended RWC. Tests for the subgrade characterization namely California Bearing Ratio (CBR) values, dry density, moisture content, and plate load tests have been conducted. Under all test conditions, the addition of the RWC into the SC soil showed improvement at a given fraction of replacement. The work supported the feasibility of the utilization of the RWC for preparing the subgrade layer for the pavements and promoting the sustainability of the waste concrete in the civil engineering applications.

Finite element analysis of reinforced concrete deep beams with square web openings using damage plasticity model

This study investigates the behavior of RC deep beams with web openings based on the results of numerical simulations using the Abaqus/standard software. The numerical results of the validated specimens showed good agreement with the experimental ones. Then, the proposed concrete damage plasticity (CDP) model was used to examine the effect of various influential parameters, such as the shear span-to-height ratio (a/H), opening size, opening location, concrete compressive strength (fc'), main reinforcement ratio (ρs), and web reinforcement ratio (ρweb). It was found that the presence of openings impairs the bearing capacity of RC deep beams, especially openings with sizes of 0.3 and 0.4 of the overall height of the beam. Moreover, openings located through the shear zone significantly reduce the ultimate load, especially on the loading path and near the bearing plates. This is due to the high concentration of shear cracks at the corners of the openings through the loading path line. The behavior of RC deep beams with web openings mainly depends on the openings’ size and location. In addition, decreasing the shear span-to-height ratio increases the ultimate load. Meanwhile, increasing the concrete compressive strength (fc') increases the ultimate load. Similarly, increasing the main reinforcement ratio leads to a higher ultimate load due to adequate cracking control. The same finding can be revealed for the influence of the web reinforcement ratio on the bearing capacity of RC deep beams with web openings. Increasing the main reinforcement ratio from 0.45% to 0.57% and increasing the web reinforcement ratio from 0.29% to 0.33% can enhance the bearing capacity of RC deep beams by 11.36% and 3.26%, respectively. Finally, the numerical investigation reveals that the proposed simulated model can be used to effectively investigate the behavior of RC deep beams with openings overcoming their complexity.

Study of Mineralogy and Engineering Properties of Volcanic Rock at the Base of the Pamukkulu DAM Foundation, South Sulawesi, Indonesia

At the location of the Pamukkulu dam, it has engineering geological characteristics that are less supportive of the construction above it, especially for the foundation of the dam. By taking data directly in the field and by laboratory testing, information is needed regarding the characterization of mineralogy and the engineering properties of rocks. Mineralogical analysis was performed with petrography and X-Ray Diffraction (XRD) while the engineering properties of the rock were performed with Plate Bearing Tests (PBT), Standard Penetration Tests (SPT), and Rock Mass Rating (RMR). Based on mineralogical data, rocks have undergone weathering and converted the chemical-physical properties of minerals into porous, fine-grained minerals, forming mineral oxides as well as clay minerals. The carrying capacity of surface soils in the dam area based on the plate bearing test is relatively poor. As for subsurface rocks, the weight of the rock mass rating belongs to the class (II) Good to (III) Medium. Meanwhile, from the density value of hard soils, there are different depths from a depth of 1 meter to 6 meters. Weathering conditions of rocks affect the engineering value of soils and rocks where due to weathering minerals formed in the form of porous clay minerals, they are not well consolidated.

Hybrid tracer - A modified novel extra oral tracer.

Gothic arch Tracing has been a common modality in the recording of centric jaw relation. There has been two ways of recording the gothic tracing. They are extra oral and intra oral tracing. Among the extra oral tracers hight tracers are the most used tracers. Intra-oral and extra-oral tracers have a number of individual advantages and limitations. With the idea to overcome the short comings of both the tracers, hybrid tracers were made. Hybrid tracers could be a good alternative to the Hight-tracer in recording centric relation and can provide better clinical and teaching experience to the students. The hybrid tracer is a two-component assembly, upper and lower component. The upper component has a central bearing plate and stylus in continuation with the central bearing plate. The lower component has central bearing device with three central bearing points one anteriorly and two posteriorly, and it has a tracing platform (15×35mm) in continuation with the central bearing device. The length of these upper and lower components ismade to confine within the incisal rod of semi adjustable articulator. hybrid tracers showed more accuracy while recording the centric jaw relation. There was more stability and equalization of pressure during the movement due to a tripod effect of three screws. Hence it provided more precise recording and being less technique sensitive. It was also more comfortable and acceptable by the patient. hybrid tracers hence will provide more accuracy and precision in recording of horizontal jaw relation. This will in turn help in fabricating a successful prosthesis and enhance the well-being of the patient. This tracer will also be significant in institutions for educational purpose. Hybrid tracers are simple, non-technique sensitive, provide balance, equalization of pressure, stabilize the occlusal rims well, are close to the centre of rotation providing precise record and provide easy access and visibility to the operator which will help the operator in guiding the patient well for a correct jaw relation.

Short-term axial loading of continuous-flight pile segment in frozen soil

Research on the performance of continuous-flight piles for the use in permafrost is rare. In the present laboratory research, continuous-flight pile segments with 89 mm diameter and 300 mm length were installed in frozen soils and loaded under a constant displacement rate. The objectives were to investigate the load-transfer mechanism and the failure modes associated with the shaft resistance of the piles. Pile segments were screwed into a chamber filled with frozen soil and then loaded in the axial direction; installation torques and pile load resistance were measured, respectively, during the installation and loading stages. The effects of soil temperature, salinity, and water content on the short-term performance of these piles were examined. Results show that the pile capacities decreased with warming temperatures. The installation torque increased significantly as the soil temperature and salinity decreased. Cylindrical shearing mode (CSM) and individual bearing mode (IBM) of pile failure were observed at soil temperatures of −1 and −5 °C, respectively. Adfreeze and plate bearing resistance were determined under these failure modes. The global failure surface occurred at the edge of the threads under the CSM, and the shear resistance was increased along this surface. The existence of plate (i.e., flights) bearing resistance under the IBM suggests a potential advantage of continuous-flight piles over conventional smooth piles, because the plate bearing resistance is mobilized during loading.

Anchor plate bearing capacity in flexible mesh facings

This work addresses the problem of the loading capacity of an anchor plate coupled with a steel wire mesh in soil retaining applications. The interaction mechanism between the flexible mesh facing, the underlying soil layer and the plate is studied starting from the results of several laboratory punch tests involving both the plate and the mesh only, and the whole soil-mesh-plate system. The experimental tests have been reproduced by adopting a 3D discrete element model where also the wire mesh is discretized as an assembly of interconnected nodal particles. The interaction between these particles is ruled by elasto-plastic tensile force–displacement laws in which a distortion is introduced in a stochastic manner to account for the wires’ geometrical irregularities. The mesh model is then validated with reference to a set of punch tests in which the shape and size of the punching element as well as the nominal wire diameter were varied. Subsequently, the model is extended to a punch against soil test configuration permitting an insight into the nontrivial local mechanism between the mesh facing and the underlying granular layer. The good agreement between the numerical predictions and the experimental observations at the laboratory scale allowed us to extend the model towards more realistic field conditions for which the role of the mesh panel boundary conditions, the mesh mechanical properties, the soil mechanical properties and the anchor plate geometry is investigated.

Estimation of rock mass deformability based on empirical relations for Ghezel Ozan dam site in the north of Iran

Rock mass deformability modulus is one of the most important parameters for underground structures and dam site design. The current methods for determining this parameter are in situ tests and empirical equations. In situ tests are the best and most accurate methods and include plate bearing, flat jack and dilatometer tests. However, these in situ tests are difficult, time-consuming, expensive and sometimes even impossible. Therefore, many empirical equations have been developed to determine the rock mass deformability indirectly based on various parameters. In this study, the correlation between the deformation modulus values, rock mass rating (RMR) and tunnelling quality index ( Q ) classification has been studied for the Ghezel Ozan dam site in NW Iran. Then, empirical equations are used to calculate the rock mass deformation modulus ( E m ) based on dilatometer in situ tests and rock mass classifications as mentioned above are defined. Finally, the correlation between the equations given in this study and the empirical equations presented by other researchers based on RMR and TQI ( Q ) are also investigated using statistical indicators. According to this analysis, the equation estimated based on RMR has a good compliance with the equations presented by earlier researchers. Supplementary material: Supplementary datasets and figures are available at https://doi.org/10.6084/m9.figshare.c.6139108

Experiment and Validation of Local Bearing Capacity for Ultra-High-Performance Concrete Confined with Stirrups.

Ultra-high-performance concrete (UHPC) has the advantages of high compressive and tensile strength, high bending strength, good durability, remarkable corrosion resistance, and low self-weight. In this study, ten UHPC specimens were designed based on three fundamental parameters, including the ratio of the gross supporting area Ab to the bearing plate area Al (local area aspect ratio Ab/Al), the ratio of core area Acor to the bearing plate area Al (core area aspect ratio Acor/Al,), and the reinforcement ratio pv, to investigate mechanical behaviors and bearing capacity. Failure modes, cracking load, crack propagation, wedge features, the relationship between local compression and deformation, and the local bearing capacity was investigated. Finite element models (FEMs) were built to simulate and validate the observed behavior of the anchorage zone under compressive loading. The experiment results demonstrate that the pv significantly increases the bearing capacity. When the reinforcement ratio increased from 4.5% to 3.7%, the bearing capacity increased by 23%, and the effect of Acor/Al was not obvious. In addition, decreasing the Ab/Al from 11.1 to 6.3 increases the bearing capacity to 19%. Furthermore, a model was proposed to predict the bearing capacity of the UHPC specimens reinforced with stirrups. The calculated values, numerical predictions, and experiment results showed good agreement.

The Direct Strength Method for first generation trapezoidal steel sheeting under Interior One Flange and Interior Two Flange web crippling

Trapezoidal steel sheeting is a popular product in the built environment, especially for roofing and cladding. However, at a support the webs of the sheeting may fail due to concentrated force, referred to as web crippling. In this paper it is investigated whether the Direct Strength Method (DSM) can be used to predict this failure. First, an experimental programme, carried out in the past, is selected for its sheet section dimensions, materials, span lengths, and load bearing plate widths which were varied systematically. Two distinct failure mechanisms occurred: the yield arc and the rolling mechanisms. Based on the experiments, in this paper a finite element model is developed to simulate Interior One Flange (IOF) and Interior Two Flange (ITF) web crippling, and a very good correlation is obtained with the experiments. Subsequently, the simulations are used to predict the buckling load (via the first positive Eigenvalue), the yield load (via first plastic strains or stress extrapolation), and the ultimate load for each experiment and additional cases. In addition, for each failure mechanism, an existing theoretical model is used to predict the first order elasto-plastic mechanism initiation load. Six different DSM equations are calibrated for both IOF and ITF web crippling, using the above different buckling and yield loads. For IOF cases, the use of the IOF first positive Eigenvalue for the buckling load, and the first order elasto-plastic mechanism initiation load, results in the best correlation and coefficient of variation. For ITF cases, the ITF Eigenvalue and same yield load shows the best results. Excluding the rolling mechanism, the DSM correlates equally (IOF) or better (ITF) with the numerical results than the AISI S100-16 design rule. Thus, the DSM, as a generalized slenderness approach, is suited for IOF and ITF web crippling of first generation trapezoidal steel sheeting. Furthermore, it could be considered to allow for the use of the well performing FE models explicitly by the codes—e.g. enabling manufacturers to create tables of strength.

Distinguished punching shear behaviour of unbonded post-tensioned concrete slab – CFT column vs reinforced concrete slab – CFT column connections

This article evaluates and compares the punching shear behaviour of unbonded prestressed concrete (UPC) slab - concrete-filled steel tube (CFT) column connections/joints with that of reinforced concrete (RC) slab connection – CFT column connections. The experimental program was carried out on five large-sized samples, including three UPC slab - CFT column samples and two RC slab - CFT column samples. Steel plate connection details were utilised to increase the bond between the concrete slab and the CFT column. The experimental results showed that the prestressing tendons significantly increased the pre and post-cracking stiffness of the slab-column connections, thereby, greatly reducing the deflection of the UPC slab - CFT column samples than that of the RC slab - CFT column samples, especially during the serviceability phase (by up to 58%). However, the use of tendons resulted in a significant decrease in the ductility and energy absorption index of the UPC slab - CFT column samples compared to that of the RC slab - CFT column samples (by up to 44% and 41%, respectively). Using prestressing tendons slightly increased the punching shear capacity, and significantly reduced the strain of the connection details such as the vertical ribs and the horizontal bearing plate. At the same time, the tendons helped greatly reduce the strain of the longitudinal rebars in the UPC slabs.
 Keywords: Unbonded post-tensioned concrete (UPC); connection/joint; CFT column; flat slab; connection details; punching shear; experiment.