Search

Facing the insufficient shear-bearing capacity of Hollow Core Beam (HCB), the High-performance Concrete (HPC) and shear steel rebars were proposed by the authors. However, investigations of the maximum diagonal crack width of the strengthened HCB specimens were scarce. Simultaneously, there were no details for the shear failure mechanism of the complex interface between HCB and HPC. For this reason, the failure modes and stirrup stress were first investigated. A simple model of maximum diagonal crack width of the strengthened HCB specimens was suggested. The maximum deviation of predictive value and test result was within 3%. Secondly, a modified truss-arch model of strengthened HCB specimen was proposed, considering the tensile behavior of the HPC. The average ratio of estimated and experimental results was 1.02. Finally, the shear-bearing capacity of strengthened HCB specimens was suggested considering the shear contribution of the HPC, shear steel rebars and interface bonding force. Compared with the previous shear test results reported by the authors, the maximum deviation was within 1%. To validate the accuracy of the formula, the other HCB specimen was used to evaluate the maximum deviation within 5%. It can be concluded that the proposed formula agrees well with the test results. [ABSTRACT FROM AUTHOR]

The capacity of the circumferential joint of the precast concrete segmental tunnel lining (PCTL) structure in terms of shear performance principally includes the dowel action by connector/bolt as well as friction force, and it is a vital parameter to assess the mechanical response of the circumferential joint. Further, as there was no analytical model available for precise estimation of a circumferential joint in terms of the shear‐bearing capacity considering the dowel action of the bolt in the presence of axial/normal force, therefore in this investigation, an analytical model has been proposed to estimate the shear‐bearing capacity of the circumferential joint. Furthermore, the analytical model's precision and accuracy were validated via large‐scale experimental investigation on a circumferential joint of PCTL. Upon comparing analytical model outcomes with experimental results, absolute error varied between +5% and −9%, with an average value of the coefficient of friction at the yield point of the bolt. Moreover, the formation of hinges on the side of the bolt within the segment was considered a failure of the circumferential joint. Additionally, the parametric investigation revealed that with just a 1% change in axial force, the diameter, pre‐tightening, and yield strength of the bolt and concrete strength improved by 2.85%, 1%, 0.27%, 0.26% and 0.17% shear‐bearing capacity of the circumferential joint respectively. Axial force variation greatly influences the shear‐bearing capacity of circumferential joint followed by diameter, pre‐tightening, yield strength of the bolt, and concrete strength. Conclusively, with analysis of axial force distribution around the ring for the tunnel, the proposed model has been applied to a full ring to estimate shear bearing capacity. [ABSTRACT FROM AUTHOR]

In this study, three new types of demountable connections, consisting of reinforced concrete columns and steel beams, are proposed, and their seismic performance is investigated through the use of cyclic loading tests. The test results reveal that these three demountable RCS joints show good seismic performance, in which the ductility coefficients of specimens RCS-1 and RCS-2 are improved by 69% and 109%, respectively, compared with the reference group of RCS-0 specimens. Various parameters, such as the beam flange thickness, bolt strength, and connecting steel strength, were analyzed using the finite element software ABAQUS 2021 to determine the effect of these parameters on the seismic performance and behavior of the connections. The results also show that the three demountable RCS joints are very sensitive to the variation in beam flange steel thickness, while the connector steel strength and bolt type have very little effect on the joint load-carrying capacity. In addition, different current theoretical approaches for calculating the shear bearing capacity in the panel zone of joints are discussed. [ABSTRACT FROM AUTHOR]

The glubam (glue-laminated bamboo)-geopolymer concrete composite (BGCC) structure is a possible way to achieve sustainable construction due to its combination of renewable resources and industrial waste. This study combined glubam and geopolymer concrete in composite structures and investigated the shear behavior of BGCC structures with notched connections. Four groups of push-out tests were designed to evaluate the influence of the number of notches and screws on the slip modulus and shear capacity. The results showed that the composite structures with notched connections failed first due to shear cracking at the interface notch. The double-notch specimens increased the shear capacity by 54% compared to single-notch specimens. The shearing bearing capacity rose by 35% on average as a screw increased in a single notch. The ductility and slip modulus were influenced primarily by the screws, with each extra screw in a single notch increasing the slip modulus by 21% in each stage. Based on the test results, a modified formula was proposed to predict the shear-bearing capacity of notched connections in BGCC structures. This study provides comparison data for further studies in the long-term behavior of BGCC structures.

The glubam (glue-laminated bamboo)-geopolymer concrete composite (BGCC) structure is a possible way to achieve sustainable construction due to its combination of renewable resources and industrial waste. This study combined glubam and geopolymer concrete in composite structures and investigated the shear behavior of BGCC structures with notched connections. Four groups of push-out tests were designed to evaluate the influence of the number of notches and screws on the slip modulus and shear capacity. The results showed that the composite structures with notched connections failed first due to shear cracking at the interface notch. The double-notch specimens increased the shear capacity by 54% compared to single-notch specimens. The shearing bearing capacity rose by 35% on average as a screw increased in a single notch. The ductility and slip modulus were influenced primarily by the screws, with each extra screw in a single notch increasing the slip modulus by 21% in each stage. Based on the test results, a modified formula was proposed to predict the shear-bearing capacity of notched connections in BGCC structures. This study provides comparison data for further studies in the long-term behavior of BGCC structures. [ABSTRACT FROM AUTHOR]

In this study, three new types of demountable connections, consisting of reinforced concrete columns and steel beams, are proposed, and their seismic performance is investigated through the use of cyclic loading tests. The test results reveal that these three demountable RCS joints show good seismic performance, in which the ductility coefficients of specimens RCS-1 and RCS-2 are improved by 69% and 109%, respectively, compared with the reference group of RCS-0 specimens. Various parameters, such as the beam flange thickness, bolt strength, and connecting steel strength, were analyzed using the finite element software ABAQUS 2021 to determine the effect of these parameters on the seismic performance and behavior of the connections. The results also show that the three demountable RCS joints are very sensitive to the variation in beam flange steel thickness, while the connector steel strength and bolt type have very little effect on the joint load-carrying capacity. In addition, different current theoretical approaches for calculating the shear bearing capacity in the panel zone of joints are discussed.

In order to study the shear mechanical properties of photovoltaic bracket member connection with the high⁃strength cold⁃formed thin⁃walled steel, 24 photovoltaic bracket connection specimens were tested for shear capacity. The mechanical properties of web and flange connected by bolts were mainly studied. The failure process and failure mode of the specimens were observed, and the load⁃displacement curve and ultimate bearing capacity of the specimens were obtained. The results show that when the peak load is reached, the self⁃drilling screw on the flange of the specimen is cut first, and then the cold⁃formed thin⁃walled steel plate near the bolt is compressed to yield, which leads to the typical bearing failure of the specimen. Compared with the specimen of the bolt on the flange, the stiffness of the specimen of the bolt on the web is larger, but the ductility is lower.Based on the relevant calculation formulas in the technical code, a modified calculation formula for calculating the bearing capacity of photovoltaic bracket member connection with the high⁃strength cold⁃formed thin⁃walled steel was proposed, and the calculation values were in good agreement with the test values. The research conclusion can provide reference for the engineering application of the photovoltaic bracket with the high⁃strength cold⁃formed thin⁃walled steel. [ABSTRACT FROM AUTHOR]

Faced with serious tensile–shear fracturing of anchor bolts and cables in deep roadways, it is of great significance to investigate Anchor Cable with C-shaped tube (ACC), a combined structure of a C-shaped tube and an anchor cable with high strength and shear resistance. The shear mechanical properties of the anchor cable and ACC are systematically investigated using the technical means of theoretical analysis and double-shear tests. The improved equipment for a double-shear test not only considers the initial normal stress but also ensures the continuity of the anchor cable's axial force transmission while considering the influence of the inclination angle on the shear performance of supporting components. The research indicates that the C-shaped tube inhibits the occurrence of stress concentration near the joint surface and improves the stress state of the anchor cable, transforming its failure mode from tensile–shear failure to tensile failure. Compared with the anchor cable, ACC has a higher shear capacity, greater shear stiffness and better ductility in the shear direction. The shear capacity of ACC is higher when it is perpendicular to the joint plane than when inclined to 80°, and the shear capacity of the joint plane is linear with the initial normal stress. Two methods were proposed to contrast the shear capacity between the anchor cable and ACC, including the shear capacity of supporting components and the shear capacity of the joint surface. The former is to evaluate the shear capability of the anchor cable and ACC, while the latter is to evaluate the ability of the anchor cable and ACC to control the shear deformation of the joint surface. The tests results show that the average shear capacity of ACC is 279 kN higher than the anchor cable, with an average increase of 34.9%. The average shear capacity of the joint surface anchored by ACC is 306 kN higher than the anchor cable, with an average increase of 25.2%. ACC can effectively improve the shear capacity of the anchor cable in the free section and has wide application prospects. [ABSTRACT FROM AUTHOR]

The paper investigates the shear mechanic performance of transformed triangular corrugated steel plates (TT-CSPs) with top stringers applied in the trestle, incorporating a comprehensive analysis of how plate dimensions and corrugation density affect both elastic and inelastic buckling capacities. By proposing and validating formulas for the ultimate shear-bearing capacity through finite element analysis (FEA), this paper advances a capacity prediction approach that accounts for the finite rigidity of top stringers by introducing a reduction factor. The results reveal that corrugation density significantly impacts both elastic buckling load and ultimate strength, with plate width playing a more crucial role than height in determining capacity. Furthermore, the inclusion of top-stringer flexural rigidity is shown to notably enhance the shear-bearing capacity of TT-CSPs, providing a vital consideration for their strength design. [Display omitted] • Proposed formula for global elastic shear buckling load of transformed triangular corrugated steel plates (TT-CSP) • Proposed a comprehensive design method to predict shear-bearing capacity of TT-CSPs, considering top stringer constraints • Study the impact of corrugated plate and corrugation dimensions on elastic and inelastic buckling capacity of TT-CSPs • Reveal the contribution of top stringers to shear resistance of built-up TT-CSPs [ABSTRACT FROM AUTHOR]

In order to quantitatively evaluate the shear-bearing capacity of shear connectors of square concrete filled steel tube (CFST), push-out tests on 14 square CFSTs with shear connectors have been carried out. Among the 14 CFSTs, there are 13 specimens with steel plate connectors and one specimen with steel bar connectors. The following factors are investigated to figure out their influences on the performance of CFSTs, which are the width to thickness ratio of steel tube, thickness of steel plate, length of steel plate, strength of concrete, welding condition of steel plate, number of steel plate layer and interlayer spacing. The test results show that the ultimate bearing capacity and the elastic stiffness increase with decreasing width to thickness ratio of the steel tube, and increasing thickness and length of the steel plate. With increasing concrete strength, the ultimate bearing capacity also increases. However, the welding condition has no effect on the ultimate bearing capacity. The ultimate bearing capacity of the CFST with double-layer steel plate is greater than that with single-layer steel plate. The ultimate bearing capacity of steel bar type shear connector is 87% greater than that of the steel plate type shear connector, and the steel bar specimen shows good ductility. A formula for calculating the shear-bearing capacity of shear connectors has been developed, and the calculated shear-bearing capacities are in good agreement with the test data. [ABSTRACT FROM AUTHOR]

In der Bauindustrie hat der Einsatz von Fertigteilen viele Vorzüge gegenüber Ortbeton. Im Rahmen dieses Beitrags wird die Ausbildung des stumpfen Stoßes bei Fertigteilstützen betrachtet, die einer erhöhten Horizontalbeanspruchung ausgesetzt sind. In einem Rechenbeispiel werden verschiedene repräsentative Beanspruchungen für eine Geschossstütze näher untersucht und die Widerstände einer Stütze sowie einer stumpfen Stoßfuge mit Stahlplatte gegen Querkräfte dargestellt. Durch die Ableitung eines zulässigen Grenzverhältnisses HEd/ NEd werden die kritischen Lastfälle für die Stumpfstoßausbildung aufgezeigt. Es wird abgegrenzt, unter welchen Parametern nicht die Fugenschubtragfähigkeit, sondern die Querkrafttragfähigkeit innerhalb des Bauteils bemessungsmaßgebend wird. Zusätzlich wird ein alternativer Modellansatz für eine sehr glatte Stützenfuge vorgeschlagen und durch eine Bemessungstabelle anwenderfreundlich ausgewertet. A contribution to the investigation of the shear-bearing capacity of butt-jointed prefabricated columns with particular regard to an extraordinary impact load The use of pre-fabricated concrete elements has special advantages for the building industry. In this paper the butt-joint connection of prefabricated reinforced concrete columns under high horizontal stresses is focused. A calculation example demonstrates the representative loading cases and the shear design of a butt-jointed concrete column with a steel plate. Additionally it is differentiated under which situations not the shear bearing capacity of the joint but of the concrete element is decisive for the design. By determining an allowable maximum ratio HEd/ NEd the critical loading scenarios are shown and an alternative design model for very smooth column joints is presented and evaluated in an user-friendly chart. [ABSTRACT FROM AUTHOR]