scholarly journals Experimental study on notched connectors for glulam-lightweight concrete composite beams

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 2171-2180
Author(s):  
Yuchen Jiang ◽  
Xiamin Hu ◽  
Wan Hong ◽  
Jun Zhang ◽  
Fangqian He
Keyword(s):  
Lightweight Concrete ◽  
Shear Fracture ◽  
Concrete Slab ◽  
Composite Beams ◽  
Shear Capacity ◽  
Major Influence ◽  
Structural Element ◽  
Diagonal Compression ◽  
Concrete Type ◽  
Shear Performance

A new type of structural element, the timber-concrete composite beam, exhibited excellent structural performance. The notched connector is widely used in timber-concrete composite systems as a result of its considerable shear capacity and stiffness. Six groups of push-out tests were performed to investigate the shear performance of the notched connectors for the timber-concrete composite beams, with consideration to the varying concrete types, the shear length of the timber, and whether the notch was reinforced. From the test results, the notched connectors that corresponded to the shear fracture of concrete or timber had a low shear capacity and poor ductility. Notched connectors that simultaneously failed at the concrete slab (via shear force), as well as at the lag screw reinforcement point during bending presented the greatest shear capacity. This was followed by the notched connectors that exhibited diagonal-compression failure at the concrete slab. Screw fasteners in the notch were shown to improve the strength, ductility, and post-peak behavior of the notched connectors. In addition, the concrete type, the shear length of the timber, and whether the notch was reinforced were found to have no major influence on the slip modulus of the notched connectors.

scholarly journals Longitudinal shear capacity of the slabs of composite beams

1976 ◽  
Vol 3 (4) ◽  
pp. 514-522 ◽  
Author(s):  
M. N. El-Ghazzi ◽  
H. Robinson ◽  
I. A. S. Elkholy
Keyword(s):  
Composite Beam ◽  
Shear Failure ◽  
Concrete Slab ◽  
Compressive Force ◽  
Longitudinal Shear ◽  
Composite Beams ◽  
Shear Capacity ◽  
Slab Width ◽  
Two Parameters ◽  
Concrete Elements

The longitudinal shear failure of the slab of composite beams is constrained to occur at a predetermined shear surface. A method for calculating the longitudinal shear capacity of the slab of simply-supported steel–concrete composite beams is presented. The method is based on analyzing the stresses at failure of the concrete elements located at the slab shear surface.A design chart based on estimating the transverse normal stress required within the concrete slab to achieve the full ultimate flexural capacity of the composite beam is proposed. Alternatively, using elastic–plastic stress distribution across the concrete slab, the longitudinal compressive force due to bending and hence the applied moment can be predicted for any longitudinal shear capacity of the slab. The proposed design and analysis when compared to previous tests and analysis showed good agreement.The slab width and the shear span of the composite beam are found to be two important parameters which cannot be neglected when estimating the longitudinal shear capacity of the slab. These two parameters have been neglected in the empirical solutions previously adopted.

Grout Injection Effect on the Shear Behavior of FRCM Strengthened Stone Masonry Panels

2019 ◽  
Vol 817 ◽  
pp. 552-559
Author(s):  
Francesca Ferretti ◽  
Andrea Incerti ◽  
Anna Rosa Tilocca ◽  
Claudio Mazzotti
Keyword(s):  
Shear Capacity ◽  
Stone Masonry ◽  
Masonry Structures ◽  
Compression Tests ◽  
Grout Injection ◽  
Structural Element ◽  
Diagonal Compression ◽  
Two Samples ◽  
Injection Effect

During the last decades, several seismic phenomena have shown the high vulnerability of existing stone masonry structures subject to horizontal actions. Innovative composite materials, such as Fiber Reinforced Cementitious Matrix (FRCM), can be adopted for the retrofitting of masonry structures. The use of these innovative FRCM systems is usually combined with a more traditional retrofitting technique: grout injection. It allows to restore or improve the transversal connection between wall leaves, ensuring a monolithic behavior of the structural element. The objective of this research was to analyze the effect of the quality of the grout injection on the shear response of FRCM strengthened stone masonry panels. Results from an experimental campaign, where stone masonry specimens were subject to diagonal compression tests, are therefore presented in this paper. Two samples were subject to grout injection and one of them was strengthened with Steel Reinforced Grout (SRG). Comparisons between the experimental results showed that grout injection alone, if correctly executed, could determine a significant improvement in the shear capacity of masonry panels. The application of the FRCM strengthening system could further enhance the behavior of the samples, especially influencing the failure mode. Comparisons with analytical formulations for the evaluation of the capacity of strengthened walls are also presented.

scholarly journals Shear Capacity of Open Sandwich Steel Plate-Concrete Composite Slab: Experimental and Analytical Studies

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Lili Wu ◽  
Lipei An ◽  
Jiawei Li
Keyword(s):  
Failure Mode ◽  
Shear Force ◽  
Steel Plate ◽  
Concrete Slab ◽  
Experimental Studies ◽  
Shear Capacity ◽  
Crack Model ◽  
Composite Slab ◽  
Finite Element Software ◽  
Shear Performance

Considering that the fixed crack model by default of the general finite element software was unable to simulate the shear softening behavior of concrete in the actual situation, a rotational crack model based on the modified compression field theory developed by UMAT (user material) of ABAQUS software was proposed and applied to the nonlinear analysis, and a numerical simulated model for the steel-concrete composite slab was built for shear analysis. Experimental studies and numerical analyses were used to investigate the shear load-carrying capacity, deformation, and crack development in steel plate-concrete composite slab, as well as the effects of the shear span ratio and shear stud spacing on the shear performance and the contribution of the steel plate and the concrete to the shear performance. Shear capacity tests were conducted on three open sandwich steel plate-concrete composite slabs and one plain concrete slab without a steel plate. The results indicated that the shear-compression failure mode occurred primarily in the steel plate-concrete composite slab and that the steel plate sustained more than 50% of the total shear force. Because of the combination effect of steel plate, the actual shear force sustained by the concrete in the composite slab was 1.27 to 2.22 times greater than that of the calculated value through the Chinese Design Code for Concrete Structures (GB 50010-2010). Furthermore, the shear capacity of the specimen increases by 37% as the shear stud spacing decreases from 250 mm to 150 mm. By comparing the shear capacity, the overall process of load deformation development, and the failure mode, it was shown that the simulation results corresponded with the experimental results. Furthermore, the numerical simulation model was applied to analyze the influence of some factors on composite slab, and a formula of shear bearing capacity of slab was obtained. The results of the formula agreed with the test result, which could provide references to the design and application of steel plate-concrete composite slab.

scholarly journals Study on Shear Behavior of Multi-Bolt Connectors for Prefabricated Steel–Concrete Composite Beams

2021 ◽  
Vol 8 ◽  
Author(s):  
Wei Wang ◽  
Xie-dong Zhang ◽  
Xi-long Zhou ◽  
Lin Wu ◽  
Hao-jie Zhu
Keyword(s):  
Mechanical Performance ◽  
Concrete Strength ◽  
Three Dimensional ◽  
Shear Stiffness ◽  
Element Model ◽  
Composite Beams ◽  
Shear Capacity ◽  
Construction Time ◽  
Shear Connectors ◽  
Shear Performance

Multi-bolt shear connectors (MBSCs), arranging bolts as a group in several rows, can be applied in prefabricated steel–concrete composite beams or bridges (SCCBs) to reduce the construction time and meet the requirements of sustainable development. The mechanical behavior of bolt shear connectors has been broadly investigated in recent years, but they were mainly focused on the normal arrangement. The shear performance of MBSCs is not consistent with that of the same number of single bolts. In this study, a three-dimensional (3D) finite element model (FEM) was developed to investigate the multiple bolts effect and its mechanical performance. Material non-linearities and the interactions among all components were included in the FEM. The accuracy and reliability of the proposed FEM were initially verified against the available push-out test results. The validated FEM further studied the load–slip relationship, shear capacity, and shear stiffness of the MBSCs. A parametric study was carried out to determine the effect of the bolt spacing, bolt row numbers, the concrete strength, and the bolt diameter on the shear performance of MBSCs. Based on the extensive parametric analyses, design recommendations considering the multiple bolts effect for predicting the shear resistance per bolt in multi-bolt connectors were proposed and verified.

scholarly journals Mechanical Behavior of Hybrid Connectors for Rapid-Assembling Steel-Concrete Composite Beams

2019 ◽  
Vol 5 (10) ◽  
pp. 2081-2092
Author(s):  
Senqiang Lu ◽  
Wei Zhao ◽  
Puge Han ◽  
Zhenyuan Hang
Keyword(s):  
Mechanical Behavior ◽  
Bearing Capacity ◽  
Concrete Slab ◽  
Composite Beams ◽  
Shear Capacity ◽  
Filling Material ◽  
Shear Connectors ◽  
Finite Element Software ◽  
Mortar Strength ◽  
Circular Holes

In order to achieve a kind of shear connector suitable for rapid-assembling steel-concrete composite beams, a new type of hybrid shear connectors is proposed, in which the concrete slab with prefabricated circular holes and the steel beam with welded studs are installed and positioned, and then epoxy mortar is filled in the prefabricated hole to fix the studs. To study the mechanical behavior of these hybrid connectors, test on 18 push-out specimens with different prefabricated circular holes are carried out. ABAQUS finite element software is adopted to verify the relationship between the numerical simulation and experiment, influences of the epoxy mortar strength and prefabricated circular holes diameter are studied. The results show that filling epoxy mortar in the prefabricated hole is beneficial to improve the stiffness and bearing capacity of the specimen; the change of epoxy mortar strength has a certain impact on the bearing capacity and stiffness of the hybrid connector; In the case of the same strength of the filling material, the size of the prefabricated circular holes diameter directly affects the stiffness and bearing capacity of the shear stud. The shear capacity equations proposed by considering the epoxy mortar strength and prefabricated holes diameter, and it has a wide applicability.

Nonlinear Simulation Analysis on Steel Concrete Composite Beam with Rubber Aggregate

2014 ◽  
Vol 1044-1045 ◽  
pp. 71-74
Author(s):  
Jing Ping Yang
Keyword(s):  
Energy Consumption ◽  
Crack Resistance ◽  
Composite Beam ◽  
Concrete Slab ◽  
Composite Beams ◽  
Shear Capacity ◽  
Element Analysis ◽  
Nonlinear Simulation ◽  
Steel Composite ◽  
Rubber Concrete

In order to investigate mechanics performance of rubber concrete steel composite beam, nonlinear analysis on four steel concrete composite beams with different amount of rubber has been carried out using finite element analysis software, and the influence of rubber concrete to mechanical properties of composite beam was explored. The results show that ductility, crack resistance of rubber concrete slab, shear capacity of shear connector for rubber concrete steel composite beam are improved significantly compared with ordinary steel concrete composite beams. Along with the increase of rubber content, the energy consumption of composite beams gradually increases, while the ultimate bearing capacity decreases with small amplitude. As a kind of green environmental protection material Rubber Aggregate concrete has the characteristics of good ductility, crack resistance is strong, energy consumption is obvious and good wear resistance.

scholarly journals Behavior of Steel- Lightweight Concrete Composite Beams with Partial Shear Interaction

2018 ◽  
Vol 26 (2) ◽  
pp. 20-34
Author(s):  
Fareed Hameed Majeed
Keyword(s):  
Lightweight Concrete ◽  
Concrete Slab ◽  
Composite Beams ◽  
Point Load ◽  
Steel Beams ◽  
Initial Stiffness ◽  
Normal Concrete ◽  
Simply Supported ◽  
Modes Of Failure ◽  
Analysis Theory

This experimental work along with an analyticalanalysis is investigated.The behavior of simply supported steel beams with lightweight and normal concrete slab that have the same compressive strengthand slump was studied. Eight specimens tested under mid-point load and analysis by plastic analysis theory. Four of composite beams havea steel I-section beam with normal concreteslab and the other four with lightweight concrete slab. Different degrees of shear interaction were considered (100% to 40%). It was observed that there are no essential differences between the modes of failure that appeared in the tested composite beams with normal and lightweight concrete. Also, it was notedthat there is a decrease in the initial stiffness and also in the ultimate strength of the composite beams when the concrete of the flanges for the tested specimens was replaced from normal to lightweight concrete for different degrees of shear connections.The analytical results for all tested beam specimens, except that with normal concrete and 100% degree of shear interaction, gave overestimate results compared with those of experimental results.

scholarly journals Testing and Prediction of Shear Performance for Steel Fiber Reinforced Expanded-Shale Lightweight Concrete Beams without Web Reinforcements

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1594 ◽  
Author(s):  
Xiaoke Li ◽  
Changyong Li ◽  
Minglei Zhao ◽  
Hui Yang ◽  
Siyi Zhou
Keyword(s):  
Steel Fiber ◽  
Lightweight Concrete ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Bending Test ◽  
Fiber Reinforced ◽  
Cracking Resistance ◽  
Shear Performance ◽  
Shear Cracking ◽  
Expanded Shale

In this paper, for a wide application of high-performance steel fiber reinforced expanded-shale lightweight concrete (SFRELC) in structures, the shear behavior of reinforced SFRELC beams without web reinforcements was experimentally investigated under a four-point bending test. Twenty-six beams were fabricated considering the influencing parameters of SFRELC strength, shear-span to depth ratio, longitudinal reinforcement ratio and the volume fraction of the steel fiber. The statistical analyses based on the foundational design principles and the experimental results are made based on the shear cracking resistance, the shear crack distribution and width, the mid-span deflection, the patterns of shear failure, and the shear capacity of the specimens. This confirms the effective strengthening of steel fibers on the shear performance of reinforced SFRELC beams without web reinforcements. Based on the modifications to the formulas of reinforced conventional concrete, lightweight-aggregate concrete or steel fiber reinforced concrete (SFRC) beams, and the validation against the experimental findings, formulas are proposed for the prediction of shear cracking resistance and shear capacity of reinforced SFRELC beams without web reinforcements. Finally, formulas are discussed for the reliable design of the shear capacity of reinforced SFRELC beams without web reinforcements.

scholarly journals The experimental investigations of RC internal columns in the connection zone with lightweight concrete slab

2013 ◽  
Vol 12 (1) ◽  
pp. 187-194
Author(s):  
Tadeusz Urban ◽  
Michał Gołdyn ◽  
Łukasz Krawczyk
Keyword(s):  
Lightweight Concrete ◽  
Concrete Slab ◽  
Concrete Strength ◽  
Variable Parameter ◽  
High Strength ◽  
Shear Capacity ◽  
Punching Shear ◽  
Experimental Investigations ◽  
Load Carrying Capacity ◽  
Load Carrying

This paper presents the problem of load carrying capacity of the columns made of high-strength reinforced concrete which are separated by slab made of lightweight concrete. The experimental investigations of three models representing the internal connection between column and flat slab made of lightweight concrete of the strength tree times less than concrete strength of column are presented. The effort degree on the punching shear capacity stands for the variable parameter in the presented study. The performed study shows that there is no effect of this parameter on the effective concrete strength of the column.

Theoretical and experimental research on slip and uplift of the timber-concrete composite beam

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 7079-7099
Author(s):  
Jianying Chen ◽  
Guojing He ◽  
Xiaodong (Alice) Wang ◽  
Jiejun Wang ◽  
Jin Yi ◽  
...  
Keyword(s):  
Differential Equations ◽  
Deformation Theory ◽  
Concrete Slab ◽  
Theoretical Calculations ◽  
Structural Element ◽  
Structural Efficiency ◽  
Theoretical Investigations ◽  
New Type ◽  
Interlayer Slip ◽  
Good Agreement

Timber-concrete composite beams are a new type of structural element that is environmentally friendly. The structural efficiency of this kind of beam highly depends on the stiffness of the interlayer connection. The structural efficiency of the composite was evaluated by experimental and theoretical investigations performed on the relative horizontal slip and vertical uplift along the interlayer between composite’s timber and concrete slab. Differential equations were established based on a theoretical analysis of combination effects of interlayer slip and vertical uplift, by using deformation theory of elastics. Subsequently, the differential equations were solved and the magnitude of uplift force at the interlayer was obtained. It was concluded that the theoretical calculations were in good agreement with the results of experimentation.

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