Improvement of a Truss-Reinforced, Half-Concrete Slab Floor System for Construction Sustainability

The truss-reinforced half-concrete slab has been widely used in prefabricated construction all over the world. It has become the most widely used prefabricated component form in China. However, its construction cost is higher than using the conventional construction method. To improve the half slab floor system, it is essential to have a comprehensive understanding of the truss-reinforced half slab’s structural performance over its complete loading history. Six experimental tests on such slabs were carried out. Three of them were reinforced with a steel bar truss (SBT) and the other three with a steel tube/bar truss (STBT). The steel tube in an STBT was grouted. The results show that when the specimen is damaged, the grouted steel tube does not undergo out-of-plane or in-plane buckling, and its force performance is good when compared to the steel bar in SBT. Compared with the SBT-reinforced slab specimens, the load characteristic values of the STBT-reinforced slabs were significantly improved, and the slabs had greater initial stiffness and resistance to deformation. Due to the fact that good structural performance of the steel tube was observed, after having studied the half slab component design, a dry, prefabricated, STBT-reinforced half slab system that can reduce the volume of concrete and amount of steel used in the present slab system is proposed. The proposed system has the advantages of allowing easier construction, cost reduction, and reuse of the components afterward to make the prefabrication construction more sustainable.

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Stiffness of Concrete-Filled Thin-Walled Steel Tubular Slender Columns

Civil and Environmental Engineering ◽

10.2478/cee-2021-0026 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Alireza Bahrami ◽

Ali Mahmoudi Kouhi

Keyword(s):

Uniform Distribution ◽

Experimental Tests ◽

Simulation Method ◽

Steel Tube ◽

Initial Stiffness ◽

Cross Sectional ◽

Circular Column ◽

Finite Element Software ◽

Thin Walled ◽

Slender Columns

Abstract Concrete-filled thin-walled steel tubular slender columns are studied in this paper to evaluate their stiffness. The slender columns have various steel tube thicknesses, length/diameter (width) ratios, and concrete compressive strengths. The columns are loaded by axial and eccentric loads. Two experimental tests of the slender and stub columns are described. Also, the finite element software ABAQUS is utilised to simulate and analyse the columns. The tested columns are simulated taking into account all their features in the tests to verify the simulation of the columns. The simulation results are compared with the tests results which reveal that good agreements exist between them. Thus, the proposed simulation method of the columns is verified. In order to assess the stiffness of the columns under different conditions, various load eccentricities (0 mm, 25 mm, and 50 mm), cross-sectional configurations (circular, rectangular, and square), and steel tube thicknesses (2 mm, 3.35 mm, and 5 mm) are adopted for the developed columns. The columns are simulated and analysed based on the verified simulation method considering the mentioned conditions. As a conclusion, the stiffness of the columns is generally reduced by the increase of the load eccentricity from 0 mm to 25 mm and 50 mm. Further, more uniform distribution of the stiffness is witnessed for the columns with lower eccentricities. In addition, the enhancement of the load eccentricity increased the reduction slope of the stiffness graph for the columns. Although the initial stiffness of the circular column is slightly lower than the rectangular and square columns, the stiffness has more uniform distribution which is preferred. Larger stiffness is achieved for the columns by increasing the steel tube thickness from 2 mm to 3.35 mm and 5 mm.

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Shear Resistance Capacity of Interface of Plate-Studs Connection between CFST Column and RC Beam

Mathematical Problems in Engineering ◽

10.1155/2017/9456768 ◽

2017 ◽

Vol 2017 ◽

pp. 1-13

Author(s):

Qianqian Wang ◽

Hua Ma ◽

Zhenbao Li ◽

Zhenyun Tang ◽

Haiyan Chen ◽

...

Keyword(s):

Shear Force ◽

Concrete Slab ◽

Theoretical Calculations ◽

Steel Tube ◽

Interfacial Shear ◽

Vertical Shear ◽

Structural Performance ◽

Steel Beam ◽

Rc Beam ◽

Shear Forces

The combination of a concrete-filled steel tube (CFST) column and reinforced concrete (RC) beam produces a composite structural system that affords good structural performance, functionality, and workability. The effective transmission of moments and shear forces from the beam to the column is key to the full exploitation of the structural performance. The studs of the composite beam transfer the interfacial shear force between the steel beam and the concrete slab, with the web bearing most of the vertical shear force of the steel beam. In this study, the studs and vertical steel plate were welded to facilitate the transfer of the interfacial shear force between the RC beam and CFST column. Six groups of a total of 18 specimens were used to investigate the shear transfer mechanism and failure mode of the plate-studs connection, which was confirmed to effectively transmit the shear forces between the beam and column. The results of theoretical calculations were also observed to be in good agreement with the experimental measurements.

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DESIGN AND PERFORMANCE OF HIGH-RISE STRUCTURE USING ULTRA-LIGHTWEIGHT CROSS LAMINATED TIMBER FLOOR SYSTEM

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.2020.7(2).str-29 ◽

2020 ◽

Vol 7 (2) ◽

Author(s):

Danish Ahmed ◽

Tahar Ayadat ◽

Andi Asiz

Keyword(s):

Concrete Slab ◽

Performance Criteria ◽

Structural Performance ◽

Lateral Loads ◽

Reinforced Concrete Slab ◽

Existing Building ◽

Cross Laminated Timber ◽

High Rise ◽

Rc Slab ◽

Floor System

The main objective of this paper is to study the structural performance of a high-rise structure when alternative lightweight material known as cross-laminated timber was used as a slab in floor system in lieu of conventional reinforced concrete slab. A numerical case study was conducted using a highly irregular RC frame building with its two 60-story towers joined at the top. Three major analyses were considered. First, modeling and analyzing the building with an RC slab was conducted to determine the design reference. Second, substituting the RC slab with the CLT slab was performed using the same building skeleton. Third, redesigning and optimizing the building skeleton with that CLT to observe skeleton material saving obtained using the same structural performance criteria. Major lateral loads applicable in the Eastern Province of Saudi Arabia were inputted. Strengths and serviceability requirements for floor diaphragm and lateral load resisting system were checked first before performing a comparative analysis between traditional RC and CLT slabs as floor diaphragm. The structural performance criteria to be used for comparative study between RC and CLT slabs included total drift, inter-story drift due to lateral loads, and base reactions. Structural periods and acceleration responses for each floor were investigated and contrasted with the existing building code. The foundation demand was also investigated based on the structural weight and reactions generated from the RC and CLT floor systems.

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Structural Performance Evaluation of CFT Columns with Built-up Square-shaped Steel Tubes using Production Methods

Korean Society of Hazard Mitigation ◽

10.9798/kosham.2020.20.6.39 ◽

2020 ◽

Vol 20 (6) ◽

pp. 39-46

Author(s):

U Seok Kim ◽

Sang Seup Kim ◽

Sung Bae Kim ◽

Young Han Choi

Keyword(s):

Compression Test ◽

Maximum Load ◽

Steel Tube ◽

Structural Performance ◽

Test Results ◽

Steel Tubes ◽

Production Methods ◽

Steel Bar ◽

Main Variable

This study obtained compression test results and macro examination results for concrete-filled steel tube (CFT) columns with built-up square-shaped steel tubes to evaluate both the structural performance and the possibility of using the current CFT design for changes in production methods. The CFT columns have three variables, namely, welding details, welding types, and steel bar types, of which welding details are the main variable. The compression test results were compared with the nominal compressive strength, Pn, based on the material test results and complete joint penetration (CJP). The test results indicated that the ratio of the experimental maximum load to the theoretical calculation result was between 1.04 and 1.12 (1.08 on average). This means that it is possible to use the current CFT design in the current Building Structure Standards (KBC 2016, KDS 41 31 00). The macro examination results indicated that the quality of welding will be improved owing to the minimization of defects during welding if the groove angle is improved to 50°.

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Experimental/Numerical Evaluation of Steel Trapezoidal Corrugated Infill Panels with an Opening

Applied Sciences ◽

10.3390/app11073275 ◽

2021 ◽

Vol 11 (7) ◽

pp. 3275

Author(s):

Majid Yaseri Gilvaee ◽

Massood Mofid

Keyword(s):

Energy Dissipation ◽

Ultimate Strength ◽

Steel Plate ◽

Shear Walls ◽

Experimental Results ◽

Structural Performance ◽

Initial Stiffness ◽

Infill Panels ◽

Energy Dissipation Capacity ◽

Ductility Ratio

This paper investigates the influence of an opening in the infill steel plate on the behavior of steel trapezoidal corrugated infill panels. Two specimens of steel trapezoidal corrugated shear walls were constructed and tested under cyclic loading. One specimen had a single rectangular opening, while the other one had two rectangular openings. In addition, the percentage of opening in both specimens was 18%. The initial stiffness, ultimate strength, ductility ratio and energy dissipation capacity of the two tested specimens are compared to a specimen without opening. The experimental results indicate that the existence of an opening has the greatest effect on the initial stiffness of the corrugated steel infill panels. In addition, the experimental results reveal that the structural performance of the specimen with two openings is improved in some areas compared to the specimen with one opening. To that end, the energy dissipation capacity of the specimen with two openings is obtained larger than the specimen with one opening. Furthermore, a number of numerical analyses were performed. The numerical results show that with increasing the thickness of the infill plate or using stiffeners around the opening, the ultimate strength of a corrugated steel infill panel with an opening can be equal to or even more than the ultimate strength of that panel without an opening.

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On-Site Experimental Testing to Study the Vibration of Composite Floors

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.601.231 ◽

2014 ◽

Vol 601 ◽

pp. 231-234

Author(s):

Cristian Lucian Ghindea ◽

Dan Cretu ◽

Monica Popescu ◽

Radu Cruciat ◽

Elena Tulei

Keyword(s):

Dynamic Characteristics ◽

Experimental Testing ◽

Concrete Slab ◽

Human Perception ◽

Experimental Tests ◽

International Standards ◽

Structural Element ◽

Element Analysis ◽

Floor Slabs ◽

Composite Floors

As a general trend, in order to reduce material consumption or to reduce the mass of the structures, composite floor slabs solutions are used to achieve large spans floor slabs. This solutions led to floors sensitive to vibrations induced generally by human activities. As a verification of the design concepts of the composite floors, usually, it is recommended a further examination of the floor after completion by experimental tests. Although the experimental values of the dynamic response of the floor are uniquely determined, the processing can take two directions of evaluation. The first direction consist in determining the dynamic characteristics of the floor and their comparison with the design values. Another way that can be followed in the processing of the experimental results is to consider the human perception and comfort to the vibration on floors. The paper aims to present a case study on a composite floor, with steel beams and concrete slab, tested on-site. Both aspects of data processing are analyzed, in terms of the structural element, and in terms of the effect on human perception and comfort. Experimentally obtained values for the dynamic characteristics of the floor are compared with numerical values from finite element analysis, while the second type of characteristic values are compared with various human comfort threshold values found in international standards.

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Research on Compression Behavior of Square Thin-Walled CFST Columns with Steel-Bar Stiffeners

Applied Sciences ◽

10.3390/app8091602 ◽

2018 ◽

Vol 8 (9) ◽

pp. 1602 ◽

Cited By ~ 9

Author(s):

Zhao Yang ◽

Chengxiang Xu

Keyword(s):

Bearing Capacity ◽

Local Buckling ◽

Steel Tube ◽

Steel Tubes ◽

Compression Behavior ◽

Steel Bar ◽

Steel Bars ◽

Thin Walled ◽

Structural Measure ◽

Cfst Columns

Local buckling in steel tubes was observed to be capable of reducing the ultimate loads of thin-walled concrete-filled steel-tube (CFST) columns under axial compression. To strengthen the steel tubes, steel bars were proposed in this paper to be used as stiffeners fixed onto the tubes. Static-loading tests were conducted to study the compression behavior of square thin-walled CFST columns with steel bar stiffeners placed inside or outside the tube. The effect and feasibility of steel bar stiffeners were studied through the analysis of failure mode, load–displacement relationship, ultimate load, ductility, and local buckling. Different setting methods of steel bars were compared as well. The results showed that steel-bar stiffeners proposed in this paper can be effective in delaying local buckling as well as increasing the bearing capacity of the columns, but will decrease the ductility of the columns. In order to obtain a higher bearing capacity of columns, steel bars with low stiffness should be placed inside and steel bars with high stiffness should be placed outside of the steel tubes. The study is helpful in providing reference to the popularization and application of this new structural measure to avoid or delay the local buckling of thin-walled CFST columns.

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