scholarly journals Performance of Hollow Core Concrete Slab reinforced by embedded steel tubes

2019 ◽  
Vol 26 (4) ◽  
pp. 17-21
Author(s):  
Yousif Dhari Awad ◽  
Ali Hussein Ali Al-Ahmed
Keyword(s):  
Cross Section ◽  
Concrete Slab ◽  
Load Capacity ◽  
Concrete Slabs ◽  
Total Width ◽  
Horizontal Distance ◽  
Hollow Core ◽  
Steel Tubes ◽  
Ultimate Load Capacity ◽  
Core Concrete

The aims of this paper are gaining additive knowledge about using steel tubes as reinforcement for hollow-core concrete slabs. For this purpose, this paper presents an investigation of how one-way concrete slabs would behave after embedding steel tubes within the cross section. Five concrete slabs were cast, these specimens differ from one another in the horizontal distance (spacing) between the two steel tubes placed within its cross section, steel tubes positioned in the center of the shorter lane of the specimen (width) which is 400 mm, the steel tubes spaced from each other with 4 different configurations, they were 0, 100, 200 and 300 mm. The ratio of the clear spacing between the two tubes and to the total width of the specimen is indicated (s/b) equal to (0, 0.25, 0.5 and 0.75). In addition to one solid slab cast and tested as a reference for the testing results. All five concrete slabs were loaded up to failure by submitting load at one point at the center of the slab. Only one variable was deemed to be considered and checked on this study which is the (s/b) ratio defined earlier. The results exhibit that, using steel tubes as reinforcement increase the first crack load by 12.75% compared to the reference slab, as well as increasing the ultimate load capacity by 59.02% compared to the reference slab. As for the mid-span deflection, the specimens with steel tubes embedded decreased the deflection values up to 47.37 %.

Experimental Study on the Flexural Behavior of Hollow Core Concrete Slabs

2016 ◽  
Vol 857 ◽  
pp. 107-112 ◽  
Author(s):  
L.V. Prakashan ◽  
Jessymol George ◽  
Jeena B. Edayadiyil ◽  
Jerin M. George
Keyword(s):  
Experimental Study ◽  
Flexural Strength ◽  
Failure Load ◽  
Concrete Slab ◽  
Flexural Behavior ◽  
Concrete Slabs ◽  
Control Specimen ◽  
Hollow Core ◽  
The Past ◽  
Core Concrete

Hollow core concrete slabs have many advantages over the conventional solid concrete slabs. The flexural behavior of this type of slabs have not been investigated in detail in the past. The study here addressed this issue by conducting experimental study of four different hollow core concrete slabs along with a solid concrete slab as a control specimen. The load deflection curves were obtained along with the failure load and deflection at the first crack. The effectiveness of the conventional flexural capacity equation in predicting the capacity of hollow core slabs was evaluated. The results from the experimental study were also utilized to do a comparative study among the specimens studied. The study concluded that the conventional flexural strength equation can be used for hollow core slabs too and they have better performance than solid concrete slabs both in terms of load - deflection behavior and serviceability.

scholarly journals FIRE RESISTANCE PROVIDING OF HOLLOW‐CORE CONCRETE SLABS USING SHEET BUILDING MATERIALS

Fire Safety ◽  
2019 ◽  
pp. 72-77
Author(s):  
A. A. Renkas
Keyword(s):  
Heat Transfer ◽  
Fire Resistance ◽  
Material Properties ◽  
Concrete Slab ◽  
Radiation Heat Transfer ◽  
Temperature Fields ◽  
Concrete Slabs ◽  
Hollow Core ◽  
Radiation Heat ◽  
Core Concrete

Introduction. This paper deals with the analysis of world experience in fire resistance providing of hollow‐core concrete slabs. To protect concrete structures are used many structural applications: thermal coatings and materials. The research first analyzes main methods and hypothesis using to make temperature analysis of solution fire resistance of concrete structures. Problem of making temperature analysis of hollow‐core concrete slabs are nonlinear thermal material properties and radiation heat transfer in the hollow-cores. The aim of this paper is to establish the temperature distribution in hollow‐core concrete slab considering radiation heat transfer in the hollow-cores in case of fire in compartment that is spreading by standard temperature-time curve. In addition, the aim is to substantiate the possibility of using gypsum panels to provide fire resistance of hollowcore concrete slabs. Material statement. The paper reports the results of modeling the process of heat transfer in hollow‐core concrete slab, between compartment space and slab surface and in hollow‐cores. To calculate temperature fields in hollow‐core concrete slab considering nonlinear thermal material properties and radiation heat transfer in the hollow-cores was used finite element model. At addition, the results of finite elements simulations show temperature fields in hollow‐core concrete slab and gypsum panels that installed under concrete slab. Scientific novelty. The paper reports results of theoretic substantiated of possibility of using gypsum panels to protect of hollow‐core concrete slabs considering nonlinear thermal material properties, radiation heat transfer between surfaces and radiation heat transfer in the hollow-cores. The results indicate that using gypsum panels to protect of hollow‐core concrete slabs reduces speed heating of concrete elements to critical temperatures that increase fire resistance of hollow‐core concrete slabs to 20.4 %.

Theoretic-Strength Concept of a Model Describing the Destruction of the Corner Part of a Slab-Column Structure

2015 ◽  
Vol 240 ◽  
pp. 225-231 ◽  
Author(s):  
Mirosław Wieczorek
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Laboratory Tests ◽  
Concrete Slab ◽  
Load Capacity ◽  
Limit Load ◽  
Traditional Theory ◽  
Load Step ◽  
Reinforced Concrete Slab ◽  
Column Structure

The paper presents a proposed theoretical-strength destruction model of the corner of a slab-column structure at 1:2 scale. The theoretical destruction model was developed on the basis of laboratory tests of a reinforced concrete slab with the dimensions 4000×4000×100 mm. The assumptions of the proposed theoretical model were based on a traditional theory of behaviour of reinforced concrete constructions. The method for calculating the strength of reinforced concrete sections is based on interaction graphs of the load capacity NRd, MRd,x and MRd,y. The calculation method takes into account the influence of changes in the shape of the cross-section of the analysed element on its limit load capacity in every load step.

Ultimate Bearing Capacity of Composition Columns Reinforced with the Prefabricated SHSCUS Filled with Steel Tubes Subjected to Axial Load

2011 ◽  
Vol 368-373 ◽  
pp. 225-229
Author(s):  
Guo Can Chen ◽  
Zhi Sheng Xu ◽  
Zhi Shuo Yang
Keyword(s):  
Bearing Capacity ◽  
Load Capacity ◽  
High Strength ◽  
Ultimate Bearing Capacity ◽  
Concrete Cover ◽  
Design Rule ◽  
Superposition Method ◽  
Steel Tubes ◽  
Ultimate Load Capacity ◽  
Concrete Type

This paper presents an experimental investigation on the short composition columns reinforced with the prefabricated super high strength concrete used stone-chop(abbreviated to SHSCUS) filled with steel tubes with 1RC as reference. The experimental parameters were the concrete type inner steel tubes, and L/D ratio, steel ratio and so on. The performance of the composition columns was investigated using different diameter-to-thickness ratio of steel tubes ranging from 15 to 26.6, and different cubic strength of 126.7, 120.3, 122.4, 134.4, 125.4, 111.4, 108.6MPa of infill concrete. The experimental results showed that concrete cover falling off was prior to specimens failure, and that the design rule, as specified in current code suitable for HSC overestimate the ultimate bearing capacity, were not suitable for the case with SHSCUS. Then the hypothesis was put forward based on experimental phenomena observed, and the formula of its ultimate load capacity was suggested based on superposition method, by which the predicted values have a good coincidence with those from the experiments.

Research on the Load Capacity of Separation Concrete-Filled Steel Tubes Subjected to Eccentric Compression on Separation Side

2010 ◽  
Vol 168-170 ◽  
pp. 632-636 ◽  
Author(s):  
Xia Ping Liu ◽  
Shu Tang ◽  
Chun Hui Tang ◽  
Zuo Yong Yang ◽  
Zuo Sun
Keyword(s):  
Ultimate Load ◽  
Load Capacity ◽  
Eccentricity Ratio ◽  
Steel Tubes ◽  
Ultimate Load Capacity ◽  
Short Columns ◽  
Separation Ratio ◽  
Eccentric Compression ◽  
Experimental Parameters ◽  
Concrete Filled Steel Tubes

This paper deals with the ultimate load capacity test on 14 short columns of separation concrete-filled steel tubes (CFST) which are subjected to the eccentric compression on separate side. The experimental parameters include the separation ratio and the eccentricity ratio. The result shows that the separation ratio and the eccentricity ratio will influence the load capacity of the components of the concrete-filled steel tubes which are subjected to the eccentric compression. The confinement of steel tubes to core concrete will be continuously weakened and the ultimate load capacity of the components will be decreased obviously with both the separation ratio and the eccentricity ratio increasing gradually.

scholarly journals Enhancing the Punching Load Capacity of Reinforced Concrete Slabs Using an External Epoxy-Steel Wire Mesh Composite

Fibers ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 68
Author(s):  
Abdulkhaliq A. Jaafer ◽  
Raid AL-Shadidi ◽  
Saba L. Kareem
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Load Capacity ◽  
Steel Wire ◽  
Wire Mesh ◽  
Concrete Slabs ◽  
Reinforced Concrete Slab ◽  
Concentrated Load ◽  
Reinforced Concrete Slabs ◽  
Steel Wire Mesh

The present experimental work investigates the applicability and performance of a new strengthening method for concrete slabs, intended to increase their punching resistance using combination layers of steel wire mesh with epoxy attached to the concrete slabs’ tension face. Six simply supported square reinforced concrete slab specimens were tested up to failure under a central concentrated load. The main parameters in the study are the concrete compressive strength (30 MPa and 65 MPa) and the configuration of a bundle externally fixed to the tension side of the tested slabs. The experimental results appeared to greatly enhance the performance of the specimens, as they were externally strengthenined under this new method. When compared to the control slabs, the punching load and stiffness of the strengthened slabs increased up to 28% and 21%, respectively.

scholarly journals The calculation of anchors in steel-concrete overlaps with precast slab

2019 ◽  
Vol 97 ◽  
pp. 06022
Author(s):  
Alexander Tusnin ◽  
Alexey Kolyago
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Concrete Slab ◽  
Element Model ◽  
Calculation Model ◽  
Concrete Slabs ◽  
Steel Beams ◽  
Steel Beam ◽  
Practical Application ◽  
Reinforced Concrete Slabs

Reinforced concrete floors and steel beams are widely used in buildings and structures for various purposes. Reinforced concrete overlaps can be cast-in or precast of hollow-core slabs. The most effective floors in which the concrete slab is located in the compressed area of cross-section, in steel beams in the tension zone, and shifting forces, arising between concrete slab and the steel beam, are perceived by anchors. Precast slabs in comparison with cast-in ones have less labor-intensive performance, the beam spacing is equal to the span of reinforced concrete slabs, there are no intermediate beams in such overlaps, that allows to reduce the floor thickness. The inclusion of precast in steel-concrete cross-section requires joints with steel beams, which requires using of special anchors. Anchor perceives shear forces and ensures the joint operation of the plate and the steel beam. In addition, for beams with narrow flange, the anchor device can provide the required width of the support slabs. The calculation of the attachment points of the anchors to the steel beam is carried out using three variants of calculation methods, which allow to determine the forces acting on the anchor. For practical application, a wire-element model has been proposed and managed to get forces in a steel beam, slab and anchors the width of the slab recommended by the standards should be included in the calculation model.

Flexural Behaviour of Reinforced Slab Panel System with Embedded Cold-formed Steel Frames as Reinforcement

2015 ◽  
Vol 74 (4) ◽  
Author(s):  
Cher Siang Tan ◽  
Yee Ling Lee ◽  
Shahrin Mohammad ◽  
Siong Kang Lim ◽  
Yeong Huei Lee ◽  
...  
Keyword(s):  
Concrete Slab ◽  
Load Capacity ◽  
Precast Concrete ◽  
Steel Frames ◽  
Control Sample ◽  
Steel Frame ◽  
Ultimate Load Capacity ◽  
Hollow Section ◽  
Average Value ◽  
Cold Formed Steel

This paper presents the experimental investigation on flexural characteristic of slab panels with embedded cold-formed steel frame as reinforcement. Perforated cold-formed steel channel sections are formed into steel frames as replacement to the conventional reinforcement bars inside precast concrete slab panels. A series of six experimental specimens for precast slab panels were tested. The specimens with 3 configurations namely control sample (CS) with conventional reinforcement bars, single horizontal C-channel section (SH) and double horizontal C-channel sections (DH) formed into rectangular hollow section. Results show that the tested slab specimens failed at the flexural crack at mid-span, under loading point and shear at the support. Tearing of shear connector in the cold-formed steel section was found to be the main factor for the structural failure. SH specimens achieved the highest ultimate load capacity, with average value of 138.5 kN, followed by DH specimens, 116.5 kN, and the control samples, 59.0 kN. The results showed that the proposed reinforced slab panel with embedded cold-formed steel frame was more effective compared to conventional reinforced slab.

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