Study of composite steel-concrete beams under negative bending moment

2022 ◽  
Author(s):  
Ali Hussam Ali ◽  
Hayder Wafi Ali Al-Thabhawee
Keyword(s):  
Concrete Beams ◽  
Bending Moment ◽  
Negative Bending ◽  
Composite Steel

scholarly journals About the use of semi-continuity to remove fireproof coatings in simply supported composite steel and concrete beams

2018 ◽  
Vol 11 (2) ◽  
pp. 296-306
Author(s):  
L. C. ROMAGNOLI ◽  
V. P. SILVA
Keyword(s):  
Lower Cost ◽  
Concrete Beams ◽  
Local Buckling ◽  
Bending Moment ◽  
Composite Beams ◽  
Design Code ◽  
Simply Supported ◽  
Additional Procedure ◽  
Composite Steel ◽  
Fire Conditions

Abstract The behavior under fire conditions of composite steel and concrete beams, not subjected to local buckling (compact steel profile), was studied considering the support rotational stiffness provided by the upper longitudinal slab reinforcement, usually present by means of anti-cracking meshes, and restriction of the steel profile’s lower flange, additional procedure required for development of the support bending moment resistance. Usually composite beams at room temperature are designed as simply supported and the semi-rigidity provided by this longitudinal reinforcement, if considered under fire conditions, may lead to a lower cost solution for fire protection of composite beams. The purpose of this study is to verify the viability of this proposal, using simplified design code methods.

Anchorages of stirrups under transverse tension in concrete - development of a design model

2019 ◽  
Author(s):  
Mirhat Medziti ◽  
Daia Zwicky
Keyword(s):  
Crack Width ◽  
Concrete Beams ◽  
Tensile Force ◽  
Concrete Structures ◽  
Experimental Tests ◽  
Reinforced Concrete Beams ◽  
Design Model ◽  
Hook Effect ◽  
Internal Forces ◽  
Negative Bending

<p>According to Swiss code SIA 262 "Concrete structures", stirrups of reinforced concrete beams must "surround the tensile longitudinal reinforcement" and must "be anchored to mobilize the static height of internal forces". For existing concrete structures, Swiss code SIA 269/2 provides stirrup detailing requirements while limiting these directives for stirrup anchorage to the compression zone. In zones of negative bending, these requirements are often not satisfied for execution reasons. This question is addressed in a largely experimental Ra&amp;D project. Anchorage tests were performed and analyzed, with a total of 144 tests on 9 concrete beams. These underwent a longitudinal tensile force up to 1’000 kN to simulate transverse cracking at stirrup anchorages in negative flexure zones. The study parameters are crack width (0, 0.4 and 0.9 mm), stirrup diameter (10 and 14 mm), bar ribbing (smooth and ribbed) and hook angle (90°, 135°, 180° and straight bars). A design model based on the "tension chord model" (TCM) developed at ETH Zurich is proposed. This simple and practical design model has proved ist effectiveness to consider bond effects. Reduction factors for bar diameter (k<sub>Ø</sub>), relative bar ribbing (k<sub>fR</sub>), hook effect (k<sub>θ</sub>) and crack width (k<sub>w</sub>) were taken into account for calibration. Results of analytical calculations are coherent with experimental tests.</p>

Analysis on Deformation of Pre-Splitting Steel Reinforced Concrete Beams Strengthened by Prestressed CFRP

2011 ◽  
Vol 243-249 ◽  
pp. 929-933
Author(s):  
Na Ha ◽  
Lian Guang Wang ◽  
Shen Yuan Fu
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Concrete Beams ◽  
Bending Moment ◽  
Reinforced Concrete Beams ◽  
Steel Reinforced Concrete ◽  
Cfrp Sheets ◽  
Deformation Curves ◽  
Prestressed Cfrp Sheets ◽  
Theoretical Results

In order to improve the bearing capacity of SRC which is related with deformation and stiffiness, SRC beams should be strengthened by CFRP. Based on the experiment of six pre-splitting steel reinforced concrete beams strengthened with (Prestressed) CFRP sheets, the deformation of beams are discussed. Load-deformation curves are obtained by the experiment. Considering the influence of intial bending moment on SRC beams, the calculated deformation formulas of SRC beams strengthened by (Prestressed) CFRP are deduced. The results showed that the load-deformation curves of normal and strengthened beams respectively showed three and two linear characteristics. The theoretical results which calculated by the formulas of deformation are well agreement with the experimental results.

scholarly journals Influence of stirrup spacing on shear resistance and deformation of reinforced concrete beams

2018 ◽  
Vol 7 (1) ◽  
pp. 126
Author(s):  
Latha M S ◽  
Revanasiddappa M ◽  
Naveen Kumar B M
Keyword(s):  
Concrete Beam ◽  
Concrete Beams ◽  
Bending Moment ◽  
Maximum Load ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Cement Concrete ◽  
Simply Supported ◽  
Reinforced Cement ◽  
Flexural Reinforcement

An experimental investigation was carried out to study shear carrying capacity and ultimate flexural moment of reinforced cement concrete beam. Two series of simply supported beams were prepared by varying diameter and spacing of shear and flexural reinforcement. Beams of cross section 230 mm X 300 mm and length of 2000 mm. During testing, maximum load, first crack load, deflection of beams were recorded. Test results indicated that decreasing shear spacing and decreasing its diameter resulted in decrease in deflection of beam and increase in bending moment and shear force of beam.

scholarly journals The influence of reinforcement temperature on stiffness of reinforced concrete beams in fire conditions

2013 ◽  
Vol 12 (1) ◽  
pp. 115-122
Author(s):  
Michał Głowacki ◽  
Marian Abramowicz ◽  
Robert Kowalski
Keyword(s):  
High Temperature ◽  
Cross Section ◽  
Static Load ◽  
Concrete Beams ◽  
Bending Moment ◽  
Reinforced Concrete Beams ◽  
Temperature Influence ◽  
Calculation Results ◽  
Tensile Zone ◽  
In Fire

This paper describes the analysis of high temperature influence on beams with heated tensile zone. High temperature experiments were preformed under the static load of 50 or 70% of the destructive force ensuring constant value of bending moment in the central part of the heated beam. Beams with 2 reinforcement ratios – 0.44 and 1.13% were examined. In total four series of beams, three in each series (12 elements) were used. This paper analyses the reduction of relative beam cross section stiffness depending on reinforcement temperature. Experimentally obtained stiffness values calculated in two ways (element maximal deflection and deflection measured in three points of analysed element) were compared to calculation results made according to Eurocode. The performed analysis shows that reduction of the stiffness of element based on Eurocode calculations is slightly bigger than the experimentally obtained one.

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