Longitudinal cracking of composite beams with ribbed metal deck

1986 ◽  
Vol 13 (6) ◽  
pp. 733-740 ◽  
Author(s):  
M. S. Elkelish ◽  
Hugh Robinson
Keyword(s):  
Analytical Study ◽  
Concrete Slab ◽  
Single Point ◽  
Longitudinal Crack ◽  
Composite Beams ◽  
Point Load ◽  
Width Ratio ◽  
Slab Width ◽  
Longitudinal Cracking ◽  
Solid Part

An analytical study of the longitudinal cracking of composite beams with ribbed concrete slab on metal deck is presented. A layered finite element is used to model the composite beam in the analysis. The influence of six parameters on the development of the longitudinal crack is investigated in this study. These parameters are type of loading, compressive strength of the concrete slab, beam span to slab width ratio, thickness of the solid part of the slab, percentage of transverse reinforcement, and the existence of the metal deck. Three types of loading are considered, namely, uniformly distributed load over the entire slab area, single point load applied at mid-span of the beam, and two point loads applied at the third points of the span. The type of loading of composite beams has a significant effect on the location of the initial longitudinal crack.

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.

Analyses and tests to determine the effective widths of composite beams in unbraced multistorey frames

1986 ◽  
Vol 13 (1) ◽  
pp. 66-75 ◽  
Author(s):  
E. H. Fahmy ◽  
Hugh Robinson
Keyword(s):  
Concrete Slab ◽  
Concrete Strength ◽  
Composite Beams ◽  
Steel Frame ◽  
Slab Width ◽  
Lateral Forces ◽  
Measured Strain ◽  
Ultimate Moment ◽  
Strength And Stiffness ◽  
Good Agreement

This paper concerns the analysis and testing of 10 cantilever composite beams incorporating ribbed metal deck, representing the positive moment beam–column connections in an unbraced steel frame with composite floor beams. The positive moment beam–column connections arise from lateral forces on the unbraced frame. The effective widths of the slabs for strength and stiffness calculations have been determined from analysis. Agreement between the calculated strain distributions across the concrete slab width and the corresponding measured strain distributions was attained. Use of the calculated effective widths of the slab for strength together with a concrete strength of [Formula: see text] gave good agreement with the measured positive ultimate moment capacities of the cantilever composite beams subjected to upward end test loads.

scholarly journals Effective Flange Width for Composite Steel Beams

2011 ◽  
Vol 7 (2) ◽  
pp. 28 ◽  
Author(s):  
T. Salama ◽  
H.H. Nassif
Keyword(s):  
Concrete Slab ◽  
Composite Beams ◽  
Analytical Investigation ◽  
Steel Beams ◽  
Limit States ◽  
Composite Action ◽  
Shear Connectors ◽  
Slab Width ◽  
Effective Flange Width ◽  
Composite Steel

 The effective flange width is a concept proposed by various codes to simplify the computation of stress distribution across the width of composite beams. Questions have been raised as to the validity of the effective slab width provisions, since they have a direct effect on the computed ultimate moment as well as serviceability limit states such as deflection, fatigue, and overloading. The objective of this paper is to present results from an experimental and analytical investigation to determine the effective slab width in steel composite beams. The Finite Element Method (FEM) was employed for the analysis of composite steel-concrete beams having variable concrete flange widths. Results were compared to those from tests performed on eight beams loaded to failure. Beam test specimens had variable flange width and various degrees of composite action (shear connectors). The comparison presented in terms of the applied load versus deflection, and strain in the concrete slab show that the AISC-LRFD code is conservative and underestimates the width active. Based on a detailed parametric study an equation for the calculation of the effective flange width is recommended. 

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.

Ultimate Bearing Capacity of Steel-Reactive Powder Concrete Composite Beams

2014 ◽  
Vol 900 ◽  
pp. 473-482 ◽  
Author(s):  
Li Zhong Han ◽  
Jin Quan Zhang ◽  
Jian Guo Nie
Keyword(s):  
Bearing Capacity ◽  
Concrete Slab ◽  
Composite Beams ◽  
Ultimate Bearing Capacity ◽  
Reactive Powder Concrete ◽  
Width Ratio ◽  
Critical Crack ◽  
Negative Moment ◽  
Reactive Powder ◽  
Tension Strength

Concrete slab in the negative moment area of continuous steel-concrete composite beams is prone to crack due to the low tension strength of common concrete, which could result in the decreasing of the strength and durability. To solve this problem, a method of replacing the concrete slab with reactive powder concrete (RPC) slab which is of super high strength, durability, toughness and volume stabilization is presented. According to the constitutive relation and the high tension strength of RPC, the normal section failure mode is defined as the critical crack state, and the calculation formula of ultimate bearing capacity is deduced. Finally, some parameters that influence the ultimate bearing capacity are analyzed, such as the height ratio of RPC slab to whole beam, width ratio of RPC slab to steel beam, and the ratio of reinforcement of RPC slab. Compared with the steel-concrete composite beams, it is indicated that in the precondition of RPC slab unallowable crack in negative moment area, the ultimate bearing capacity of steel-RPC composite beams can still be increased, and the crack resistance, stiffness and durability can all be enhanced greatly.

Analysis of Long-Term Stress of Steel-Concrete Composite Beams

2010 ◽  
Vol 163-167 ◽  
pp. 2037-2040
Author(s):  
Min Ding ◽  
Jin San Ju ◽  
Xiu Gen Jiang
Keyword(s):  
Relative Humidity ◽  
Concrete Slab ◽  
Concrete Strength ◽  
Composite Beams ◽  
Reinforcement Ratio ◽  
Longitudinal Reinforcement ◽  
Slab Width ◽  
Yearly Average ◽  
Average Relative Humidity

The theoretical model to compute long-term stress of steel-concrete composite beam was deduced. On this basis, the effects of factors such as concrete age to loading, longitudinal reinforcement ratio in concrete slab, concrete slab width, environmental yearly average relative humidity and concrete strength on long-term stress of composite beams are discussed. The results show that additional stress at the top of concrete slab is tensile stress and that at the bottom of steel beam is compressive stress. Concrete slab width, as well as longitudinal reinforcement ratio can not be ignored. Concrete strength and concrete age to loading have relatively bigger effect as well. But environmental yearly average relative humidity has less impact.

Effective widths of composite beams with ribbed metal deck

1986 ◽  
Vol 13 (5) ◽  
pp. 575-582 ◽  
Author(s):  
S. Elkelish ◽  
Hugh Robinson
Keyword(s):  
Compressive Strength ◽  
Composite Beam ◽  
Ultimate Load ◽  
Concrete Slab ◽  
Composite Beams ◽  
Analytical Investigation ◽  
Steel Beam ◽  
Effective Width ◽  
Slab Width ◽  
Service Load

The effective width of the concrete slab of a composite beam is used in the determination of its moment resistance and service load moment for the purposes of structural design of the composite beam. It is usually assumed that the same effective width of the concrete slab may be used for both ultimate strength and elastic stage calculations.This paper presents the results of an analytical investigation of the variation of the effective width of composite beams and ribbed slabs formed by ribbed metal deck in both the elastic and inelastic stages and at ultimate load. A layered finite element method is used to model the composite beam. The influence of four variables on the effective width of the composite beams was studied, namely, type of loading, beam span to actual concrete slab width, ultimate compressive strength of the concrete, and steel beam size.It was found that the effect of the compressive strength of the concrete and the size of the steel beam have negligible influence on the effective width of the concrete slab. The effective width of the slab at ultimate load is of the order of 4% larger than that in the elastic range.The effective width used for the design of composite beams under a uniformly distributed load, which is the practical loading in most cases, is significantly different from that which should be used for any other type of loading.

The Influence of Slab Concreting Sequence on a Continuous Composite Girder Bridge

2016 ◽  
Vol 691 ◽  
pp. 96-107
Author(s):  
Tomas J. Zivner ◽  
Rudolf B. Aroch ◽  
Michal M. Fabry
Keyword(s):  
Concrete Slab ◽  
Transverse Cross Section ◽  
Slab Thickness ◽  
Slab Width ◽  
Composite Girder ◽  
Steel Members ◽  
Composite Bridge ◽  
Bridge Girder ◽  
Girder Bridge ◽  
Main Girder

This paper deals with the slab concreting sequence and its influence on a composite steel and concrete continuous highway girder bridge. The bridge has a symmetrical composite two-girder structure with three spans of 60 m, 80 m, 60 m (i.e. a total length between abutments of 200.0 m). The horizontal alignment is straight. The top face of the deck is flat. The bridge is straight. The transverse cross-section of the slab is symmetrical with respect to the axis of the bridge. The total slab width is 12 m. The slab thickness varies from 0.4 m on main girders to 0.25 m at its free edges and 0.3075 m at its axis of symmetry. The center-to-center spacing between main girders is 7 m and the slab cantilever on either side is 2.5 m long. Every main girder has a constant depth of 2800 mm and the thicknesses of the upper and lower flanges are variable. The lower flange is 1200 mm wide whereas the upper flange is 1000 mm wide. The two main girders have transverse bracing at abutments and at internal supports and at regular intervals in every span. The material of concrete slab is C35/45 and of steel members S355. The on-site pouring of the concrete slab segments is performed by casting them in a selected order and is done after the launching of the steel two girder bridge. The paper presents several concreting sequences and their influence on the normal stresses and deflections of the composite bridge girder.

Employing Surface Roughness for Bridge-Vehicle Interaction Based Damage Detection

2011 ◽  
Author(s):  
Vesna Jaksic ◽  
Vikram Pakrashi ◽  
Alan O’Connor
Keyword(s):  
Surface Roughness ◽  
Damage Detection ◽  
Flexural Rigidity ◽  
Single Point ◽  
Point Load ◽  
Ride Quality ◽  
Breathing Crack ◽  
Bernoulli Beam ◽  
Statistical Parameters ◽  
Euler Bernoulli Beam

Damage detection and Structural Health Monitoring (SHM) for bridges employing bridge-vehicle interaction has created considerable interest in recent times. In this regard, a significant amount of work is present on the bridge-vehicle interaction models and on damage models. Surface roughness on bridges is typically used for detailing models and analyses are present relating surface roughness to the dynamic amplification of response of the bridge, the vehicle or to the ride quality. This paper presents the potential of using surface roughness for damage detection of bridge structures through bridge-vehicle interaction. The concept is introduced by considering a single point observation of the interaction of an Euler-Bernoulli beam with a breathing crack traversed by a point load. The breathing crack is treated as a nonlinear system with bilinear stiffness characteristics related to the opening and closing of crack. A uniform degradation of flexural rigidity of an Euler-Bernoulli beam traversed by a point load is also considered in this regard. The surface roughness of the beam is essentially a spatial representation of some spectral definition and is treated as a broadband white noise in this paper. The mean removed residuals of beam response are analyzed to estimate damage extent. Uniform velocity and acceleration conditions of the traversing load are investigated for the appropriateness of use. The detection and calibration of damage is investigated through cumulant based statistical parameters computed on stochastic, normalized responses of the damaged beam due to passages of the load. Possibilities of damage detection and calibration under benchmarked and non-benchmarked cases are discussed. Practicalities behind implementing this concept are also considered.

New composite beams having cold-formed steel joists and concrete slab

2014 ◽  
Vol 71 ◽  
pp. 187-200 ◽  
Author(s):  
Cheng-Tzu Thomas Hsu ◽  
Sun Punurai ◽  
Wonsiri Punurai ◽  
Yazdan Majdi
Keyword(s):  
Concrete Slab ◽  
Composite Beams ◽  
Cold Formed Steel
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