Stirrup distribution across the beam width in tension lap splices

1999 ◽  
Vol 26 (1) ◽  
pp. 83-95 ◽  
Author(s):  
K Pacholka ◽  
T Rezansoff ◽  
B F Sparling
Keyword(s):  
Static Loading ◽  
Beam Width ◽  
Static Fatigue ◽  
Test Results ◽  
Slight Improvement ◽  
Fatigue Load ◽  
Lap Splices ◽  
Lap Splice ◽  
Load Cycling ◽  
Transverse Steel

The influence of the distribution of transverse confining steel on the strength of tension lap splices was investigated experimentally in this study. Beam specimens contained three lap-spliced No. 35 bars placed in one layer. Either two or three stirrup legs were placed across the beam width to provide splitting confinement. Both configurations were designed to provide similar stirrup resistances for intercepting horizontal bond splitting. The effectiveness of the different stirrup configurations was compared by investigating the performance of beams subjected to static, fatigue, and fully reversed inelastic loading. Twenty-three full-size beam specimens were tested with the lap splice placed symmetrically within a maximum moment, zero-shear region. Specimens were constructed and tested in six different series (concrete batches). Within each series, the total bond resistance, as evaluated on the basis of CSA A23.3-94, was similar even though the lateral distribution of transverse steel was varied. Nine specimens were tested under monotonically increasing (static) loading to failure, six specimens were subjected to fatigue load cycling between 25% and 75% of their ultimate static strength, and eight specimens were subjected to fully reversed inelastic load cycling. Test results for six similar specimens from a previous study were also included in the current investigation analysis. Test results indicated that using three vertical stirrup legs across the beam width to provide a more uniform distribution of stirrup confinement significantly enhances post yield ductility under fully reversed inelastic load cycling. Meanwhile, specimens tested under static loading showed that CSA A23.3-94 provisions provide a consistent and conservative prediction of lap-splice strength for the specimen configurations investigated, regardless of the distribution of stirrup confinement across the beam width. Finally, the performance of fatigue specimens indicated a slight improvement with the use of the three-leg stirrup configuration. However, this result does not agree with previous observations made at the same institution where it was suggested that stirrup confinement intercepting vertical splitting plays a more significant role in defining fatigue resistance.Key words: reinforced concrete, bond, confinement, lap splices, stirrups, static loading, fatigue load cycling, inelastic load reversal.

Confinement limits for tension lap slices under static loading

1992 ◽  
Vol 19 (3) ◽  
pp. 447-453 ◽  
Author(s):  
T. Rezansoff ◽  
U. S. Konkankar ◽  
Y. C. Fu
Keyword(s):  
Static Loading ◽  
American Concrete Institute ◽  
Concrete Cover ◽  
Transverse Reinforcement ◽  
Lap Splices ◽  
Lap Splice ◽  
Current Limit ◽  
Concrete Confinement ◽  
Bar Diameter ◽  
Concrete Reinforcement

In tension lap splices, the benefit provided to the lap by stirrups placed to intercept longitudinal cracking due to bond splitting action is recognized by the American Concrete Institute code (ACI 318-89) and the design recommendations of ACI Committee 408, on which the American code provisions are partially based. However, a limit exists on the benefit that can be derived from this confinement. In Canada, Canadian Standards Association Standard CAN3 A23.3 M-84 does not directly recognize the confinement benefit provided by stirrups placed along a lap splice. The current study shows that the ACI limit of 1 bar diameter of equivalent concrete cover provided by the transverse reinforcement confinement is too restrictive under static loading. When the concrete cover is small, much larger transverse reinforcement confinement, up to 2-2.5 bar diameters of equivalent concrete cover, can be utilized, in lieu of requiring very long lap lengths. The tests also show that total confinement (actual concrete confinement plus equivalent concrete confinement provided by stirrups) is effective beyond the current limit of 3 main bar diameters, when stirrups are provided. Good performance was found with confinements of 4-4.5 bar diameters, and correspondingly shorter lap splice lengths. Key words: concrete, reinforcement, lap splices, beams, confinement, stirrups, tension, static loading.

scholarly journals Local Behavior of Lap-Spliced Deformed Rebars in Reinforced Concrete Beams

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7186
Author(s):  
Agha Syed Muhammad Gillani ◽  
Seung-Geon Lee ◽  
Soo-Hyung Lee ◽  
Hyerin Lee ◽  
Kee-Jeung Hong
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
American Concrete Institute ◽  
Reinforced Concrete Beams ◽  
Local Behavior ◽  
Test Results ◽  
Loading Test ◽  
Lap Splices ◽  
Lap Splice ◽  
Ductile Behavior

Twelve full-scale reinforced concrete beams with two tension lap splices were constructed and tested under a four-point loading test. Half of these beams had shorter lap splices than that recommended by American Concrete Institute Building Code ACI 318-19; they failed by bond loss between steel and concrete at the lap splice region before rebar yielding. The other half of the beams were designed with a lap splice length slightly exceeding that recommended by ACI 318-19; they failed by rebar yielding and exhibited a ductile behavior. Several strain gauges were attached to the longitudinal bars in the lap splice region to study the local behavior of deformed bars during loading. The strain in a rebar was maximum at the loaded end of the lap splice and progressively decreased toward the unloaded end because the rebar at this end could not sustain any load. Stress flow discontinuity occurred at the loaded end and caused stress concentration. The effect of this concentration was investigated based on test results. The comparison of bond strengths calculated by existing equations and those of tested specimens indicated that the results agreed well.

scholarly journals High cycle (fatigue) resistance of reinforced concrete beams with lap splices

1993 ◽  
Vol 20 (4) ◽  
pp. 642-649 ◽  
Author(s):  
Telvin Rezansoff ◽  
James A. Zacaruk ◽  
Jeffrey G. Afseth
Keyword(s):  
Static Loading ◽  
Fatigue Loading ◽  
Reinforced Concrete Beams ◽  
Bond Failure ◽  
Lap Splices ◽  
Lap Splice ◽  
Major Variable ◽  
Effective Depth ◽  
High Degree ◽  
Tension Loading

Full-scale specimens were tested so that lap spliced bottom bars were subjected to cyclic tension loading. The major variable was the degree of transverse confining reinforcement (stirrups) provided along the lap. Lap splices were confined either with the maximum transverse reinforcement deemed to be effective for static loading, permitting the use of shorter lap splice lengths, or with stirrups spaced at approximately one half the effective depth of the beam, requiring the use of a longer lap length. Failure in all specimens with heavier stirrups (shorter laps) occurred with fatiguing of the reinforcing steel, showing fatigue resistances that were comparable with the results for continuous bars tested in flexure. With the lighter (nominal) stirrups, fatigue loading usually produced a splice failure, where the confining concrete split away from the lap in a typical bond failure after fewer load cycles. For comparable bond resistance under static loading, the beams with the heavier stirrup confinement along a shorter lap length were superior under fatigue loading. As previously shown with low cycle, high intensity reversal (seismic) loading, the current study shows that it is prudent to provide a high degree of transverse reinforcing confinement to lap splices that are subjected to fatigue loading. Key words: concrete, reinforcement, lap splices, fatigue, bond, beams, confinement, stirrups, tension.

Correlation of the bond provisions of CSA A23.3-94 with tests on tension lap splices in beams

1995 ◽  
Vol 22 (4) ◽  
pp. 755-769 ◽  
Author(s):  
T. Rezansoff ◽  
B. F. Sparling
Keyword(s):  
Static Loading ◽  
Factor Of Safety ◽  
Accurate Estimate ◽  
Development Length ◽  
Structural Bond ◽  
Lap Splices ◽  
Lap Splice ◽  
Wide Range ◽  
Modification Factor ◽  
Definition Of

Data on beams with tension lap splices tested under static loading at the same institution over the past two decades are correlated with the bond provisions of the Canadian concrete standard CAN/CSA A23.3-94 (detailed design approach), as well as with the recommendations of ACI Committee 408, on which the Canadian standard appears to be largely based. The correlations show that transverse reinforcement is more effective than the new bond provisions allowed in cases where the bond failure is governed by splitting rather than bar pullout. Extending the effective limits for confinement provides a more accurate estimate of the bond resistance available at higher levels of confinement, resulting in a more uniform factor of safety over a wide range of confinements. Lap splices with no transverse confinement showed relatively poorer performance than lap splices with varying degrees of transverse confinement when correlated with resistances predicted on the basis of the new CAN/CSA A23.3-94 provisions. Weaker relative splice performance in the absence of transverse confinement raises a concern for the development lengths required by the CAN/CSA A23.3-94 provisions. With highly stressed lap splices, a class factor of 1.3 is applied to the basic development length to determine the lap length. Published information, on the other hand, has shown that lap splice lengths and development lengths should be the same for transferring or developing the same level of stress in tension reinforcement when the same level of confinement is provided along the anchorage. In contrast, the ACI Committee 408 recommendations use a larger factor of safety on development length and lap splice length, rather than applying class factors for splices only, making splice and development lengths the same for the same confinement and required strength transfer. For the data considered, required lap lengths are similar using both the CSA Standard CAN/CSA A23.3-94 (including the 1.3 class factor) and the ACI 408 recommendations, and only small differences in overall prediction accuracy were found. Differences in the definition of the concrete confinement term for close bar spacing by the two design models, different limits on the total confinement that can be considered effective, as well as a further modification factor for bar size in the CAN/CSA A23.3-94 provisions, result in only small differences in lap length requirements for most of the data considered. Key words: anchorage (structural), bond, confinement, lap splices, reinforced concrete, standards, static loading, tension.

scholarly journals Test and Numerical Model of Curved Steel–Concrete Composite Box Beams under Positive Moments

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2978
Author(s):  
Zhi-Min Liu ◽  
Xue-Jin Huo ◽  
Guang-Ming Wang ◽  
Wen-Yu Ji
Keyword(s):  
Finite Element ◽  
Static Loading ◽  
Composite Beams ◽  
Parameter Analysis ◽  
Outer Side ◽  
Finite Element Models ◽  
Test Results ◽  
Rotational Angle ◽  
Shear Connection ◽  
Box Beams

Compared with straight steel–concrete composite beams, curved composite beams exhibit more complicated mechanical behaviors under combined bending and torsion coupling. There are much fewer experimental studies on curved composite beams than those of straight composite beams. This study aimed to investigate the combined bending and torsion behavior of curved composite beams. This paper presents static loading tests of the full elastoplastic process of three curved composite box beams with various central angles and shear connection degrees. The test results showed that the specimens exhibited notable bending and torsion coupling force characteristics under static loading. The curvature and interface shear connection degree significantly affected the force behavior of the curved composite box beams. The specimens with weak shear connection degrees showed obvious interfacial longitudinal slip and transverse slip. Constraint distortion and torsion behavior caused the strain of the inner side of the structure to be higher than the strain of the outer side. The strain of the steel beam webs was approximately linear. In addition, fine finite element models of three curved composite box beams were established. The correctness and applicability of the finite element models were verified by comparing the test results and numerical calculation results for the load–displacement curve, load–rotational angle curve, load–interface slip curve, and cross-sectional strain distribution. Finite element modeling can be used as a reliable numerical tool for the large-scale parameter analysis of the elastic–plastic mechanical behavior of curved composite box beams.

Design, Testing, and Simulation of Fibre Composite Leaf Springs For Heavy Axle Loads

2005 ◽  
Vol 40 (6) ◽  
pp. 497-504 ◽  
Author(s):  
J P Hou ◽  
J-Y Cherruault ◽  
G Jeronimidis ◽  
R Mayer
Keyword(s):  
Static Loading ◽  
Fibre Composite ◽  
Bending Stress ◽  
Test Results ◽  
Element Analysis ◽  
Leaf Springs ◽  
Manufacturing Testing ◽  
Drop Tests ◽  
Glass Fibre Reinforced ◽  
Load Conditions

This paper summarizes the design, manufacturing, testing, and finite element analysis (FEA) of glass-fibre-reinforced polyester leaf springs for rail freight vehicles. FEA predictions of load-deflection curves under static loading are presented, together with comparisons with test results. Bending stress distribution at typical load conditions is plotted for the springs. The springs have been mounted on a real wagon and drop tests at tare and full load have been carried out on a purpose-built shaker rig. The transient response of the springs from tests and FEA is presented and discussed.

scholarly journals Uniaxial Cyclic Tests on Reinforced Concrete Members with Lap Splices

2019 ◽  
Vol 35 (2) ◽  
pp. 1023-1043 ◽  
Author(s):  
Danilo Tarquini ◽  
João P. Almeida ◽  
Katrin Beyer
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Local Deformation ◽  
Experimental Program ◽  
Loading History ◽  
Cyclic Tests ◽  
Continuous Reinforcement ◽  
Lap Splices ◽  
Lap Splice ◽  
Concrete Members

This data paper presents the quasi-static uniaxial cyclic tests of 24 reinforced concrete members, of which 22 feature lap splices and 2 are reference units with continuous reinforcement. The objective of the experimental program is to investigate the influence of lap splice length ( ls), confining reinforcement, and loading history on the behavior of lap splices. Particular attention is placed on the measurement of local deformation quantities, such as lap splice strains and rebar-concrete slip. Details of the geometry and reinforcement layout of the specimens as well as the employed test setup, instrumentation, and loading protocols are provided. The global behavior of the test units, including the observed crack pattern and failure modes, are discussed. The organization of the experimental data, which are made available for public use under DOI: 10.5281/zenodo.1205887, is outlined in detail.

Measurement of Residual Stress in Water Pipe Welds Using the Hole-Drilling Technique

2007 ◽  
Vol 353-358 ◽  
pp. 2419-2422
Author(s):  
Jung Hun Choi ◽  
Jong Hyun Baek ◽  
Dae Jin Kim ◽  
Jae Mean Koo ◽  
Chang Sung Seok
Keyword(s):  
Residual Stress ◽  
Size Effect ◽  
Standard Specimen ◽  
Weld Zone ◽  
Hole Drilling ◽  
Test Results ◽  
Water Pipe ◽  
Fatigue Load ◽  
Drilling Technique ◽  
Fatigue Characteristics

In case of large steel water pipe, it have been observed that its fracture mostly occurs due to the complicated outside fatigue load on the pipe in the underground. It is also well known that its damage and leakage happen mainly in a weld zone. In this study we evaluated the fatigue characteristics based on size effect and residual stress by comparing the test results on the standard specimen collected from real pipe with those on full scale pipe.

scholarly journals Static and Fatigue Failures of Adhesively Bonded Laminate Joints in Moist Environments

2011 ◽  
Vol 20 (8) ◽  
pp. 1217-1242 ◽  
Author(s):  
K. B. Katnam ◽  
A. D. Crocombe ◽  
H. Sugiman ◽  
H. Khoramishad ◽  
I. A. Ashcroft
Keyword(s):  
Cohesive Zone ◽  
Experimental Tests ◽  
Static Fatigue ◽  
Test Results ◽  
Adhesively Bonded ◽  
Aerospace Applications ◽  
Numerical Predictions ◽  
Fatigue Failures ◽  
Good Agreement

Advanced structural adhesives are now an important joining technique in automobile and aerospace applications. The perceived uncertainty in the long-term structural performance of bonded members when subjected to static/fatigue loads in aggressive environments is probably restricting an even more widespread use of this joining technology. In this article, the effect of moisture on the static and fatigue resistances of adhesively bonded laminate joints was investigated. Experimental tests were performed on both aged and unaged adhesively bonded laminate joints for static and fatigue responses. Further, using a cohesive zone approach for the adhesive bondlines, a combined diffusion–stress analysis was developed to predict the progressive damage observed in the joints tested experimentally. The numerical predictions were found to be in good agreement with the experimental test results.

Improvement of Fatigue Strength and Impact Properties of Plain-Woven CFRP Modified with Micro Fibrillated Cellulose

2008 ◽  
Vol 47-50 ◽  
pp. 133-136 ◽  
Author(s):  
Norifumi Takagaki ◽  
Kazuya Okubo ◽  
Toru Fujii
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Carbon Fiber ◽  
Impact Load ◽  
Static Fatigue ◽  
Test Results ◽  
Static Properties ◽  
Impact Properties ◽  
Matrix Cracks ◽  
The Matrix

This study investigated the effect of the enhancement by addition of Micro Fibrillated Cellulose (MFC) on the static, fatigue and impact properties of plain-woven CFRP. Test results showed that the addition of MFC little contributed to the improvement of static properties. However, the initiation of matrix cracks between woven carbon fiber cloths was prevented under cyclic loading so that the fatigue life of the CFRP was improved by the modification with MFC. The ductility of plain-woven CFRP was also acquired under impact load by the addition of the MFC to the matrix.

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