Behaviour of adhesive steel anchors under impulse-type loading

2009 ◽  
Vol 36 (11) ◽  
pp. 1835-1847 ◽  
Author(s):  
Abass Braimah ◽  
Ettore Contestabile ◽  
Rick Guilbeault
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Dynamic Behaviour ◽  
Stone Masonry ◽  
Experimental Program ◽  
Embedment Depth ◽  
Test Results ◽  
Dynamic Increase Factor ◽  
Adhesive Anchors

The dynamic behaviour of adhesive anchors embedded in concrete is not well established, neither is their behaviour in stone masonry. This paper presents an experimental program designed to study the dynamic behaviour of adhesive anchor – substrate systems under impulse-type loading. The adhesive anchor – substrate systems consisted of steel rods bonded to concrete and limestone with an epoxy-based adhesive. Two steel anchor diameters (6.4 and 9.5 mm), two embedment depths (89 and 114 mm), and two angles of substrate penetration (90° and 45°) were investigated. The predominant failure mode observed for the steel anchor – concrete substrate samples was steel fracture, whereas for the steel anchor – limestone substrate samples, both steel fracture and limestone substrate failure modes were observed. The test results show that in most cases the dynamic increase factor (DIF) of adhesive anchors decreases with an increase in the embedment depth. Also, a substrate penetration angle of 45° increases the DIF in comparison with samples with 90° penetration angle. The DIFs of 1.2 and 2.5 are recommended for adhesive anchors with normal and 45° limestone substrate penetrations, respectively, while for concrete substrate, the recommended DIFs are 1.2 and 3.2 for normal and 45° substrate penetrations, respectively.

Pull-Out Behavior of Adhesive Connections in Unreinforced Masonry Walls

2016 ◽  
Vol 32 (4) ◽  
pp. 2357-2375 ◽  
Author(s):  
Dmytro Dizhur ◽  
Arturo Schultz ◽  
Jason Ingham
Keyword(s):  
Failure Modes ◽  
Unreinforced Masonry ◽  
Experimental Program ◽  
Masonry Walls ◽  
Embedment Depth ◽  
Clay Brick ◽  
Metal Mesh ◽  
Comparative Performance ◽  
Pull Out ◽  
Adhesive Anchors

The connections between walls of unreinforced masonry (URM) buildings and flexible timber diaphragms are critical building components that must perform adequately before desirable earthquake response of URM buildings may be achieved. Field observations made during the initial reconnaissance and the subsequent damage surveys of clay brick URM buildings following the 2010/2011 Canterbury, New Zealand, earthquakes revealed numerous cases where anchor connections joining masonry walls or parapets with roof or floor diaphragms appeared to have failed prematurely. These observations were more frequent for adhesive anchor connections than for through-bolt connections (i.e., anchorages having plates on the exterior facade of the masonry walls). Subsequently, an in-field test program was undertaken in an attempt to evaluate the performance of adhesive anchor connections between unreinforced clay brick URM walls and roof or floor diaphragm. The study consisted of a total of almost 400 anchor tests conducted in eleven existing URM buildings located in Christchurch, Whanganui and Auckland. Specific objectives of the study included the identification of failure modes of adhesive anchors in existing URM walls and the influence of the following variables on anchor load-displacement response: adhesive type, strength of the masonry materials (brick and mortar), anchor embedment depth, anchor rod diameter, overburden level, anchor rod type, quality of installation, and the use of metal mesh sleeves. In addition, the comparative performance of bent anchors (installed at an angle of minimum 22.5° to the perpendicular projection from the wall surface) and anchors positioned horizontally was investigated. Observations on the performance of wall-to-diaphragm connections in the 2010/2011 Canterbury earthquakes, a summary of the performed experimental program and test results, and a proposed pull-out capacity relationship for adhesive anchors installed into multi-leaf clay brick masonry are presented herein.

scholarly journals Numerical and Experimental Investigation on Concrete Splitting Failure of Anchor Channels

CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 502-522
Author(s):  
Anton Bogdanić ◽  
Daniele Casucci ◽  
Joško Ožbolt
Keyword(s):  
Construction Industry ◽  
Failure Mode ◽  
Current Trend ◽  
The United States ◽  
Embedment Depth ◽  
Test Results ◽  
Concrete Members ◽  
Splitting Failure ◽  
Edge Distance ◽  
Numerical Parametric Study

Concrete splitting failure due to tension load can occur when fastening systems are located close to an edge or corner of a concrete member, especially in thin members. This failure mode has not been extensively investigated for anchor channels. Given the current trend in the construction industry towards more slender concrete members, this failure mode will become more and more relevant. In addition, significantly different design rules in the United States and Europe indicate the need for harmonization between codes. Therefore, an extensive numerical parametric study was carried out to evaluate the influence of member thickness, edge distance, and anchor spacing on the capacity of anchor channels in uncracked and unreinforced concrete members. One of the main findings was that the characteristic edge distance depends on the member thickness and can be larger than 3hef (hef = embedment depth) for thin members. Based on the numerical and experimental test results, modifications of the design recommendations for the splitting failure mode are proposed. Overall, the authors recommend performing the splitting verification separately from the concrete breakout to design anchor channels in thin members more accurately.

Assesment of Main Models for Predicting Debonding Load-Bearing Capacity against Intermediate Crack-Induced Debonding Failure in FRP-Strengthened RC Beams

2011 ◽  
Vol 311-313 ◽  
pp. 1941-1944
Author(s):  
Gui Bing Li ◽  
Yu Gang Guo ◽  
Xiao Yan Sun
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Failure Modes ◽  
Rc Beams ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Accuracy Test ◽  
New Models ◽  
Debonding Load

intermediate crack-induced debondingis one of the most dominant failure modes in FRP-strengthened RC beams. Different code models and provisions have been proposed to mitigateintermediate crack-induced debondingfailure.However, these models and provisions can not mitigate this failure mode effectively. Recnetly, new models have been proposed to solve this problem. Out of all the existing models, four typical ones are investigated in the current study. A comprehensivecomparison among these models is carried out in order to evaluate their performance and accuracy. Test results offlexural specimens with intermediate crack-induced debonding failurecollected from the existing literature are used in the current comparison. The effectivenessand accuracy of each model have been evaluated based on these experimental results. It is shown that the current modals are all conservative and inadequite to effectively mitigate intermediate crack-induced debonding in flexurally strengthened members.

PULL OUT STRENGTH FOR DIFFERENT SIZE OF DOWEL AND GRAIN DIRECTION OF GLULAM

2016 ◽  
Vol 78 (5-4) ◽  
Author(s):  
Tengku Anita Raja Hussin ◽  
Mohamad Iswandi Jinne ◽  
Rohana Hassan
Keyword(s):  
Failure Modes ◽  
Maximum Load ◽  
Experimental Program ◽  
Drilling Process ◽  
Test Results ◽  
Bond Behaviour ◽  
Pull Out ◽  
Timber Joints ◽  
Different Thickness ◽  
Pull Out Strength

This paper presents an experimental program for testing glued-in dowel glulam timber joints. Hundred thirty glulam specimens, each with a single glued-in rebar parallel to the grain and perpendicular to grain with different size of dowels 12mm, 16mm and 20mm were tested to evaluate the effects of anchorage length and different dowel diameter for parallel and perpendicular to the grain on pull-out strength and bond behaviour of glued-in rebar timber joints. The test results showed that the maximum load for specimen with dowel glued-in parallel to the grain given the higher maximum load than dowel glued-in perpendicular to the grain direction. Failure modes were characterized by pull out failure in the mode of adhesive-dowel, yet one sample failed in timber-adhesive mode. This might happened because the surface of the timber was burned by drilling machine during the drilling process. The pull-out was tested with different thickness grain direction with different dowel size with a rate of 2mm/min and the failure modes were observed after the testing of pull-out test. PRF is the adhesive used for the strengthening purposes. Resistance to the withdrawal of dowels glued-in perpendicularly was 44.2% to 53.5 % lower than that obtained for dowels glued-in parallel to the grain direction. The result shows that the dowel glued-in parallel to the grain given the higher maximum load than dowel glued-in perpendicular to the grain direction.

scholarly journals Behavior of wood beam connection using staples subjected to in-plane moment

2019 ◽  
Vol 258 ◽  
pp. 05008
Author(s):  
Farida Lenggani ◽  
Bambang Suryoatmono
Keyword(s):  
Failure Mode ◽  
Failure Modes ◽  
Solid Wood ◽  
Experimental Results ◽  
Elastic Analysis ◽  
Connection Strength ◽  
Test Results ◽  
Lateral Resistance ◽  
Wood Beams ◽  
Mechanical Fasteners

It is very frequent that solid wood beams need to be connected one to another to obtain a longer beam. In this study, the behavior of solid wood beams connections using plywood sheets as connecting elements and staples as mechanical fasteners were studied experimentally. The experimental results were compared with elastic analyses. Both beam and plywood were made of meranti (shorea). The staple type was MAX 1022J. This study was conducted on two specimens. The first specimen had two rows of staples on the front and back sides of the specimen. Each row consisted of ten staples making a total of 40 staples. The second one had three rows of staples on the front and back sides of the specimen. Each row consisted of ten staples making a total of 60 staples. From the tests, it can be concluded that each material in the connection, namely wood beam, plywood, and staples, failed. Failure mode of the wood beam was in the form of crack and tear. Failure mode of the plywood was the damage of the plywood directly contacted with the crown of the staples. Failure modes of the staples were flexural yielding. The differences between connection strength obtained from tests and elastic analyses were 8.18% for the first specimen and 0.65% for the second specimen, with the test results were higher than the elastic analyses results. It can be concluded that elastic analysis is quite accurate and conservative to estimate the strength of this type of connection, provided that the lateral resistance of connection with a staple is known.

On the Dynamic Behaviour of Strengthened Stone Masonry Walls

2010 ◽  
Vol 133-134 ◽  
pp. 671-676
Author(s):  
Abdelsamie Elmenshawi ◽  
Mohamed Sorour ◽  
Don Duchesne ◽  
Jocelyn Paquette ◽  
Aftab Mufti ◽  
...  
Keyword(s):  
Cultural Values ◽  
Stone Masonry ◽  
Experimental Program ◽  
Masonry Building ◽  
Test Results ◽  
Shake Table Tests ◽  
Seismic Codes ◽  
Historic Structures ◽  
Out Of Plane ◽  
Stone Walls

Unreinforced stone masonry is common in heritage structures worldwide. Unfortunately, these structures are susceptible to failure or severe damage when subject to dynamic or seismic loading. Conservation of historic structures is a challenge as the heritage and cultural values need to be preserved while the advent of new seismic codes may require major strengthening to be implemented. The new seismic codes demand high seismic strength and ductility for such structures, whereas neither the strength nor the ductility of an existing stone masonry building can be quantified easily. The Parliament buildings of Canada fall into this category. Therefore, an extensive experimental program was carried out to investigate the dynamic and seismic behaviours of stone walls representative of Canada’s Parliament buildings. The walls were constructed of double stone wythes with the cavity between being filled with weak mortar, shards and small stones, constituting a rubble core of the walls. The experimental program included in-plane quasi-static, free vibration and high frequency loadings, together with out-of-plane shake table tests. The tests were aimed at investigating the integrity, strength, damping, stiffness degradation, and ductility of the walls. Different potential strengthening methods were assessed, methods that would minimize structural intervention and preserve the heritage values of the building. The methods involved different metallic anchors and traditional stone interlocking to tie the two outer wythes together. Fortunately, the stone walls exhibited satisfactory performance in all cases. In addition, the test results suggested that plain un-strengthened stone walls had strength and other characteristics similar to those of the rehabilitated walls, in the range of the imposed load scenarios.

A Performance Study on Self-Piercing Riveting and Adhesive Hybrid Joints of Different Adhesive

2014 ◽  
Vol 887-888 ◽  
pp. 1261-1264
Author(s):  
Fu Long Liu ◽  
Xiao Cong He ◽  
Yu Qi Wang
Keyword(s):  
Failure Mechanism ◽  
Energy Absorption ◽  
Failure Mode ◽  
Failure Modes ◽  
Test Results ◽  
Performance Study ◽  
Strength Capacity ◽  
Hybrid Joints ◽  
Overall Performance ◽  
Tension Loading

This paper studied the performance of self-piercing riveting (SPR) and adhesive hybrid joints of different adhesive, including strength, capacity of energy absorption, failure mode and failure mechanism of the hybrid joints. The performances of SPR-adhesive hybrid joints were compared with SPR joints. SPR-adhesive hybrid joints and SPR joints were tested under a tension loading. The test results showed that adhesive have a function of improving the strength of SPR joints; however, the capacity of energy absorption of SPR joints was weakened. While the adhesive have no effect on the failure modes of SPR joints. When appropriate adhesive was selected, the overall performance of SPR-adhesive hybrid joints was superior to SPR joints. In a word, the combination of SPR and adhesive could get a well jointing structure.

Tests on Strength of Coped Beams with Web Stiffening

2010 ◽  
Vol 163-167 ◽  
pp. 605-609
Author(s):  
Michael C H Yam ◽  
Hong Wei Ma ◽  
Kwok Fai Chung
Keyword(s):  
Failure Mode ◽  
Body Movement ◽  
Experimental Program ◽  
Test Results ◽  
Depth Ratio ◽  
Beam Depth ◽  
Test Parameters ◽  
Longitudinal Stiffeners ◽  
Final Failure ◽  
Web Buckling

In steel construction, when beams have to be connected to a girder at the same elevation, beam flanges must often be coped to provide enough clearance for practical joint formation. The presence of a cope in a beam will reduce the strength of the beam in the coped region. To improve the strength of coped beams, web reinforcements at the coped region were proposed in previous research studies. This paper reports the results of the first phase of the experimental program. A total of 8 tests were conducted. The test parameters include the length of longitudinal stiffeners, cope depth to beam depth ratio, cope length to beam depth ratio, and doubler plate. The test results show that the strength of the coped beam specimens was significantly increased when stiffeners were used in the cope. The increase in strength due to the presence of the longitudinal stiffeners could be as high as 96%. The longitudinal stiffeners were able to prevent local web buckling from occurring at the cope, however, the final failure mode of the beams was yielding of non-reduced section followed by rigid body movement of stiffener. The doubler plate was able to increase the strength of the beams; however, the final failure mode of the beams was still local web buckling.

Failure Modes and Acceptance Criteria of Reinforced Prestressed Concrete Railway Sleepers Based on Dynamic Loading Tests

2015 ◽  
Vol 752-753 ◽  
pp. 522-527 ◽  
Author(s):  
Marcela Karmazínová
Keyword(s):  
Dynamic Loading ◽  
Prestressed Concrete ◽  
Crack Width ◽  
Failure Modes ◽  
Dynamic Behaviour ◽  
Test Results ◽  
Acceptance Criteria ◽  
Loading Tests ◽  
The Moment ◽  
Total Fracture

The paper is focused on the problems of the dynamic behaviour, failure and resistance of reinforced prestressed concrete railway sleepers, developed and verified continuously in the period of several last years. The results of dynamic loading tests are presented for the sleepers for both wide and narrow track gauge. The test results have been evaluated using the criteria for the acceptance based on the load corresponding to the prescribed crack width and the load at the moment of total fracture.

Influence of Rubber Content on Failure Mode and Resistance Characteristics of PC/ABS Blends and their ABS Constituents under Impact

2021 ◽  
Vol 892 ◽  
pp. 67-73
Author(s):  
Muhammad Nizar Machmud ◽  
Masaki Omiya ◽  
Hirotsugu Inoue ◽  
Kikuo Kishimoto
Keyword(s):  
Impact Toughness ◽  
Impact Strength ◽  
Failure Mode ◽  
Room Temperature ◽  
Failure Modes ◽  
Impact Test ◽  
Rubber Particle ◽  
Test Results ◽  
Rubber Content ◽  
Particle Content

This present study has been re-established to investigate failure mode and resistance characteristics of the PC/ABS blends and their ABS constituents under impact for a range of rubber contents. This present study has still been experimentally performed under an instrumented-drop weight impact test (DWIT) at a room temperature. It has been finally revealed that with a particular size of rubber particle, content of rubber significantly influenced impact failure modes and impact resistances of the PC/ABS blends and their ABS constituents as well. The test results showed that impact strength of the blends was improved about 23.22% and 155.33% due to increase in content of rubber up to 15 wt% and 20 wt%, respectively. There was also found that an increase in impact toughness of the blends for 57.48% and 239.23% was due to increase in content of rubber up to 15 wt% and 20 wt%, respectively. Whilst, impact strength of the ABS was improved about 392.98% and 190.12% due to increase in content of rubber up to 15 wt% and 20 wt%, respectively. An increase in impact toughness of the ABS for 308.20% and 172.56% was due to increase in content of rubber up to 15 wt% and 20 wt%, respectively.

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