INFLUENCE OF RECTANGULAR STEEL SPLICE-SLEEVE FOR PRECAST CONCRETE CONNECTION

2015 ◽  
Vol 77 (12) ◽  
Author(s):  
Ahmad Baharuddin Abd Rahman ◽  
Tan Kee Hong ◽  
Izni Syahrizal Ibrahim ◽  
Roslli Noor Mohamed
Keyword(s):  
Structural Integrity ◽  
Precast Concrete ◽  
Tensile Load ◽  
Steel Plates ◽  
Steel Bar ◽  
Tensile Performance ◽  
Bond Property ◽  
The Many ◽  
Steel Sleeve

Precast concrete building system has gained its popularity in Malaysia because of the many advantages such as high quality of structural components, less labour intensive at the construction site, and shorter completion time of a project. One of the constraints in precast concrete structures is to ensure that the connections are strong enough to ensure the structural integrity and robustness of the overall frames. In this study, a total of nine rectangular steel splice-sleeve connections were tested experimentally under incremental tensile loads. Two steel plates were inserted and welded to each end of the steel splice-sleeve. The steel plates act as shear key to provide the interlocking mechanism to the grout and to enhance the bond property between the grout and the splice. These plates were adopted to prevent the grout slippage from the sleeve. The grout strength, embedded steel bar lengths and the size of the steel sleeve splice were varied among the specimens to study their effect on the tensile performance of the connection. The results showed that the higher strength of grout, longer embedded length of steel bar and smaller size of the sleeve contributes to a higher ultimate tensile load.

scholarly journals Hysteretic Response of Tilt-Up Concrete Precast Walls with Embedded Steel Plate Connections

2020 ◽  
Vol 12 (19) ◽  
pp. 7907
Author(s):  
Hyun-Do Yun ◽  
Hye-Ran Kim ◽  
Won-Chang Choi
Keyword(s):  
Prestressed Concrete ◽  
Structural Integrity ◽  
Precast Concrete ◽  
American Concrete Institute ◽  
Steel Plates ◽  
Test Results ◽  
Wall Panel ◽  
Concrete Wall ◽  
Concrete Panels ◽  
Wall Panels

Many connection systems are available that can transfer tension and shear loads from a precast concrete wall panel to a floor slab. However, due to the insufficient anchor depth in relatively thin precast concrete panels, it is difficult to attain adequate ductility and stiffness to ensure structural integrity. Based on the authors’ previous research results, the supplementary reinforcement of embedded steel plates in precast concrete wall panels can enhance stiffness while maintaining allowable displacement and ductility. In this study, three full-size tilt-up precast concrete panels with embedded steel plates were fabricated. Lateral cyclic loads were applied to full support structures consisting of a precast concrete wall panel and a foundation. The test results were compared with the results predicted using existing code equations found in the American Concrete Institute 318-14 and the Prestressed Concrete Institute Handbooks. The test results confirm that the supplementary reinforcement of thin precast concrete wall panels can provide (i) the required strength based on current code equations, (ii) sufficient ductility, and (iii) the energy dissipation capacity to resist cyclic loading.

scholarly journals Experimental Study on Novel Energy-Dissipating Prefabricated Beam-Column Joints

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Qiong Liu ◽  
Shanghong Chen ◽  
Wei Lin ◽  
Fanjin Zeng
Keyword(s):  
Shear Failure ◽  
Structural Integrity ◽  
Plastic Hinge ◽  
High Strength ◽  
Internal Force ◽  
Steel Plates ◽  
Engineering Structures ◽  
Anchor System ◽  
Steel Bar ◽  
New Type

A new dapped-end beam to column connection is designed in this paper. Its assembly connection zone changes from inside the joint to midspan of the beam. The proposed connection can not only provide good structural integrity but also ensure that the plastic hinge moves away from the column edge. The rotational capacity of the plastic hinge determines the internal force redistribution of the joint and the energy dissipation capacity. The high-strength bolts and steel plates are used to realize connection, further enhancing the rotation of the plastic hinge and minimizing the cast-in-place concrete volume. Three full-scale exterior beam to column joints are casted and then subjected to reversal cyclic loading. The finite element (FE) analyses are carried out to compare with experimental results and study the effect of connection position on the structural behaviours. The obtained results show that the plastic hinges of all three specimens are firstly developed to a distance from the column edge, thus revealing that this kind of joint can achieve beam hinge mechanism and prevent joint shear failure. And the connection position is the most disadvantaged when coinciding with the plastic hinge zone, which would result in the excessive deformation and the early failure of the steel bar anchor system. The new type of joint shows good seismic performance during earthquake if the connection can be properly designed, and thus this kind of structural form can be applied to actual engineering structures in seismic regions.

Grouted Pipe with Double Spirals for Precast Concrete Connections

2015 ◽  
Vol 789-790 ◽  
pp. 1134-1139
Author(s):  
Ahmad Baharuddin Abd Rahman ◽  
Goh Hiang Miang ◽  
Yusof Ahmad
Keyword(s):  
Bond Strength ◽  
Precast Concrete ◽  
Steel Pipes ◽  
Axial Tension ◽  
Steel Bar ◽  
Tensile Performance ◽  
Connection System ◽  
Double Spiral ◽  
Bar Diameter

This paper presents the pullout performance of grouted splice connections made with steel pipes and double spirals in connecting high tensile steel deformed bars. The parameters studied were the steel bar embedded lengths, grout strength and diameter of the pipe in influencing the tensile performance of the splice connections. A total of nine proposed grouted spiral connections with double spirals were tested under increasing axial tension until failure. The results indicated that the use of double spiral combined with grout strength of at least 60 N/mm2 and main steel bar embedded length of 10 times bar diameter could provide adequate bond strength to form a satisfactory precast connection system.

Analysis and Interpretation of Test Beam Data

2018 ◽  
Author(s):  
Richard Wigmans
Keyword(s):  
Energy Resolution ◽  
Particle Physics ◽  
Particle Beam ◽  
Test Beam ◽  
Term Energy ◽  
The Many ◽  
Physics Experiment ◽  
The Way

This chapter describes some of the many pitfalls that may be encountered when developing the calorimeter system for a particle physics experiment. Several of the examples chosen for this chapter are based on the author’s own experience. Typically, the performance of a new calorimeter is tested in a particle beam provided by an accelerator. The potential pitfalls encountered in correctly assessing this performance both concern the analysis and the interpretation of the data collected in such tests. The analysis should be carried out with unbiased event samples. Several consequences of violating this principle are illustrated with practical examples. For the interpretation of the results, it is very important to realize that the conditions in a testbeam are fundamentally different than in practice. This has consequences for the meaning of the term “energy resolution”. It is shown that the way in which the results of beam tests are quoted may create a misleading impression of the quality of the tested instrument.

scholarly journals Does Tenure Security Reduce Disaster Risk? A Comparative Study of the Nairobi Settlements of Kibera and Kawangware

2021 ◽  
Author(s):  
Rónán McDermott ◽  
Pat Gibbons ◽  
Dalmas Ochieng ◽  
Charles Owuor Olungah ◽  
Desire Mpanje
Keyword(s):  
Structural Integrity ◽  
Disaster Risk ◽  
Comparative Case Study ◽  
Complex Relationship ◽  
Tenure Security ◽  
Household Level ◽  
Urban Informal Settlements ◽  
The Relationship

AbstractWhile scholarship suggests that improving tenure security and housing significantly reduces disaster risk at the household level within urban settings, this assertion has not been adequately tested. Tenure security can be conceived as being composed of three interrelated and overlapping forms: tenure security as determined by legal systems; de facto tenure security; and tenure security as perceived by residents. This article traces the relationship between tenure security, the quality of housing, and disaster risk on the basis of a mixed methods comparative case study of the settlements of Kawangware and Kibera in Nairobi. Although the findings suggest that owner-occupancy is associated with the structural integrity of dwellings to a greater extent than tenantship, no association was found between the length of occupancy by households and the structural integrity of the dwelling. Moreover, tenantship is not found to be closely associated with fires and flooding affecting the dwelling as extant scholarship would suggest. Formal ownership is linked with greater investment and upgrading of property with significant implications for disaster risk. Our findings highlight the complex relationship between tenure security and disaster risk in urban informal settlements and provide impetus for further investigation.

Answers and Questions: Evans-Pritchard On Nuer Religion

1983 ◽  
Vol 14 (3) ◽  
pp. 167-186 ◽  
Author(s):  
John W. Burton
Keyword(s):  
Catholic Church ◽  
Logical Consistency ◽  
Anthropological Study ◽  
The Status ◽  
The Many ◽  
The Catholic Church

AbstractIf my discernment of the thought that underlies his study of Nuer religion is not entirely misconstrued, then one can assert a logical consistency between Collingwood's methodology for history and Evans-Pritchard's for ethnography. It is worthwhile, in that light, to consider the fact that "at one time Evans-Pritchard contemplated writing Collingwood's biography" (Beidelman 1974:559). One commentator, (Kuper 1980:118) typifies this methodology as "postwar idealism" and suggests that the major works he published in the later decades of his presence at Oxford demonstrate the "sterility" of his methodology and theory. Still others have hinted that his entry into the Catholic Church was later reflected in his depiction of Nuer religous life. These are remarkable assertions, when one takes the time to reflect on the many ways in which his own approach and writings have so profoundly influenced the direction of anthropological enquiry in his own country and abroad. The fact is, one can no longer write ethnography in lieu of a solid understanding of the historical circumstances which have resulted in the contemporary 'ethnographic present'. At the same time, practitioners of the discipline have addressed from almost every angle the proposition that all ethnography is indeed a good part confession-that we write what we are able to see. That is precisely the quality of the work that will guarantee the status of Nuer religion as a classic. The methods of history and anthropology can only become more similar. Anyone who holds an absence of definition or presumed repugnance toward theory as criticisms of his contributions, has truly lost the forest for the trees. It is all the more remarkable that his methodological and theoretical advances in the anthropological study of religion are to be found not in his answers, but in the questions he raised.10

A Rank Order of Eateries: A Chicago Stochastic Model

1974 ◽  
Vol 7 (02) ◽  
pp. 165-174
Author(s):  
Donald H. Haider
Keyword(s):  
New York ◽  
Stochastic Model ◽  
Rank Order ◽  
The Many ◽  
New Yorkers

.... The hands of men took hold and tugged And the breaths of men went into the junk And the junk stood up into skyscrapers and asked Who am I? Am I a city?Carl Sandburg-“The Windy City”Robert Merriam, picking up where his father left off, once indicated that it would take 50 years for an aroused citizenry to root out corruption in Chicago. It has taken at least that long to upgrade Chicago's restaurants. Several decades ago, top gourmet societies labelled Chicago a “gastronomic wasteland.” Among the many old clichés and modern prejudices that the Windy City is constantly seeking to outlive is the quality of its restaurants. New Yorkers, of course, will not let old myths die. Gail Green,New York Magazinegalloping gourmet, recently went away from Chicago dubbing its restaurants the “Big Potato” — homely and solid, mealy and bland. Chicago epicureans responded by a whirlwind tour of the Gotham Town's “Best and Most Delectable,” writing devastating critiques of New York's much overrated eating places. If one can transcend these diatribes and gastronomic polemics, you will find Chicago to be as good a dining town as there is in the U.S.A. — variety, service, and prices.

Structural Integrity Assessment of Free-Fall Lifeboats by Combining Fast Monte-Carlo Simulations With CFD by Means of Proxy Load Variables

2016 ◽  
Author(s):  
Sébastien Fouques ◽  
Ole Andreas Hermundstad
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Structural Integrity ◽  
Free Fall ◽  
Integrity Assessment ◽  
Proxy Variables ◽  
Pressure Load ◽  
Calm Water ◽  
Measured Pressure

The paper is concerned with the launch of free-fall lifeboats (FFL). It proposes a method that complies with the DNV-OS-E406 standard in order to select characteristic launches from Monte Carlo simulations for further structural load assessment with CFD and FEM. Proxy variables derived from kinematic parameters and aiming at predicting pressure load indicators are computed with the VARUNA launch simulator developed by MARINTEK. The statistical distributions of the proxy variables obtained from the Monte Carlo simulations are used to identify critical scenarios, and characteristic launches can then be selected from a chosen probability level. The feasibility of the proposed method is documented in the paper for several types of pressure loads. Existing model test data from various FFL-launch campaigns in calm water and in waves are used to compute the proxy variables as it would be done in the VARUNA simulator. Scatter diagrams showing the correlation with actual measured pressure load indicators are then established to assess the quality of the chosen proxy variables.

Influence Parameters Analysis of Forming Quality and System Dynamics Simulation of Vertical Steel Bar Benting

2013 ◽  
Vol 483 ◽  
pp. 280-284
Author(s):  
Xi Jian Zheng ◽  
Xin Zhuo Wang ◽  
Jin Meng Zhang ◽  
Yu Fei Zhu
Keyword(s):  
Simulation Analysis ◽  
Reference Value ◽  
Dynamics Simulation ◽  
Forming Quality ◽  
Steel Bar ◽  
New Process ◽  
Cutting Length ◽  
Bending Radius ◽  
The Relationship

The vertical steel bar bending forming is a kind of new process of bending method. The bending speed, bending radius and clamping length H which is the parameters of vertical steel bar bending machine , is directly affect the quality of bending forming parts. This paper calculated the length of reinforcement before being incised and the springback angle of bending steel bar which obtained the reasonable cutting length and bending Angle; Then based on rigid-flexible virtual prototype technology to build the dynamics model of vertical steel bar bending system. Through simulation analysis ,it obtained the relationship between bending speed, bending radius , clamping length H and forming quality of bending steel bar. In this paper, the analysis method have reference value to the design of similar steel bar bending machines.

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