Design of Bitumen Asphalt Belt Sliding Joint Based on Experiment Results

2017 ◽  
Vol 738 ◽  
pp. 185-194
Author(s):  
Pavlina Matečková ◽  
Martina Smirakova ◽  
Jan Kubosek ◽  
Radim Čajka
Keyword(s):  
Underground Mining ◽  
Fem Analysis ◽  
Shear Resistance ◽  
Test Results ◽  
Horizontal Deformation ◽  
Normal Forces ◽  
Sliding Joint ◽  
Undermined Area ◽  
Sliding Joints ◽  
Foundation Structure

Foundation structures are usually exposed to dominant vertical load. However, in some cases there is also significant value of horizontal load caused e.g. by horizontal terrain deformation on areas attached with underground mining or by horizontal deformation of foundation structure due to pre-stressing, creep, shrinkage, and temperature variation. Through the friction between subsoil and foundations, the foundation structure must resist significant normal forces. The idea of sliding joints between subsoil and foundation structure, which eliminates the friction in footing bottom, comes from the 1970’s. The bitumen asphalt belt given rheological properties has been proven as an effective material for sliding joints. In the paper there are test results of shear resistance of currently used asphalt belts. The test results are used for subsoil shear stress analysis in model example of strip foundation. Shear resistance is calculated according to Czech code for designing buildings on undermined area and also using advanced FEM analysis.

Bitumen Sliding Joints for Friction Elimination in Footing Bottom

2012 ◽  
Vol 188 ◽  
pp. 247-252 ◽  
Author(s):  
Radim Čajka ◽  
Pavlina Matečková ◽  
Martina Smirakova
Keyword(s):  
Underground Mining ◽  
Shear Resistance ◽  
Temperature Deformation ◽  
Horizontal Deformation ◽  
Shrinkage Temperature ◽  
Stress Strain Relation ◽  
Deformation Velocity ◽  
Sliding Joint ◽  
Sliding Joints ◽  
Foundation Structure

Use of a sliding joint is an effective method to decrease the stress in foundation structure where there is a horizontal deformation of subsoil (areas afflicted with underground mining) or horizontal deformation of a foundation structure (pre-stressed foundations, creep, shrinkage, temperature deformation). A convenient material for a sliding joint is a bitumen asphalt belt. Experiments for different types of bitumen belts were undertaken at the Faculty of Civil Engineering - VSB Technical University of Ostrava in 2008. Since 2011 an extension of the 2008 experiments has been in progress and the shear resistance of a slide joint is being tested as a function of temperature in a temperature controlled room. In this paper experimental results of temperature dependant shear resistance are presented. The result of the experiments should be the sliding joint shear resistance as a function of deformation velocity and temperature. This relationship is used for numerical analysis of stress/strain relation between foundation structure and subsoil.

New Knowledge in the Field of Reduction of Shear Stress in the Foundation Structures of Concrete or Masonry Structures

2014 ◽  
Vol 1082 ◽  
pp. 224-229
Author(s):  
Martina Smirakova
Keyword(s):  
Laboratory Tests ◽  
Mechanical Load ◽  
Thermal Sensitivity ◽  
Masonry Structures ◽  
Horizontal Deformation ◽  
Friction Forces ◽  
Sliding Joint ◽  
Real Behavior ◽  
Sliding Joints ◽  
Foundation Structure

This paper deals with application of sliding joint into foundation structures which can be very helpful in case that the foundation structure is exposed to effect of relative horizontal deformation. These deformations can be created direct in the structure from the effect of creep or shrinkage of concrete, from the effect of pre-stressing of foundation structure or they can arise in the subsoil as a consequence of undermining. Sliding joints are often created from asphalt belts which help to increase of friction forces in the foundation bottom. Due to fact that today ́s market gives a lot of new modern materials, the laboratory tests are carried out to verify their behavior at the Faculty of Civil Engineering VŠB Technical University of Ostrava (Czech Republic). The basic principle of these tests is to simulate real behavior sliding joint in foundation structure and great attention is also focused on thermal sensitivity of majority of used materials. Thermal sensitivity at the action of mechanical load relates closely with their rheological properties. Rheology is the science about deformation of substances in the dependence on time and it helps to describe difficult materials using simpler rheological materials models. A right created rheological model of asphalt belt could be used to prediction of behavior of sliding joint with regard to time of loading and ambient temperature. The knowledge of change of asphalt belt behavior consequently to temperature change could be used in the future to design of this type sliding joint where the temperature will be not only monitored but also managed in the dependence on necessity of increasing or decreasing of shear resistance. Partial results from laboratory tests as well as current conclusion will be presented in this paper.

Comparison of the Shear Resistance in the Sliding Joint between Asphalt Belts and Modern PVC Foils

2014 ◽  
Vol 501-504 ◽  
pp. 945-948 ◽  
Author(s):  
Martina Smirakova
Keyword(s):  
Ambient Temperature ◽  
Civil Engineering ◽  
Shear Resistance ◽  
Temperature Dependency ◽  
Horizontal Deformation ◽  
Sliding Joint ◽  
Different Types ◽  
Different Temperatures ◽  
Foundation Structure

This paper deals with sliding joint in the foundation structure. Application of sliding joint into foundation structure is an effective method to reduce effect of horizontal deformation of foundations. These can arise from effect of undermining or from shrinkage or creep of concrete. A different material can be used to create sliding joint but some are advantageous and some are not. It is often used an asphalt belt or newly different modern foils are used too. Different types of asphalt belts are tested at Faculty of Civil Engineering at different loads and at different temperatures. Some foils are tested too. The effect of ambient temperature is monitored to better description of temperature dependency of asphalt belts. Long-term goal of this research is to simplify process of design buildings with sliding joint and to help designer with right choice of the most advantageous material.

Sliding Joints from Traditional Asphalt Belts

2014 ◽  
Vol 1020 ◽  
pp. 335-340 ◽  
Author(s):  
Martina Smirakova ◽  
Marie Stara ◽  
Petr Mynarčík
Keyword(s):  
Laboratory Test ◽  
Rheological Properties ◽  
Laboratory Tests ◽  
Base Layer ◽  
Horizontal Deformation ◽  
Existing Building ◽  
Sliding Joint ◽  
Different Temperatures ◽  
Correct Function ◽  
Sliding Joints

Problems with horizontal deformation in the subsoil are often solved for building on undermined areas not only in our region. There are many ways to solve this problem. The existing building can be draw together in total or stiffened belt can be carried out around the structure foundation. But the best solution is that which is carried out beforehand. One of the methods which can be applied beforehand is using of sliding joint with using of rheological properties of asphalt. The basic principle of this method lies on application an asphalt belts or another material between foundation and subsoil. It is also created concrete base layer between sliding layer and subsoil to ensure base flatness and to protect of sliding layer material. The type of material is important for correct function of sliding joint and there are very often used the rheological properties of traditional asphalt belts. The laboratory tests are carried out at the Faculty of Civil Engineering VŠB-Technical University of Ostrava to verify their rheological behavior at different loads and different temperatures. Following the test there is the effort to use of obtained values to other calculations and there is effort to contribute to innovation of currently method of design which is based on old materials from the 80th. The principle and the results from the laboratory test as well as current conclusions will be presented in this paper.

scholarly journals Enhanced Drag Reduction Performance of Nanocomposites: The Effects of Surface Modification of Nano Silica

2017 ◽  
Vol 26 (4) ◽  
pp. 096369351702600 ◽  
Author(s):  
Xiaodong Dai ◽  
Guicai Zhang ◽  
Bing Li ◽  
Jijiang Ge ◽  
Xuewu Wang ◽  
...  
Keyword(s):  
Surface Modification ◽  
Drag Reduction ◽  
Rotating Disk ◽  
Shear Resistance ◽  
Test Results ◽  
Nano Silica ◽  
Surface Hydroxyl ◽  
Adsorption Analysis ◽  
Oil Adsorption ◽  
Loop 2

In this paper, nanocomposite was synthesized with nano silica and poly-α-olefin, and the effects of surface modification to the nano silica on its drag reduction performance were investigated. The dosage coupling agent, Y-aminopropyltriethoxysilane, and the modification temperature were studied intensively through surface hydroxyl and oil adsorption analysis. The test results indicated that the hydroxyl number of the silica was decreased by Y-aminopropyltriethoxysilane modification, with improved lipophilicity and oil adsorption. At 50°C, the optimum Y-aminopropyltriethoxysilane dosages were 15% for Nano-Si-10, 5% for Nano-Si-20, and 10% for Degussa-R972. The modification significantly changed the nano silica surface properties and enhanced the interaction with poly-α-olefin. Through drag reduction and shear resistance tests by rotating disk 40 mins degradation and testing loop 2 times shearing, it was shown that the nanocomposite possessed good drag reduction and excellent shear resistance properties.

Buckling/Ultimate Strength Evaluation for Continuous Stiffened Panel Under Combined Shear and Thrust

2016 ◽  
Author(s):  
Hiroaki Ogawa ◽  
Tomoki Takami ◽  
Akira Tatsumi ◽  
Yoshiteru Tanaka ◽  
Shinichi Hirakawa ◽  
...  
Keyword(s):  
Ultimate Strength ◽  
Fem Analysis ◽  
Strength Analysis ◽  
Stiffened Panel ◽  
Fe Modeling ◽  
Test Results ◽  
Strength Evaluation ◽  
Shear Buckling ◽  
Collapse Behavior ◽  
Good Agreement

In this study, FE modeling method for the buckling/ultimate strength analysis of a continuous stiffened panel under combined shear and thrust is proposed. In order to validate the proposed method, shear buckling collapse tests of a stiffened panel and FEM analysis are carried out. As the result of these, it is confirmed that the buckling collapse behavior and the ultimate strength estimated by the proposed method are in good agreement with the test results.

Direct and Flexural Shear Strength of Composite Beam with Perforbond Rib

2018 ◽  
Vol 26 (1) ◽  
pp. 9-18
Author(s):  
Dooyong Cho ◽  
Jinwoong Choi ◽  
Hoseong Jeong
Keyword(s):  
Shear Stress ◽  
Shear Test ◽  
Shear Resistance ◽  
Shear Behavior ◽  
Flexural Behavior ◽  
Direct Shear ◽  
Test Results ◽  
Shear Connectors ◽  
The Difference ◽  
Push Out

When Perfobond Rib shear connectors are used as flexural materials in structures such as bridges, they show flexural shear behavior due to external force, rather than direct shear behavior. The aim of this study is thus to analyze the difference between both behaviors. First, we prepared a specimen to analyze direct shear behavior using Perfobond Rib shear connectors, analyzed the characteristics of behavior with a push-out test and proposed a formula of shear resistance assessment. Proposed formula shows a relatively good fit with less than 10% error. A flexural shear test was then conducted based on the result of the direct shear test. Based on the static flexural test it analyzed the flexural behavior and the flexural shear stress it calculated. Direct shear stress and EN 1994-1-1 to lead and be calculated, it compared the flexural shear stress and it analyzed in about the shear resistance stress which it follows in load direction. Finally, we compared both test results, and the comparison showed that the flexural shear stress is approximately 6% stronger than the direct shear stress.

Study on Aluminum Alloy Helicopter Deck under Static Loads

2014 ◽  
Vol 926-930 ◽  
pp. 889-895
Author(s):  
An Tao Feng ◽  
Xin Gang Zhou
Keyword(s):  
Aluminum Alloy ◽  
Sandwich Panel ◽  
Static Load ◽  
Mechanical Performance ◽  
Fem Simulation ◽  
Fem Analysis ◽  
Test Results ◽  
Compressive Loads ◽  
Ultimate Load Carrying Capacity ◽  
Load Conditions

Test and study of aluminum alloy helicopter deck under static load were carried out. The deck is made of aluminum alloy sandwich panel. In the experiment, the deflection and stress of deck are measured under different static load conditions. Load conditions are determined by the conditions that helicopter berths at the deck. When helicopter berths at the deck, the deck endures vertical compressive loads on the deck surface and diagonal tension loads on the tie-down rod which is used to fasten the helicopter. According to the test results under different load conditions, the characteristic behavior and ultimate load carrying capacity were analyzed. Based on experimental results, FEM simulation was made. The results of FEM analysis was agreed with the test results very well. It is shown that the helicopter deck which is composed of aluminum alloy sandwich panel has good mechanical performance.

Equations for Four-Bar Line-Envelopes

1981 ◽  
Vol 103 (4) ◽  
pp. 743-749 ◽  
Author(s):  
K. H. Hunt ◽  
E. F. Fichter
Keyword(s):  
The Other ◽  
Straight Line ◽  
Sliding Joint ◽  
Line Equation ◽  
Four Bar Linkage ◽  
Sliding Joints

A line-equation (in tangential coordinates) is derived for the envelope of a general straight line attached to the coupler of a planar hinged four-bar linkage. Since a line can be identified with an axis of relative translation parallel to a sliding joint, the study of how lines move in a mechanism has practical potential. Nevertheless the emphasis here is on the geometry of the line-envelopes, and some envelopes are plotted both as samples of what can be obtained and to exemplify some of the properties which they possess. Towards the end of the paper all the other forms of planar four-bar linkage, namely those in which one or two sliding joints replace hinges, are examined, and their envelope-equations are presented.

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