Modelling in situ shear strength testing of asphalt concrete pavements using the finite element method

2001 ◽  
Vol 28 (3) ◽  
pp. 541-544 ◽  
Author(s):  
Wael Bekheet ◽  
Yasser Hassan ◽  
AO Abd El Halim
Keyword(s):  
Finite Element ◽  
Shear Strength ◽  
Traffic Safety ◽  
Asphalt Concrete ◽  
Material Properties ◽  
Fundamental Property ◽  
Analytical Models ◽  
Strength Testing ◽  
Concrete Pavements

Rutting is one of the well-recognized road surface distresses in asphalt concrete pavements that can affect the pavement service life and traffic safety. Previous studies have shown that the shear strength of asphalt concrete pavements is a fundamental property in resisting rutting. Laboratory investigation has shown that improving the shear strength of the asphalt concrete mix can reduce surface rutting by more than 30%, and the SUPERPAVE mix design method has acknowledged the importance of the shear resistance of asphalt mixes as a fundamental property in resisting deformation of the pavement. An in situ shear strength testing facility was developed at Carleton University, and a more advanced version of this facility is currently under development in cooperation with the Transportation Research Board and the Ontario Ministry of Transportation. In using this facility, a circular area of the pavement surface is forced to rotate about a normal axis by applying a torque on a circular plate bonded to the surface. The pavement shear strength is then related to the maximum torque. This problem has been solved mathematically in the literature for a linear, homogeneous, and isotropic material. However, the models for other material properties are mathematically complicated and are not applicable to all cases of material properties. Therefore, developing a model that can accurately analyze the behaviour of asphalt concrete pavements during the in situ shear test has proven pivotal. This paper presents the development of a three-dimensional finite element model that can simulate the forces applied while measuring the shear strength of the asphalt concrete pavement. A comparison between the model results and those obtained from available analytical models and field measurements proved the accuracy of the developed model.Key words: shear strength, in situ testing, finite element, asphalt, pavement, modelling.

scholarly journals Micromechanical modeling of 8-harness satin weave glass fiber-reinforced composites

2016 ◽  
Vol 51 (5) ◽  
pp. 705-720 ◽  
Author(s):  
RS Choudhry ◽  
Kamran A Khan ◽  
Sohaib Z Khan ◽  
Muhammad A Khan ◽  
Abid Hassan
Keyword(s):  
Finite Element ◽  
Glass Fiber ◽  
Material Properties ◽  
Micromechanical Model ◽  
Unit Cell ◽  
Micromechanical Modeling ◽  
Void Content ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced

This study introduces a unit cell-based finite element micromechanical model that accounts for correct post cure fabric geometry, in situ material properties and void content within the composite to accurately predict the effective elastic orthotropic properties of 8-harness satin weave glass fiber-reinforced phenolic composites. The micromechanical model utilizes a correct post cure internal architecture of weave, which was obtained through X-ray microtomography tests. Moreover, it utilizes an analytical expression to update the input material properties to account for in situ effects of resin distribution within yarn (the yarn volume fraction) and void content on yarn and matrix properties. This is generally not considered in modeling approaches available in literature and in particular, it has not been demonstrated before for finite element micromechanics models of 8-harness satin weave composites. The unit cell method is used to obtain the effective responses by applying periodic boundary conditions. The outcome of the analysis based on the proposed model is validated through experiments. After validation, the micromechanical model was further utilized to predict the unknown effective properties of the same composite.

Performance of double skin-profiled composite shear walls — experiments and design equations

2004 ◽  
Vol 31 (2) ◽  
pp. 204-217 ◽  
Author(s):  
K M. Anwar Hossain ◽  
H D Wright
Keyword(s):  
Finite Element ◽  
Shear Strength ◽  
Failure Modes ◽  
Shear Walls ◽  
Shear Stiffness ◽  
Response Strength ◽  
Shear Loading ◽  
Analytical Models ◽  
Small Scale ◽  
Composite Wall

The novel form of composite walling system consists of two skins of profiled steel sheeting with an infill of concrete. The knowledge of the behaviour of such walling under shear loading is important to use this system as shear elements in a steel framed building. Currently design provisions for this novel form of framed shear walling do not exist. This paper presents the results of tests on one-sixth scale models of the composite wall and its components, manufactured from very thin sheeting and microconcrete. The heavily instrumented small-scale tests provided information on the load–deflection response, strength, stiffness, strain condition, sheet–concrete interaction, and failure modes. Analytical models for the shear strength and stiffness of the wall are derived. The adequacy of design equations is validated through experimental results and finite element modelling.Key words: composite wall, design equation, profiled sheeting, shear strength, shear stiffness, strain, buckling, finite element, interface, microconcrete.

Nanotechnology Future and Present in Construction Industry

2016 ◽  
pp. 141-179
Author(s):  
Umair Hasan ◽  
Amin Chegenizadeh ◽  
Hamid Nikraz
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Finite Element ◽  
Natural Hazards ◽  
Finite Element Methods ◽  
Material Behavior ◽  
Concrete Pavements ◽  
Metallic Oxides ◽  
Subgrade Stabilization

After the introduction of nanotechnology, it has been widely researched in geotechnical engineering field. This chapter aims to study these advancements with specific focus on geotechnical applications. In-situ probing of soil and rock masses through nanomaterials may help in providing better safeguards against natural hazards. The molecular dynamics and finite element methods may also be used for the modelling of the nanostructures to better understand the material behavior, causing a bottom-up approach from nano to macroscopic simulations. Nanoclays, nano-metallic oxides and fibers (carbon nanotubes) can enhance the mechanical characteristics of weak, reactive and soft soils. Nanomaterials may also be used for improving the performance of reinforced concrete pavements by enhancing the thermal, mechanical and electrical characteristics of the concrete mixes. The chapter presents a review of the current researches and practices in the nano-probing, nanoscale modelling and application of nanomaterials for soil, pavement concrete mortar and subgrade stabilization.

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