Developing New Design Criteria of Asphalt Pavement Mix Using Nano-Materials and Polymer-Materials

2018 ◽  
pp. 335-347
Author(s):  
Abdelzaher E. A. Mostafa ◽  
Waleed M. F. Tawhed ◽  
Mohamed R. Elshahat ◽  
Alaa G. Sherif
Keyword(s):  
Asphalt Pavement ◽  
Polymer Materials ◽  
Design Criteria ◽  
Nano Materials

Construction Quality Control of Unbound Base Course using Light Weight Deflectometer where Reclaimed Asphalt Pavement Aggregate is Used as an Example

2020 ◽  
Vol 2674 (10) ◽  
pp. 989-1002
Author(s):  
Emre Akmaz ◽  
Saad Ullah ◽  
Burak F. Tanyu ◽  
Erol F. Guler
Keyword(s):  
Quality Control ◽  
Asphalt Pavement ◽  
Field Measurements ◽  
Design Criteria ◽  
Reclaimed Asphalt Pavement ◽  
Light Weight ◽  
Reclaimed Asphalt ◽  
Light Weight Deflectometer ◽  
Base Course ◽  
Unbound Aggregate

Reclaimed asphalt pavement (RAP) is already being recycled as a construction and building material. One of the commonly considered applications is to create an unbound aggregate from this material. However, since the particles of RAP have binder coatings, traditional quality control procedures applied during construction such as use of a nuclear density gauge does not provide accurate results. Therefore there is a need to find another method that can be applied during construction to confirm that the placement in the field meets the design criteria. For this reason, in this study, the suitability of using light weight deflectometer (LWD) has been investigated. The presented methodology outlines how to implement the use of LWD to create a target modulus in the laboratory as part of design criteria and compare with the field measurements. In the field, depending on the thickness of the constructed aggregate layer, the LWD measurements may be influenced by more than just the layer of interest. The presented methodology also provides a solution for such multilayer conditions. Although the study primarily focuses on using RAP as the investigated material, the methodology developed in this study can be applied to any type of unbound aggregate as demonstrated in this study.

Optimal proportioning for hot recycled mix design under Superpave mix design consideration

2009 ◽  
Vol 36 (9) ◽  
pp. 1470-1477 ◽  
Author(s):  
Aravind Krishna Swamy ◽  
Animesh Das
Keyword(s):  
Asphalt Pavement ◽  
Optimal Solution ◽  
Mix Design ◽  
Design Criteria ◽  
Reclaimed Asphalt Pavement ◽  
Design Consideration ◽  
Reclaimed Asphalt ◽  
Total Material ◽  
Mix Proportion ◽  
Fixed Parameter

While performing recycled (central plant) hot mix design as per Superpave mix design criteria, the quantity of reclaimed asphalt pavement (RAP) is either assumed fixed, or estimated from other fixed parameter(s). In either of the cases, the constituent (RAP, virgin binder, and virgin aggregates) proportions may not necessarily represent a cost-optimal situation. The present paper develops a generalized formulation for preliminary constituent proportioning of hot recycled mix following Superpave criteria. Through this formulation an optimal solution for mix proportion can be obtained, where the total material cost is minimized while satisfying all the binder and mix property requirements.

Aging and Fracture Behavior of Polymers

1991 ◽  
Vol 226 ◽  
Author(s):  
A. Chudnovsky ◽  
C.P. Bosnyak
Keyword(s):  
Continuum Mechanics ◽  
Environmental Effects ◽  
Service Time ◽  
Fracture Behavior ◽  
Mechanical Performance ◽  
Mechanical Stresses ◽  
Polymer Materials ◽  
Design Criteria ◽  
Morphological Transformation ◽  
New Approach

AbstractSignificant changes in polymer materials and their subsequent mechanical performance can occur within an expected engineering service time. These changes can be further exacerbated with environmental effects such as with solvents and mechanical stresses. Examples are given of premature field failures which illustrate the inadequacy of existing understanding and design criteria. A new approach is outlined which is based on the coupling of two fundamental concepts; a geometrical representation of material morphology on various scales and thermodynamics of morphological transformation. These concepts allow one to bridge an existing understanding of aging on molecular and morphological levels with a phenomenological continuum mechanics approach.

scholarly journals Research on Fatigue Model of Semi-Rigid Base Asphalt Pavement before and after Polymer Grouting

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Bei Zhang ◽  
Xu Zhang ◽  
Yanhui Zhong ◽  
Xiaolong Li ◽  
Meimei Hao ◽  
...  
Keyword(s):  
Numerical Model ◽  
Service Life ◽  
Fatigue Damage ◽  
Mechanical Response ◽  
Asphalt Pavement ◽  
Damage Model ◽  
Vertical Displacement ◽  
Polymer Materials ◽  
Rigid Base ◽  
Before And After

To improve the service life of a semirigid base asphalt pavement and prolong its service cycle, it is imperative to conduct long-term performance research before and after pavement disease repair. This study proposes a fatigue damage model for pavement and polymer materials and uses the finite element method to establish a three-dimensional numerical model of a semirigid base asphalt pavement structure. Moreover, it compares and analyzes the mechanical response and fatigue damage of this pavement before and after polymer repair. The evolution law is verified by indoor fatigue tests. The results show that, under a standard load of 0.7 MPa, the vertical displacement and the Mises stress of the vacant position after the polymer repair are reduced by 61% and 69%, respectively. Under a cyclic load of 1.2 MPa, the number of load actions increases from 500,000 to more than 5 million, and the fatigue damage factor of the polymer is reduced by 29%. With the increase in the number of fatigue test loads, the cumulative evolution trend of the fatigue damage is basically consistent with the results of the numerical simulation, which verifies the rationality of the numerical model. This research is relevant for providing a reference for extending the service life of expressways and improving the technical level of expressway maintenance.

Electron-diffraction studies in synthetic polymer materials

1983 ◽  
Vol 41 ◽  
pp. 362-365
Author(s):  
D.T. Grubb
Keyword(s):  
Electron Diffraction ◽  
Synthetic Polymer ◽  
Polymer Materials ◽  
Crystallographic Structure ◽  
High Dose ◽  
Electron Dose ◽  
Dose Rates ◽  
First Case ◽  
Diffraction Patterns ◽  
The Many

Diffraction studies in polymeric and other beam sensitive materials may bring to mind the many experiments where diffracted intensity has been used as a measure of the electron dose required to destroy fine structure in the TEM. But this paper is concerned with a range of cases where the diffraction pattern itself contains the important information.In the first case, electron diffraction from paraffins, degraded polyethylene and polyethylene single crystals, all the samples are highly ordered, and their crystallographic structure is well known. The diffraction patterns fade on irradiation and may also change considerably in a-spacing, increasing the unit cell volume on irradiation. The effect is large and continuous far C94H190 paraffin and for PE, while for shorter chains to C 28H58 the change is less, levelling off at high dose, Fig.l. It is also found that the change in a-spacing increases at higher dose rates and at higher irradiation temperatures.

Structure-property relationships of PE/PP sandwiched films

1987 ◽  
Vol 45 ◽  
pp. 454-455
Author(s):  
J. Petermann ◽  
G. Broza ◽  
U. Rieck ◽  
A. Jaballah ◽  
A. Kawaguchi
Keyword(s):  
Mechanical Tests ◽  
Polymer Materials ◽  
Ionic Crystals ◽  
Structure Property ◽  
Polymer Systems ◽  
Structure Property Relationships ◽  
Oriented Films ◽  
Materials Used ◽  
Polymer Laminates ◽  
Heated Glass

Oriented overgrowth of polymer materials onto ionic crystals is well known and recently it was demonstrated that this epitaxial crystallisation can also occur in polymer/polymer systems, under certain conditions. The morphologies and the resulting physical properties of such systems will be presented, especially the influence of epitaxial interfaces on the adhesion of polymer laminates and the mechanical properties of epitaxially crystallized sandwiched layers.Materials used were polyethylene, PE, Lupolen 6021 DX (HDPE) and 1810 D (LDPE) from BASF AG; polypropylene, PP, (PPN) provided by Höchst AG and polybutene-1, PB-1, Vestolen BT from Chemische Werke Hüls. Thin oriented films were prepared according to the method of Petermann and Gohil, by winding up two different polymer films from two separately heated glass-plates simultaneously with the help of a motor driven cylinder. One double layer was used for TEM investigations, while about 1000 sandwiched layers were taken for mechanical tests.

Electron spectroscopic imaging (ESI) on multiphase polymer materials

1989 ◽  
Vol 47 ◽  
pp. 348-349
Author(s):  
H.-J. Cantow ◽  
M. Kunz ◽  
M. Möller
Keyword(s):  
Energy Loss ◽  
Melt Spinning ◽  
Chromatic Aberration ◽  
Element Distribution ◽  
Polymer Materials ◽  
Specific Energy Loss ◽  
Transmission Electron ◽  
Multicomponent Polymer ◽  
Diffraction Patterns ◽  
Image Planes

In transmission electron microscopy the natural contrast of polymers is very low. Thus the contrast has to be enhanced by staining with heavy metals. The resolution is limited by the size of the staining particles and by the fact that electrons with different energy are focused in different image planes due to the chromatic aberration of the magnetic lenses. The integration of an electron energy loss spectrometer into the optical coloumn of a transmission electron microscope offers the possibility to use monoenergetic electrons and to select electrons with a certain energy for imaging. Thus contrast and resolution are enhanced. By imaging only electrons with an element specific energy loss the element distribution in the sample can be obtained. In addition, elastic bright field images and diffraction patterns yield excellent resolution. Some applications of the method on multicomponent polymer materials are discussed.Bulk polymer samples were prepared by ultramicrotoming at room temperature or well below the glass transition temperature. Very thin films for the direct observation of the structure in semicrystalline polymers were obtained by melt-spinning. Specimens were examined with a ZEISS CEM 902 operated at 80 kV.

Quantitative high-resolution electron microscopy (HREM) of defects in ordered polymers

1996 ◽  
Vol 54 ◽  
pp. 166-167
Author(s):  
Patricia M. Wilson ◽  
David C. Martin
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
High Resolution ◽  
Liquid Crystalline ◽  
High Resolution Electron Microscopy ◽  
Polymer Materials ◽  
Scattered Electron ◽  
Crystalline Polymers ◽  
Resolution Electron ◽  
Beam Damage

Efforts in our laboratory and elsewhere have established the utility of low dose high resolution electron microscopy (HREM) for imaging the microstructure of crystalline and liquid crystalline polymers. In a number of polymer systems, direct imaging of the lattice spacings by HREM has provided information about the size, shape, and relative orientation of ordered domains in these materials. However, because of the extent of disorder typical in many polymer microstructures, and because of the sensitivity of most polymer materials to electron beam damage, there have been few studies where the contrast observed in HREM images has been analyzed in a quantitative fashion.Here, we discuss two instances where quantitative information about HREM images has been used to provide new insight about the organization of crystalline polymers in the solid-state. In the first, we study the distortion of the polymer lattice planes near the core of an edge dislocation and compare these results to theories of dislocations in anisotropic and liquid crystalline solids. In the second, we investigate the variations in HREM contrast near the edge of wedge-shaped samples. The polymer used in this study was the diacetylene DCHD, which is stable to electron beam damage (Jc = 20 C/cm2) and highly crystalline. The instrument used in this work was a JEOL 4000 EX HRTEM with a beam blanidng device. More recently, the 4000 EX has been installed with instrumentation for dynamically recording scattered electron beam currents.

Prediction of Temperature Field of Asphalt Pavement Structure

CICTP 2020 ◽  
2020 ◽  
Author(s):  
Zhizhong Zhao ◽  
Mengchen Li ◽  
Yu Wang ◽  
Wenwen Chen ◽  
Yulong Zhao ◽  
...  
Keyword(s):  
Temperature Field ◽  
Asphalt Pavement ◽  
Pavement Structure
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