Resilient Modulus and Permanent Deformation Testing of Unbound Granular Materials

Resilient Modulus and Permanent Deformation Testing of Unbound Granular Materials
Author: Anuroopa Kancherla
Publisher:
Total Pages:
Release: 2005
Genre:
ISBN:

Numerous research efforts have been devoted to characterizing the behavior of granular materials, which is one of the main concerns of pavement engineers. For better understanding of this behavior, laboratory tests where in-situ stress conditions and traffic loads are adequately simulated are needed. This study makes use of an expanded test protocol called a performance test that includes resilient modulus as well as permanent deformation testing. This test protocol determines three nonlinear resilient modulus parameters (k1, k2, k3) and two permanent deformation parameters ([alpha], [mu]). The resilient modulus test results are required inputs in the Level 1 analysis of the proposed American Association of State Highway and Transportation Officials (AASHTO) Pavement Design Guide. In addition, both resilient modulus and permanent deformation test results provide material property inputs to pavement performance prediction models. This study also evaluated the within laboratory repeatability of the performance test and developed a within laboratory precision statement. Further, a statistical analysis was conducted on the test results to estimate the number of test specimens required for testing for specific reliability levels. Two test specimens are required for a reliability level of 15%. A within laboratory study was also conducted to investigate the influence of specimen size on test results. The specimen height was reduced from 12 in. (304 mm) to 8 in. (203 mm), and there was no difference in test results at a confidence level of 95%. The performance test was further used successfully in subsequent studies to evaluate the behavior of granular materials and the influence of various factors on their behavior. As fines content increased, the resilient modulus values decreased and permanent deformation increased. As the moisture content increased, the resilient modulus value decreased and the resistance to permanent deformation decreased. A simplified laboratory measurement tool that is repeatable, relatively cheap and easy to perform might prompt the use of laboratory measured values of resilient modulus in pavement design and facilitate correlation of these values to field measured values on a large scale. Use of measured data for the base properties rather than estimates would insure improved pavement designs and, in many cases, would save money in construction costs.

Austroads repeated load triaxial test method

Austroads repeated load triaxial test method
Author:
Publisher:
Total Pages: 25
Release: 2000
Genre:
ISBN:

There is a need for performance characterisation indices and performance-based specifications of unbound materials. In addition, there is a need to address issues associated with the non-uniformity of current empirical specifications adopted by different AUSTROADS Member Authorities, with a view to developing more uniform national performance-based specifications using a framework based on mechanistic design procedures. Repeat load triaxial (RLT) testing equipment and test procedures have been developed and evaluated in NSRP Project N&T 9529 - Stage 1) and current specifications for standard unbound materials (Project T&E P133) are being reviewed. The objective of the NSRP Project N.T.&E 9906 during 1999/2000 is to establish a framework for incorporating the RLT test method into performance-based specifications and pavement design of unbound pavement materials. This report describes the interim AUSTROADS test protocols for the determination of permanent deformation and resilient modulus characteristics of unbound pavement materials under drained conditions, which can be used for the purposes of material specifications and pavement design.

HRIS Abstracts

HRIS Abstracts
Author: National Research Council (U.S.). Highway Research Board
Publisher:
Total Pages: 1116
Release: 1983
Genre: Highway engineering
ISBN:

Developing a Virtual Test Environment for Granular Materials Using Dem

Developing a Virtual Test Environment for Granular Materials Using Dem
Author: Liang Cui
Publisher: LAP Lambert Academic Publishing
Total Pages: 392
Release: 2010-10
Genre:
ISBN: 9783843362351

Discrete element methods (DEM) are promising numerical methods for analysing the complexities of granular material response as they can consider the particle scale interactions in these materials. In this book a virtual test environment was developed for granular materials using DEM. Two fundamental geotechnical laboratory tests, the direct shear test and the triaxial test, were implemented in this virtual test environment. This test environment was validated by comparing simulation results with physical experiment results. Further DEM simulations were then performed to analyse the sensitivity of the macro-scale specimen response to some selected parameters (e.g. particle friction, size distribution). Using the results of the DEM simulations, comprehensive analyses of the particle scale parameters were performed to explore the relationship between the observed macro-scale specimen response and the particle scale interactions, including the internal stresses, the contact forces, the fabric, and the particle displacements.

The Physics Of The Deformation Of Densely Packed Granular Materials

The Physics Of The Deformation Of Densely Packed Granular Materials
Author: Maarten Anton (Curt) Koenders
Publisher: World Scientific
Total Pages: 226
Release: 2020-03-10
Genre: Technology & Engineering
ISBN: 178634825X

This book is of interest for those that are concerned professionally with granular materials: civil engineers, geologists and geophysicists, chemical engineers, pharmacists, food technologists, agriculturalists, biologists and astronomers.Granular materials play a role in nearly all human activities. For example, users of sand, from children in sandpits to sophisticated geotechnical engineers, know that it is a fascinating — and to some extent, unpredictable — material. In addition to sand, which itself may be of many compositions, there are various types of materials including gravel, fine-particle aggregates as employed in cosmetics, pharmaceuticals, dust, crushed rock and granules that occur in a domestic environment, such as breakfast cereals, sugar, salt and (instant or ground) coffee granules.The aim of the book is to present a theory that explains the physics behind the phenomena during the deformation of densely packed granular media. The physics that describes such features is rather subtle and is developed from the micro to macro level (the latter is the continuum mechanics level that is used in practical applications). It requires the analysis of anisotropy and the heterogeneity of the packing evaluated against the background of a frictional inter-particle interaction.

Recent Advances in Civil Engineering

Recent Advances in Civil Engineering
Author: Lakshman Nandagiri
Publisher: Springer Nature
Total Pages: 1088
Release: 2022-06-26
Genre: Technology & Engineering
ISBN: 9811918627

This book presents the select proceedings of the International Conference on Civil Engineering Trends and Challenges for Sustainability (CTCS 2021). It discusses emerging and latest research and advances in sustainability in different areas of civil engineering, providing solutions to sustainable development. Various topics covered include sustainable construction technology & building materials; structural engineering, transportation and traffic engineering, geotechnical engineering, environmental engineering, water resources engineering, remote sensing and GIS applications. This book will be of potential interest to researchers and professionals working in sustainable civil engineering and related fields.

Paving Materials and Pavement Analysis

Paving Materials and Pavement Analysis
Author: American Society of Civil Engineers
Publisher: Amer Society of Civil Engineers
Total Pages: 592
Release: 2010
Genre: Technology & Engineering
ISBN: 9780784411049

Pavement Design And Paving Material Selection are important for efficient, cost effective, durable, and safe transportation infrastructure Paving Materials and Pavement Analysis contains 73 papers examining bound and unbound material characterization, modeling, and performance of highway and airfield pavements. The papers in this publication were presented during the GeoShanghal 2010 International Conference held in Shanghai, China, June 3-5, 2010.