Estimating resilient modulus of base aggregates for mechanistic-empirical pavement design and performance evaluation

Titi, Hani H.; Matar, Mohammad G.

doi:10.1016/j.trgeo.2018.09.014

Cited by 25 publications

(12 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A logical reason for using the UCT or CBR tests is the relative ease of execution and speed of performing the tests compared to the RLTT, which requires meticulous sample preparation and more sophisticated cyclic triaxial testing equipment (Araya et al 2010;Hoff et al 2005). However, unlike the UCT and CBR investigations, RLTT enables thorough evaluation of the dynamic behavior of the stabilized materials (resilient modulus and resistance against permanent deformation), which is required for incorporation into modern mechanistically based pavement design approaches (Ghadimi and Nikraz 2017;Titi and Matar 2018). Because this study is focused upon the stabilization of the unbound aggregate layer within the pavement and this course is exposed to traffic and environmental loadings, the durability of the stabilized material is very important.…”

Section: Research Motivation and Objectivementioning

confidence: 99%

Stabilization of Coarse Aggregates with Traditional and Nontraditional Additives

Barbieri

Lou

Dyke

et al. 2022

J. Mater. Civ. Eng.

View full text Add to dashboard Cite

High-quality coarse aggregates are routinely used for the surface, base, and subbase layers in paved roads or the surface course in unpaved low-volume roads. Unfortunately, high-quality aggregates meeting stringent material specifications are becoming increasingly costly and difficult to find within reasonable distances of road construction projects. Various stabilization technologies can be employed to improve the mechanical properties of available aggregate materials, providing environmental and economic benefits. This investigation used three laboratory test methods to evaluate and compare all the existing kinds of additive technologies suitable to stabilize a coarse-graded road unbound layer. Two traditional solutions (cement and bitumen) and eleven nontraditional solutions (categorized as either brine salts, clay binders, organic nonpetroleum products, organic petroleum products, or synthetic polymers) were included. Repeated load triaxial tests were performed to evaluate the dynamic behavior of the untreated and treated aggregates in terms of their resilient modulus and the resistance against permanent deformation. A modified version of the rolling bottle test was used to appraise the stripping resistance offered by each additive. A microscopic analysis was conducted to visually evaluate the propensity of the additives to adequately coat the surface of the aggregates. All the stabilization technologies improved the material stiffness, with the most significant improvements produced by calcium chloride salt, bentonite, lignosulfonate, and cement mixed with a mineral mixture. The stabilization additives effectively reduced permanent deformations, except for the specimens stabilized with polyurethane and bitumen. Finally, the polymer-based additives and bitumen demonstrated very good resistance to stripping, with polyurethane providing the smallest mass loss. This study documents that nontraditional stabilization technologies can provide effective alternatives to the traditional stabilizers and documents that a "one-size-fits-all" additive agent is unlikely to be developed.

show abstract

Section: Research Motivation and Objectivementioning

confidence: 99%

Stabilization of Coarse Aggregates with Traditional and Nontraditional Additives

Barbieri

Lou

Dyke

et al. 2022

J. Mater. Civ. Eng.

View full text Add to dashboard Cite

show abstract

“…The modulus of elasticity calculated based on the recoverable strain of material under repetitive loads is defined as the resilience module (M R ) of the material and is the ratio of deviator stress to recoverable strain in the three-axial test [1]. M R is the most important mechanical parameter used to characterize the subgrade, sub-base and base layers under repeated loads as the materials used in the layers exhibit permanent deformation under repeated loads [12,13].…”

Section: Introductionmentioning

confidence: 99%

Optimizing Non-Linear Granular Layer Coefficients of a Flexible Pavement for Mechanistic-Empirical Method

Bostancıoğlu

2021

Teknik Dergi

View full text Add to dashboard Cite

In recent years, mechanistic-empirical (M-E) design methods are preferred in the design of flexible pavements instead of empirical methods using equations based on the road performance tests. However, the calibration of transfer equations that convert mechanical responses to pavement life and the definition of layer materials used in M-E methods have great importance for M-E methods.In this study, mechanical analyses of a cross-section designed with the AASHTO-93 method were performed, and service life values were calculated with different empirical transfer equations. The obtained M-E design results were compared with the results calculated with the AASHTO-93 method, and transfer equations compatible with the AASHTO-93 method were determined. Among the transfer equations examined, it was found that the rutting equation of the Asphalt Institute gave the most consistent results with the AASHTO-93 method. In the mechanical analysis of the selected cross-section, granular base and sub-base layers were defined as non-linear elastic reflecting the actual in-situ conditions. K-Ɵ model was preferred for non-linear elastic layer definition, and K 1 and K 2 parameters of this model were optimized.

show abstract

“…Regarding the resilient deformation, the concepts were introduced by AASHTO in 1986 [8]. This property is often used to characterize the materials in several railway layers [9][10][11]. About the permanent deformation, an accurate estimation of the amount of cumulative settlement will benefit railway structures to avoid a mediocre performance and consequently higher annual maintenance costs [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

A geomechanics classification for the rating of railroad subgrade performance

Correia

Ramos

2021

Rail. Eng. Science

View full text Add to dashboard Cite

The type of subgrade of a railroad foundation is vital to the overall performance of the track structure. With the train speed and tonnage increase, as well as environmental changes, the evaluation and influence of subgrade are even more paramount in the railroad track structure performance. A geomechanics classification for subgrade is proposed coupling the stiffness (resilient modulus) and permanent deformation behaviour evaluated by means of repeated triaxial loading tests. This classification covers from fine- to coarse-grained soils, grouped by UIC and ASTM. For this achievement, we first summarize the main models for estimating resilient modulus and permanent deformation, including the evaluation of their robustness and their sensitivity to mechanical and environmental parameters. This is followed by the procedure required to arrive at the geomechanical classification and rating, as well as a discussion of the influence of environmental factors. This work is the first attempt to obtain a new geomechanical classification that can be a useful tool in the evaluation and modelling of the foundation of railway structures.

show abstract

Estimating resilient modulus of base aggregates for mechanistic-empirical pavement design and performance evaluation

Cited by 25 publications

References 1 publication

Stabilization of Coarse Aggregates with Traditional and Nontraditional Additives

Stabilization of Coarse Aggregates with Traditional and Nontraditional Additives

Optimizing Non-Linear Granular Layer Coefficients of a Flexible Pavement for Mechanistic-Empirical Method

A geomechanics classification for the rating of railroad subgrade performance

Contact Info

Product

Resources

About